Sample records for acute oligomer ab1-40
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Pearson-Leary, Jiah; McNay, Ewan C.
2017-01-01
Increasing evidence suggests that abnormal brain accumulation of amyloid-β1–42 (Aβ1–42) oligomers plays a causal role in Alzheimer’s disease (AD), and in particular may cause the cognitive deficits that are the hallmark of AD. In vitro, Aβ1–42 oligomers impair insulin signaling and suppress neural functioning. We previously showed that endogenous insulin signaling is an obligatory component of normal hippocampal function, and that disrupting this signaling led to a rapid impairment of spatial working memory, while delivery of exogenous insulin to the hippocampus enhanced both memory and metabolism; diet-induced insulin resistance both impaired spatial memory and prevented insulin from increasing metabolism or cognitive function. Hence, we tested the hypothesis that Aβ1–42 oligomers could acutely impair hippocampal metabolic and cognitive processes in vivo in the rat. Our findings support this hypothesis: Aβ1–42 oligomers impaired spontaneous alternation behavior while preventing the task-associated dip in hippocampal ECF glucose observed in control animals. In addition, Aβ1–42 oligomers decreased plasma membrane translocation of the insulin-sensitive glucose transporter 4 (GluT4), and impaired insulin signaling as measured by phosphorylation of Akt. These data show in vivo that Aβ1–42 oligomers can rapidly impair hippocampal cognitive and metabolic processes, and provide support for the hypothesis that elevated Aβ1–42 leads to cognitive impairment via interference with hippocampal insulin signaling. PMID:22430529
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Natural amyloid-β oligomers acutely impair the formation of a contextual fear memory in mice.
Kittelberger, Kara A; Piazza, Fabrizio; Tesco, Giuseppina; Reijmers, Leon G
2012-01-01
Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD). It has been proposed that soluble amyloid-beta (Abeta) oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss.
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Natural Amyloid-Beta Oligomers Acutely Impair the Formation of a Contextual Fear Memory in Mice
Kittelberger, Kara A.; Piazza, Fabrizio; Tesco, Giuseppina; Reijmers, Leon G.
2012-01-01
Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD). It has been proposed that soluble amyloid-beta (Abeta) oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss. PMID:22238679
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Natural amyloid-β oligomers acutely impair the formation of a contextual fear memory in mice.
Directory of Open Access Journals (Sweden)
Kara A Kittelberger
Full Text Available Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD. It has been proposed that soluble amyloid-beta (Abeta oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss.
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2010-07-01
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry34Ab1 and Cry35Ab1 proteins in corn; exemption from the requirement of a tolerance. 174.506 Section 174.506 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...
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Performance of the BioPlex 2200 HIV Ag-Ab assay for identifying acute HIV infection.
Eshleman, Susan H; Piwowar-Manning, Estelle; Sivay, Mariya V; Debevec, Barbara; Veater, Stephanie; McKinstry, Laura; Bekker, Linda-Gail; Mannheimer, Sharon; Grant, Robert M; Chesney, Margaret A; Coates, Thomas J; Koblin, Beryl A; Fogel, Jessica M
Assays that detect HIV antigen (Ag) and antibody (Ab) can be used to screen for HIV infection. To compare the performance of the BioPlex 2200 HIV Ag-Ab assay and two other Ag/Ab combination assays for detection of acute HIV infection. Samples were obtained from 24 individuals (18 from the US, 6 from South Africa); these individuals were classified as having acute infection based on the following criteria: positive qualitative RNA assay; two negative rapid tests; negative discriminatory test. The samples were tested with the BioPlex assay, the ARCHITECT HIV Ag/Ab Combo test, the Bio-Rad GS HIV Combo Ag-Ab EIA test, and a viral load assay. Twelve (50.0%) of 24 samples had RNA detected only ( > 40 to 13,476 copies/mL). Ten (43.5%) samples had reactive results with all three Ag/Ab assays, one sample was reactive with the ARCHITECT and Bio-Rad assays, and one sample was reactive with the Bio-Rad and BioPlex assays. The 11 samples that were reactive with the BioPlex assay had viral loads from 83,010 to >750,000 copies/mL; 9/11 samples were classified as Ag positive/Ab negative by the BioPlex assay. Detection of acute HIV infection was similar for the BioPlex assay and two other Ag/Ab assays. All three tests were less sensitive than a qualitative RNA assay and only detected HIV Ag when the viral load was high. The BioPlex assay detected acute infection in about half of the cases, and identified most of those infections as Ag positive/Ab negative. Copyright © 2018 Elsevier B.V. All rights reserved.
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PrP(Sc-specific antibodies with the ability to immunodetect prion oligomers.
Directory of Open Access Journals (Sweden)
Mourad Tayebi
Full Text Available The development of antibodies with binding capacity towards soluble oligomeric forms of PrPSc recognised in the aggregation process in early stage of the disease would be of paramount importance in diagnosing prion diseases before extensive neuropathology has ensued. As blood transfusion appears to be efficient in the transmission of the infectious prion agent, there is an urgent need to develop reagents that would specifically recognize oligomeric forms of the abnormally folded prion protein, PrPSc.To that end, we show that anti-PrP monoclonal antibodies (called PRIOC mAbs derived from mice immunised with native PrP-coated microbeads are able to immunodetect oligomers/multimers of PrPSc. Oligomer-specific immunoreactivity displayed by these PRIOC mAbs was demonstrated as large aggregates of immunoreactive deposits in prion-permissive neuroblastoma cell lines but not in equivalent non-infected or prn-p(0/0 cell lines. In contrast, an anti-monomer PrP antibody displayed diffuse immunoreactivity restricted to the cell membrane. Furthermore, our PRIOC mAbs did not display any binding with monomeric recombinant and cellular prion proteins but strongly detected PrPSc oligomers as shown by a newly developed sensitive and specific ELISA. Finally, PrioC antibodies were also able to bind soluble oligomers formed of Aβ and α-synuclein. These findings demonstrate the potential use of anti-prion antibodies that bind PrPSc oligomers, recognised in early stage of the disease, for the diagnosis of prion diseases in blood and other body fluids.
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Directory of Open Access Journals (Sweden)
Amanda C. Crisostomo
2015-09-01
Aβ1-40 soluble oligomers are produced that are suitable for biophysical studies requiring sufficient transient stability to exist in their “native” conformation in biological phosphate-saline buffers for extended periods of time. The production involves an initial preparation of highly monomeric Aβ in a phosphate saline buffer that transitions to fibrils and oligomers through time incubation alone, without added detergents or non-aqueous chemicals. This criteria ensures that the only difference between initial monomeric Aβ reactant and subsequent Aβ oligomer products is their degree of peptide assembly. A number of chemical and biophysical methods were used to characterize the monomeric reactants and soluble oligomer and amyloid fibril products, including chemical cross-linking, Western blots, fraction solubility, thioflvain T binding, size exclusion chromatography, transmission electron micrscopy, circular dichroism spectroscopy, and fluorescence resonance energy transfer.
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International Nuclear Information System (INIS)
Yu, Z.G.; Smith, D.L.; Saxena, A.; Bishop, A.R.
1997-01-01
The electronic transmission across metal/conjugated-oligomer/metal structures in the presence of lattice fluctuations is studied for short oligomer chains. The lattice fluctuations are approximated by static white noise disorder. Resonant transmission occurs when the energy of an incoming electron coincides with a discrete electronic level of the oligomer. The corresponding transmission peak diminishes in intensity with increasing disorder strength. Because of disorder there is an enhancement of the electronic transmission for energies that lie within the electronic gap of the oligomer. If fluctuations are sufficiently strong, a transmission peak within the gap is found at the midgap energy E=0 for degenerate conjugated oligomers (e.g., trans-polyacetylene) and E≠0 for AB-type degenerate oligomers. These results can be interpreted in terms of soliton-antisoliton states created by lattice fluctuations. copyright 1997 The American Physical Society
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High-resolution NMR characterization of low abundance oligomers of amyloid-β without purification.
Kotler, Samuel A; Brender, Jeffrey R; Vivekanandan, Subramanian; Suzuki, Yuta; Yamamoto, Kazutoshi; Monette, Martine; Krishnamoorthy, Janarthanan; Walsh, Patrick; Cauble, Meagan; Holl, Mark M Banaszak; Marsh, E Neil G; Ramamoorthy, Ayyalusamy
2015-07-03
Alzheimer's disease is characterized by the misfolding and self-assembly of the amyloidogenic protein amyloid-β (Aβ). The aggregation of Aβ leads to diverse oligomeric states, each of which may be potential targets for intervention. Obtaining insight into Aβ oligomers at the atomic level has been a major challenge to most techniques. Here, we use magic angle spinning recoupling (1)H-(1)H NMR experiments to overcome many of these limitations. Using (1)H-(1)H dipolar couplings as a NMR spectral filter to remove both high and low molecular weight species, we provide atomic-level characterization of a non-fibrillar aggregation product of the Aβ1-40 peptide using non-frozen samples without isotopic labeling. Importantly, this spectral filter allows the detection of the specific oligomer signal without a separate purification procedure. In comparison to other solid-state NMR techniques, the experiment is extraordinarily selective and sensitive. A resolved 2D spectra could be acquired of a small population of oligomers (6 micrograms, 7% of the total) amongst a much larger population of monomers and fibers (93% of the total). By coupling real-time (1)H-(1)H NMR experiments with other biophysical measurements, we show that a stable, primarily disordered Aβ1-40 oligomer 5-15 nm in diameter can form and coexist in parallel with the well-known cross-β-sheet fibrils.
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Aβ42 oligomers selectively disrupt neuronal calcium release.
Lazzari, Cristian; Kipanyula, Maulilio J; Agostini, Mario; Pozzan, Tullio; Fasolato, Cristina
2015-02-01
Accumulation of amyloid-β (Aβ) peptides correlates with aging and progression of Alzheimer's disease (AD). Aβ peptides, which cause early synaptic dysfunctions, spine loss, and memory deficits, also disturb intracellular Ca(2+) homeostasis. By cytosolic and endoplasmic reticulum Ca(2+) measurements, we here define the short-term effects of synthetic Aβ42 on neuronal Ca(2+) dynamics. When applied acutely at submicromolar concentration, as either oligomers or monomers, Aβ42 did not cause Ca(2+) release or Ca(2+) influx. Similarly, 1-hour treatment with Aβ42 modified neither the resting cytosolic Ca(2+) level nor the long-lasting Ca(2+) influx caused by KCl-induced depolarization. In contrast, Aβ42 oligomers, but not monomers, significantly altered Ca(2+) release from stores with opposite effects on inositol 1,4,5-trisphosphate (IP3)- and caffeine-induced Ca(2+) mobilization without alteration of the total store Ca(2+) content. Ca(2+) dysregulation by Aβ42 oligomers involves metabotropic glutamate receptor 5 and requires network activity and the intact exo-endocytotic machinery, being prevented by tetrodotoxin and tetanus toxin. These findings support the idea that Ca(2+) store dysfunction is directly involved in Aβ42 neurotoxicity and represents a potential therapeutic target in AD-like dementia. Copyright © 2015 Elsevier Inc. All rights reserved.
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Baek, Minkyung; Park, Taeyong; Heo, Lim; Park, Chiwook; Seok, Chaok
2017-07-03
Homo-oligomerization of proteins is abundant in nature, and is often intimately related with the physiological functions of proteins, such as in metabolism, signal transduction or immunity. Information on the homo-oligomer structure is therefore important to obtain a molecular-level understanding of protein functions and their regulation. Currently available web servers predict protein homo-oligomer structures either by template-based modeling using homo-oligomer templates selected from the protein structure database or by ab initio docking of monomer structures resolved by experiment or predicted by computation. The GalaxyHomomer server, freely accessible at http://galaxy.seoklab.org/homomer, carries out template-based modeling, ab initio docking or both depending on the availability of proper oligomer templates. It also incorporates recently developed model refinement methods that can consistently improve model quality. Moreover, the server provides additional options that can be chosen by the user depending on the availability of information on the monomer structure, oligomeric state and locations of unreliable/flexible loops or termini. The performance of the server was better than or comparable to that of other available methods when tested on benchmark sets and in a recent CASP performed in a blind fashion. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.
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Directory of Open Access Journals (Sweden)
Aamir Razaq
Full Text Available Highly porous polypyrrole (PPy-nanocellulose paper sheets have been evaluated as inexpensive and disposable electrochemically controlled three-dimensional solid phase extraction materials. The composites, which had a total anion exchange capacity of about 1.1 mol kg(-1, were used for extraction and subsequent release of negatively charged fluorophore tagged DNA oligomers via galvanostatic oxidation and reduction of a 30-50 nm conformal PPy layer on the cellulose substrate. The ion exchange capacity, which was, at least, two orders of magnitude higher than those previously reached in electrochemically controlled extraction, originated from the high surface area (i.e. 80 m(2 g(-1 of the porous composites and the thin PPy layer which ensured excellent access to the ion exchange material. This enabled the extractions to be carried out faster and with better control of the PPy charge than with previously employed approaches. Experiments in equimolar mixtures of (dT(6, (dT(20, and (dT(40 DNA oligomers showed that all oligomers could be extracted, and that the smallest oligomer was preferentially released with an efficiency of up to 40% during the reduction of the PPy layer. These results indicate that the present material is very promising for the development of inexpensive and efficient electrochemically controlled ion-exchange membranes for batch-wise extraction of biomolecules.
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Agarwal, Manisha; Bakhshi, Sameer; Dwivedi, Sadanand N; Kabra, Madhulika; Shukla, Rashmi; Seth, Rachna
2018-06-01
Cyclin dependent kinase inhibitor 2A/B (CDKN2A/B) genes are implicated in many malignancies including acute lymphoblastic leukemia (ALL). These tumor suppressor genes, with a key regulatory role in cell cycle are located on chromosome 9p21.3. Previous studies involving CDKN2A/B gene deletions have shown mixed associations with survival outcome in childhood ALL. Hundred and four newly diagnosed children with ALL (1-14 years) were enrolled in this study. Genomic DNA from pretreatment bone marrow/peripheral blood samples of these children was investigated for copy number alterations in CDKN2A/B genes using multiplex ligation dependent probe amplification assay. Immunophenotype subtyping and cytogenetic and molecular analysis of ALL was performed at start of induction chemotherapy in all children. Children were monitored for response to prednisolone (Day 8), complete morphological remission, and minimal residual disease at the end of induction. The minimum postinduction follow-up period was 6 months. CDKN2A/B deletions were seen in 19.8% (18/91) of B lineage acute lymphoblastic leukemia (B-ALL) and 38.5% (5/13) of T lineage acute lymphoblastic leukemia (T-ALL). Monoallelic CDKN2A/B deletions were found in 61.1% of total deletions in B-ALL while all the children with T-ALL harbored biallelic deletions. The prevalence of CDKN2A/B gene deletions was found to be significantly higher in older children (P = 0.002), in those with higher leukocyte count (P = 0.037), and in National Cancer Institute high risk group patients (P = 0.001) in the B-ALL subgroup. Hazard ratio was significantly high for children with CDKN2A/B deletions in total cohort (P = 0.004). Children with CDKN2A/B deletion had significantly lesser event free survival (P = 0.03). CDKN2A/B deletions were significantly more prevalent in T-ALL subgroup and were found to have higher hazard ratio and lesser event free survival in total cohort in our study. © 2018 Wiley Periodicals, Inc.
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Energy Technology Data Exchange (ETDEWEB)
Taneo, Jun; Adachi, Takumi [Department of Animal Development and Physiology, Kyoto University, Yoshida-Konoe, Sakyo, Kyoto 606-8501 (Japan); Yoshida, Aiko; Takayasu, Kunio [Responses to Environmental Signals and Stresses, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe, Sakyo, Kyoto, Kyoto 606-8501 (Japan); Takahara, Kazuhiko, E-mail: ktakahar@zoo.zool.kyoto-u.ac.jp [Department of Animal Development and Physiology, Kyoto University, Yoshida-Konoe, Sakyo, Kyoto 606-8501 (Japan); Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), Tokyo 102-0081 (Japan); Inaba, Kayo [Department of Animal Development and Physiology, Kyoto University, Yoshida-Konoe, Sakyo, Kyoto 606-8501 (Japan); Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), Tokyo 102-0081 (Japan)
2015-03-13
Amyloid β (Aβ) peptide, a causative agent of Alzheimer's disease, forms two types of aggregates: oligomers and fibrils. These aggregates induce inflammatory responses, such as interleukin-1β (IL-1β) production by microglia, which are macrophage-like cells located in the brain. In this study, we examined the effect of the two forms of Aβ aggregates on IL-1β production in mouse primary microglia. We prepared Aβ oligomer and fibril from Aβ (1–42) peptide in vitro. We analyzed the characteristics of these oligomers and fibrils by electrophoresis and atomic force microscopy. Interestingly, Aβ oligomers but not Aβ monomers or fibrils induced robust IL-1β production in the presence of lipopolysaccharide. Moreover, Aβ oligomers induced endo/phagolysosome rupture, which released cathepsin B into the cytoplasm. Aβ oligomer-induced IL-1β production was inhibited not only by the cathepsin B inhibitor CA-074-Me but also by the reactive oxygen species (ROS) inhibitor N-acetylcysteine. Random chemical crosslinking abolished the ability of the oligomers to induce IL-1β. Thus, multimerization and fibrillization causes Aβ oligomers to lose the ability to induce IL-1β. These results indicate that Aβ oligomers, but not fibrils, induce IL-1β production in primary microglia in a cathepsin B- and ROS-dependent manner. - Highlights: • We prepared amyloid β (Aβ) fibrils with minimum contamination of Aβ oligomers. • Primary microglia (MG) produced IL-1β in response to Aβ oligomers, but not fibrils. • Only Aβ oligomers induced leakage of cathepsin B from endo/phagolysosomes. • IL-1β production in response to Aβ oligomers depended on both cathepsin B and ROS. • Crosslinking reduced the ability of the Aβ oligomers to induce IL-1β from MG.
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2010-07-01
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry1Ab protein in all plants; exemption from the requirement of a tolerance. 174.511 Section 174.511 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances...
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Tau oligomers impair memory and induce synaptic and mitochondrial dysfunction in wild-type mice
Directory of Open Access Journals (Sweden)
Jackson George R
2011-06-01
Full Text Available Abstract Background The correlation between neurofibrillary tangles of tau and disease progression in the brains of Alzheimer's disease (AD patients remains an area of contention. Innovative data are emerging from biochemical, cell-based and transgenic mouse studies that suggest that tau oligomers, a pre-filament form of tau, may be the most toxic and pathologically significant tau aggregate. Results Here we report that oligomers of recombinant full-length human tau protein are neurotoxic in vivo after subcortical stereotaxic injection into mice. Tau oligomers impaired memory consolidation, whereas tau fibrils and monomers did not. Additionally, tau oligomers induced synaptic dysfunction by reducing the levels of synaptic vesicle-associated proteins synaptophysin and septin-11. Tau oligomers produced mitochondrial dysfunction by decreasing the levels of NADH-ubiquinone oxidoreductase (electron transport chain complex I, and activated caspase-9, which is related to the apoptotic mitochondrial pathway. Conclusions This study identifies tau oligomers as an acutely toxic tau species in vivo, and suggests that tau oligomers induce neurodegeneration by affecting mitochondrial and synaptic function, both of which are early hallmarks in AD and other tauopathies. These results open new avenues for neuroprotective intervention strategies of tauopathies by targeting tau oligomers.
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Computational Design of High-χ Block Oligomers for Accessing 1 nm Domains.
Chen, Qile P; Barreda, Leonel; Oquendo, Luis E; Hillmyer, Marc A; Lodge, Timothy P; Siepmann, J Ilja
2018-05-22
Molecular dynamics simulations are used to design a series of high-χ block oligomers (HCBOs) that can self-assemble into a variety of mesophases with domain sizes as small as 1 nm. The exploration of these oligomers with various chain lengths, volume fractions, and chain architectures at multiple temperatures reveals the presence of ordered lamellae, perforated lamellae, and hexagonally packed cylinders. The achieved periods are as small as 3.0 and 2.1 nm for lamellae and cylinders, respectively, which correspond to polar domains of approximately 1 nm. Interestingly, the detailed phase behavior of these oligomers is distinct from that of either solvent-free surfactants or block polymers. The simulations reveal that the behavior of these HCBOs is a product of an interplay between both "surfactant factors" (headgroup interactions, chain flexibility, and interfacial curvature) and "block polymer factors" (χ, chain length N, and volume fraction f). This insight promotes the understanding of molecular features pivotal for mesophase formation at the sub-5 nm length scale, which facilitates the design of HCBOs tailored toward particular desired morphologies.
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De Haan, David O; Tapavicza, Enrico; Riva, Matthieu; Cui, Tianqu; Surratt, Jason D; Smith, Adam C; Jordan, Mary-Caitlin; Nilakantan, Shiva; Almodovar, Marisol; Stewart, Tiffany N; de Loera, Alexia; De Haan, Audrey C; Cazaunau, Mathieu; Gratien, Aline; Pangui, Edouard; Doussin, Jean-François
2018-04-03
Aqueous methylglyoxal chemistry has often been implicated as an important source of oligomers in atmospheric aerosol. Here we report on chemical analysis of brown carbon aerosol particles collected from cloud cycling/photolysis chamber experiments, where gaseous methylglyoxal and methylamine interacted with glycine, ammonium, or methylammonium sulfate seed particles. Eighteen N-containing oligomers were identified in the particulate phase by liquid chromatography/diode array detection/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry. Chemical formulas were determined and, for 6 major oligomer products, MS 2 fragmentation spectra were used to propose tentative structures and mechanisms. Electronic absorption spectra were calculated for six tentative product structures by an ab initio second order algebraic-diagrammatic-construction/density functional theory approach. For five structures, matching calculated and measured absorption spectra suggest that they are dominant light-absorbing species at their chromatographic retention times. Detected oligomers incorporated methylglyoxal and amines, as expected, but also pyruvic acid, hydroxyacetone, and significant quantities of acetaldehyde. The finding that ∼80% (by mass) of detected oligomers contained acetaldehyde, a methylglyoxal photolysis product, suggests that daytime methylglyoxal oligomer formation is dominated by radical addition mechanisms involving CH 3 CO*. These mechanisms are evidently responsible for enhanced browning observed during photolytic cloud events.
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2010-07-01
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis eCry3.1Ab protein in corn; temporary exemption from the requirement of a tolerance. 174.532 Section 174.532 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...
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International Nuclear Information System (INIS)
Chen Jing; Jiang Li; Lu Ya
2005-01-01
Objective: To determine the clinical significance of combined detection of multiple serum antibodies in infertile women. Methods; Serum multiple antibodies were examined in 120 infertile women, including 88 failed to get pregnancy and 32 with repeated spontaneous abortion. The antibodies tested were: (1) anti-sperm antibody (AsAb) (2) endometrial antibody (EmAb) (3) anti-cardiophospholipid antibody (AcAb) (4) Anti-ovarian antibody (AoAb) and Toxoplasmosis antibody (ToxAb). Results: In 48 of the infertile women, none of the five antibodies were positive (40% of 120). The rest were: one antibody positive--38/120 or 31.6%; two antibodies positive--31/120 or 25.83%, three and four antibodies positive--4/120 or 3.33%. None of the women were positive with all five antibodies. Conclusion: Immune factor was the chief cause of infertility in women. (authors)
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Johnson, K D; Campbell, L A; Lepping, M D; Rule, D M
2017-06-01
Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), and northern corn rootworm, Diabrotica barberi Smith and Lawrence (Coleoptera: Chrysomelidae), are important insect pests in corn, Zea mays L. For more than a decade, growers have been using transgenic plants expressing proteins from the bacterium Bacillus thuringiensis (Bt) to protect corn roots from feeding. In 2011, western corn rootworm populations were reported to have developed resistance to Bt hybrids expressing Cry3Bb1 and later found to be cross-resistant to hybrids expressing mCry3A and eCry3.1Ab. The identification of resistance to Cry3 (Cry3Bb1, mCry3A, and eCry3.1Ab) hybrids led to concerns about durability and efficacy of products with single traits and of products containing a pyramid of a Cry3 protein and the binary Bt proteins Cry34Ab1 and Cry35Ab1. From 2012 to 2014, 43 field trials were conducted across the central United States to estimate root protection provided by plants expressing Cry34Ab1/Cry35Ab1 alone (Herculex RW) or pyramided with Cry3Bb1 (SmartStax). These technologies were evaluated with and without soil-applied insecticides to determine if additional management measures provided benefit where Cry3 performance was reduced. Trials were categorized for analysis based on rootworm damage levels on Cry3-expressing hybrids and rootworm feeding pressure within each trial. Across scenarios, Cry34Ab1/Cry35Ab1 hybrids provided excellent root protection. Pyramided traits provided greater root and yield protection than non-Bt plus a soil-applied insecticide, and only in trials where larval feeding pressure exceeded two nodes of damage did Cry34Ab1/Cry35Ab1 single-trait hybrids and pyramided hybrids show greater root protection from the addition of soil-applied insecticides. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Humans Can Taste Glucose Oligomers Independent of the hT1R2/hT1R3 Sweet Taste Receptor.
Lapis, Trina J; Penner, Michael H; Lim, Juyun
2016-08-23
It is widely accepted that humans can taste mono- and disaccharides as sweet substances, but they cannot taste longer chain oligo- and polysaccharides. From the evolutionary standpoint, the ability to taste starch or its oligomeric hydrolysis products would be highly adaptive, given their nutritional value. Here, we report that humans can taste glucose oligomer preparations (average degree of polymerization 7 and 14) without any other sensorial cues. The same human subjects could not taste the corresponding glucose polymer preparation (average degree of polymerization 44). When the sweet taste receptor was blocked by lactisole, a known sweet inhibitor, subjects could not detect sweet substances (glucose, maltose, and sucralose), but they could still detect the glucose oligomers. This suggests that glucose oligomer detection is independent of the hT1R2/hT1R3 sweet taste receptor. Human subjects described the taste of glucose oligomers as "starchy," while they describe sugars as "sweet." The dose-response function of glucose oligomer was also found to be indistinguishable from that of glucose on a molar basis. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers
Dingemans, Theodorus J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)
2009-01-01
Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures.
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Accumulation of oligomer-prone α-synuclein exacerbates synaptic and neuronal degeneration in vivo.
Rockenstein, Edward; Nuber, Silke; Overk, Cassia R; Ubhi, Kiren; Mante, Michael; Patrick, Christina; Adame, Anthony; Trejo-Morales, Margarita; Gerez, Juan; Picotti, Paola; Jensen, Poul H; Campioni, Silvia; Riek, Roland; Winkler, Jürgen; Gage, Fred H; Winner, Beate; Masliah, Eliezer
2014-05-01
In Parkinson's disease and dementia with Lewy bodies, α-synuclein aggregates to form oligomers and fibrils; however, the precise nature of the toxic α-synuclein species remains unclear. A number of synthetic α-synuclein mutations were recently created (E57K and E35K) that produce species of α-synuclein that preferentially form oligomers and increase α-synuclein-mediated toxicity. We have shown that acute lentiviral expression of α-synuclein E57K leads to the degeneration of dopaminergic neurons; however, the effects of chronic expression of oligomer-prone α-synuclein in synapses throughout the brain have not been investigated. Such a study could provide insight into the possible mechanism(s) through which accumulation of α-synuclein oligomers in the synapse leads to neurodegeneration. For this purpose, we compared the patterns of neurodegeneration and synaptic damage between a newly generated mThy-1 α-synuclein E57K transgenic mouse model that is prone to forming oligomers and the mThy-1 α-synuclein wild-type mouse model (Line 61), which accumulates various forms of α-synuclein. Three lines of α-synuclein E57K (Lines 9, 16 and 54) were generated and compared with the wild-type. The α-synuclein E57K Lines 9 and 16 were higher expressings of α-synuclein, similar to α-synuclein wild-type Line 61, and Line 54 was a low expressing of α-synuclein compared to Line 61. By immunoblot analysis, the higher-expressing α-synuclein E57K transgenic mice showed abundant oligomeric, but not fibrillar, α-synuclein whereas lower-expressing mice accumulated monomeric α-synuclein. Monomers, oligomers, and fibrils were present in α-synuclein wild-type Line 61. Immunohistochemical and ultrastructural analyses demonstrated that α-synuclein accumulated in the synapses but not in the neuronal cells bodies, which was different from the α-synuclein wild-type Line 61, which accumulates α-synuclein in the soma. Compared to non-transgenic and lower-expressing mice, the
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Directory of Open Access Journals (Sweden)
Andrew C Harris
Full Text Available Passive immunization with monoclonal antibodies (mAbs against (+-methamphetamine (METH is being evaluated for the treatment of METH addiction. A human/mouse chimeric form of the murine anti-METH mAb7F9 has entered clinical trials. This study examined the effects of murine mAb7F9 on certain addiction-related behavioral effects of METH in rats as measured using intracranial self-stimulation (ICSS. Initial studies indicated that acute METH (0.1-0.56 mg/kg, s.c. lowered the minimal (threshold stimulation intensity that maintained ICSS. METH (0.3 mg/kg, s.c. also blocked elevations in ICSS thresholds (anhedonia-like behavior during spontaneous withdrawal from a chronic METH infusion (10 mg/kg/day x 7 days. In studies examining effects of i.v. pretreatment with mAb7F9 (at 30, 100, or 200 mg/kg, 200 mg/kg blocked the ability of an initial injection of METH (0.3 mg/kg, s.c. to reduce baseline ICSS thresholds, but was less capable of attenuating the effect of subsequent daily injections of METH. MAb7F9 (200 mg/kg also produced a small but significant reduction in the ability of METH (0.3 mg/kg, s.c. to reverse METH withdrawal-induced elevations in ICSS thresholds. These studies demonstrate that mAb7F9 can partially attenuate some addiction-related effects of acute METH in an ICSS model, and provide some support for the therapeutic potential of mAb7F9 for the treatment of METH addiction.
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PIPERIDINE OLIGOMERS AND COMBINATORIAL LIBRARIES THEREOF
DEFF Research Database (Denmark)
1999-01-01
The present invention relates to piperidine oligomers, methods for the preparation of piperidine oligomers and compound libraries thereof, and the use of piperidine oligomers as drug substances. The present invention also relates to the use of combinatorial libraries of piperidine oligomers...... in libraries (arrays) of compounds especially suitable for screening purposes....
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A fragment-based approach towards ab-initio treatment of polymeric ...
Indian Academy of Sciences (India)
Reshma S Pingale
2017-06-20
Jun 20, 2017 ... Keywords. π-Conjugated polymer; divide and conquer; ab-initio; fragmentation. PACS Nos 31.15.A−; 36.20. ... cut the parent system into a set of overlapping small fragments and .... some oligomers, we approached the problem by increas- ..... Financial support of DST, Govt. of India, New Delhi, in the form of ...
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Voon, Lee Ken; Pang, Suh Cem; Chin, Suk Fun
2016-05-20
Cellulose extracted from printed paper wastes were selectively depolymerized under controlled conditions into cello-oligomers of controllable chain lengths via dissolution in an ionic liquid, 1-allyl-3-methylimidazolium chloride (AMIMCl), and in the presence of an acid catalyst, Amberlyst 15DRY. The depolymerization process was optimized against reaction temperature, concentration of acid catalyst, and reaction time. Despite rapid initial depolymerization process, the rate of cellulose depolymerization slowed down gradually upon prolonged reaction time, with 75.0 wt% yield of regenerated cello-oligomers (mean Viscosimetric Degree of Polymerization value of 81) obtained after 40 min. The depolymerization of cellulose fibers at 80 °C appeared to proceed via a second-order kinetic reaction with respect to the catalyst concentration of 0.23 mmol H3O(+). As such, the cellulose depolymerization process could afford some degree of control on the degree of polymerization or chain lengths of cello-oligomers formed. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Bogdan Barz
Full Text Available Amyloid β-protein (Aβ is central to the pathology of Alzheimer's disease. A 5% difference in the primary structure of the two predominant alloforms, Aβ(1-40 and Aβ(1-42, results in distinct assembly pathways and toxicity properties. Discrete molecular dynamics (DMD studies of Aβ(1-40 and Aβ(1-42 assembly resulted in alloform-specific oligomer size distributions consistent with experimental findings. Here, a large ensemble of DMD-derived Aβ(1-40 and Aβ(1-42 monomers and dimers was subjected to fully atomistic molecular dynamics (MD simulations using the OPLS-AA force field combined with two water models, SPCE and TIP3P. The resulting all-atom conformations were slightly larger, less compact, had similar turn and lower β-strand propensities than those predicted by DMD. Fully atomistic Aβ(1-40 and Aβ(1-42 monomers populated qualitatively similar free energy landscapes. In contrast, the free energy landscape of Aβ(1-42 dimers indicated a larger conformational variability in comparison to that of Aβ(1-40 dimers. Aβ(1-42 dimers were characterized by an increased flexibility in the N-terminal region D1-R5 and a larger solvent exposure of charged amino acids relative to Aβ(1-40 dimers. Of the three positively charged amino acids, R5 was the most and K16 the least involved in salt bridge formation. This result was independent of the water model, alloform, and assembly state. Overall, salt bridge propensities increased upon dimer formation. An exception was the salt bridge propensity of K28, which decreased upon formation of Aβ(1-42 dimers and was significantly lower than in Aβ(1-40 dimers. The potential relevance of the three positively charged amino acids in mediating the Aβ oligomer toxicity is discussed in the light of available experimental data.
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Homology of ab1 and ab3 monoclonal antibodies that neutralize Semliki Forest virus
Fernandez, IM; Bos, NA; Harmsen, M; Verheul, AFM; Snippe, H; Kraaijeveld, CA
2001-01-01
A noninternal image monoclonal antiidiotypic antibody (ab2 mAb), designated 1,13A321, that had proved its efficacy as vaccine against infection with Semliki Forest virus (SFV) in BALB/c mice, was used as immunogen to generate a panel of SFV-neutralizing monoclonal anti-anti-idiotypic antibodies (ab3
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International Nuclear Information System (INIS)
Rubin, Yu.V.; Belous, L.F.
2012-01-01
Self-associates of nucleic acid components (stacking trimers and tetramers of the base pairs of nucleic acids) and short fragments of nucleic acids are nanoparticles (linear sizes of these particles are more than 10 A). Modern quantum-mechanical methods and softwares allow one to perform ab initio calculations of the systems consisting of 150-200 atoms with enough large basis sets (for example, 6-31G * ). The aim of this work is to reveal the peculiarities of molecular and electronic structures, as well as the energy features of nanoparticles of nucleic acid components. We had carried out ab initio calculations of the molecular structure and interactions in the stacking dimer, trimer, and tetramer of nucleic base pairs and in the stacking (TpG)(ApC) dimer and (TpGpC) (ApCpG) trimer of nucleotides, which are small DNA fragments. The performed calculations of molecular structures of dimers and trimers of nucleotide pairs showed that the interplanar distance in the structures studied is equal to 3.2 A on average, and the helical angle in a trimer is approximately equal to 30 o : The distance between phosphor atoms in neighboring chains is 13.1 A. For dimers and trimers under study, we calculated the horizontal interaction energies. The analysis of interplanar distances and angles between nucleic bases and their pairs in the calculated short oligomers of nucleic acid base pairs (stacking dimer, trimer, and tetramer) has been carried out. Studies of interactions in the calculated short oligomers showed a considerable role of the cross interaction in the stabilization of the structures. The contribution of cross interactions to the horizontal interactions grows with the length of an oligomer. Nanoparticle components get electric charges in nanoparticles. Longwave low-intensity bands can appear in the electron spectra of nanoparticles.
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Energy Technology Data Exchange (ETDEWEB)
Barannikov, Vladimir P., E-mail: vpb@isc-ras.ru [Institute of Solution Chemistry, Russian Academy of Sciences, Academicheskaya Str. 1, Ivanovo 153045 (Russian Federation); Guseynov, Sabir S.; Vyugin, Anatoliy I. [Institute of Solution Chemistry, Russian Academy of Sciences, Academicheskaya Str. 1, Ivanovo 153045 (Russian Federation)
2011-12-15
Highlights: > Solvation enthalpy is found for ethylene oxide oligomers in chloroform and methanol. > Coefficients of solute-solute interaction are determined for oligomers in methanol. > Enthalpies of hydrogen bonding of oligomers with chloroform and water are estimated. > Additivity scheme is developed for describing enthalpies of solvation of oligomers. - Abstract: The enthalpies of solution and solvation of ethylene oxide oligomers CH{sub 3}O(CH{sub 2}CH{sub 2}O){sub n}CH{sub 3} (n = 1 to 4) in methanol and chloroform have been determined from calorimetric measurements at T = 298.15 K. The enthalpic coefficients of pairwise solute-solute interaction for methanol solutions have been calculated. The enthalpic characteristics of the oligomers in methanol, chloroform, water and tetrachloromethane have been compared. The hydrogen bonding of the oligomers with chloroform and water molecules is exhibited in the values of solvation enthalpy and coefficient of solute-solute interaction. This effect is not observed for methanol solvent. The thermochemical data evidence an existence of multi-centred hydrogen bonds in associates of polyethers with the solvent molecules. Enthalpies of hydrogen bonding of the oligomers with chloroform and water have been estimated. The additivity scheme has been developed to describe the enthalpies of solvation of ethylene oxide oligomers, unbranched monoethers and n-alkanes in chloroform, methanol, water, and tetrachloromethane. The correction parameters for contribution of repeated polar groups and correction term for methoxy-compounds have been introduced. The obtained group contributions permit to describe the enthalpies of solvation of unbranched monoethers and ethylene oxide oligomers in the solvents with standard deviation up to 0.6 kJ . mol{sup -1}. The values of group contributions and corrections are strongly influenced by solvent properties.
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Characteristics of tau oligomers
Directory of Open Access Journals (Sweden)
Yan eRen
2013-07-01
Full Text Available In Alzheimer disease (AD and other tauopathies, microtubule-associated protein tau becomes hyperphosphorylated, undergoes conformational changes, aggregates, eventually becoming neurofibrillary tangles (NFTs. As accumulating evidence suggests that NFTs themselves may not be toxic, attention is now turning toward the role of intermediate tau oligomers in AD pathophysiology. Sarkosyl extraction is a standard protocol for investigating insoluble tau aggregates in brains. There is a growing consensus that sarkosyl-insoluble tau correlates with the pathological features of tauopathy. While sarkosyl-insoluble tau from tauopathy brains has been well characterized as a pool of filamentous tau, other dimers, multimers, and granules of tau are much less well understood. There are protocols for identifying these tau oligomers. In this mini review, we discuss the characteristics of tau oligomers isolated via different methods and materials.
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Amyloid-β oligomer detection by ELISA in cerebrospinal fluid and brain tissue.
Bruggink, Kim A; Jongbloed, Wesley; Biemans, Elisanne A L M; Veerhuis, Rob; Claassen, Jurgen A H R; Kuiperij, H Bea; Verbeek, Marcel M
2013-02-15
Amyloid-β (Aβ) deposits are important pathological hallmarks of Alzheimer's disease (AD). Aβ aggregates into fibrils; however, the intermediate oligomers are believed to be the most neurotoxic species and, therefore, are of great interest as potential biomarkers. Here, we have developed an enzyme-linked immunosorbent assay (ELISA) specific for Aβ oligomers by using the same capture and (labeled) detection antibody. The ELISA predominantly recognizes relatively small oligomers (10-25 kDa) and not monomers. In brain tissue of APP/PS1 transgenic mice, we found that Aβ oligomer levels increase with age. However, for measurements in human samples, pretreatment to remove human anti-mouse antibodies (HAMAs) was required. In HAMA-depleted human hippocampal extracts, the Aβ oligomer concentration was significantly increased in AD compared with nondemented controls. Aβ oligomer levels could also be quantified in pretreated cerebrospinal fluid (CSF) samples; however, no difference was detected between AD and control groups. Our data suggest that levels of small oligomers might not be suitable as biomarkers for AD. In addition, we demonstrate the importance of avoiding HAMA interference in assays to quantify Aβ oligomers in human body fluids. Copyright © 2012 Elsevier Inc. All rights reserved.
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Electron beam curing of acrylic oligomers
International Nuclear Information System (INIS)
Seto, J.; Arakawa, S.; Ishimoto, C.; Miyashita, M.; Nagai, T.; Noguchi, T.; Shibata, A.
1984-01-01
The electron-beam curing process of acrylic oligomers, with and without γ-Fe 2 O 3 pigment filler and blended linear polymer, was investigated in terms of molecular structure and reaction mechanism. The polymerized fraction of trimethylolpropane-triacrylate (TMPTA) oligomers increases with increasing total dose, and is independent of the dose rate. Since the reaction rate is linearly dependent on the dose rate, the reaction mechanism involves monomolecular termination. The reaction rate does not depend on the number of functional groups of the oligomer at low doses, but above 0.3 Mrad the rate is slower for oligomers of higher functionality. A gel is formed more readily upon curing of a polyfunctional than a monofunctional oligomer, especially at high conversion to polymer; the resulting loss of flexibility of the polymer chains slows the reaction. Decrease of the molecular weight per functional group results in lower conversion; this is also due to the loss of chain flexibility, which is indicated as well by a higher glass-transition temperature. Modification of the acrylate oligomers with urethane results in more effective cross-linking reactions because of the more rigid molecular chains. Addition of γ-Fe 2 O 3 pigment reduces the reaction rate very little, but has the effect of providing added structural integrity, as indicated by the decrease of solvent-extractable material and the improvement of anti-abrasion properties. However, the flexibility of the coating and its adhesion to a PET base film are diminished. To increase the flexibility, linear polyvinylchloride and/or polyurethane were added to the acrylic oligomers. Final conversion to polymer was nearly 100 percent, and a higher elastic modulus and better antiabrasion properties were realized
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Directory of Open Access Journals (Sweden)
Yusro Nuri Fawzya
2009-06-01
Full Text Available Penelitian ini merupakan sebagian dari rangkaian penelitian mengenai eksplorasi enzim kitinolitik dari mikroba lingkungan laut, khususnya dari limbah udang. Tujuan penelitian ini adalah untuk mengidentifikasi isolat bakteri KPU 2123 dari limbah udang, mengkarakterisasi dan mengaplikasikan enzim kitosanase yang dihasilkan oleh bakteri tersebut untuk produksi oligomer kitosan dan menguji bioaktivitas oligomer kitosan tersebut sebagai antitumor dan antibakteri. Karakterisasi enzim dilakukan dengan menguji aktivitas enzim pada berbagai suhu dan pH. Selain itu juga ditentukan besarnya aktivitas yang tersisa setelah enzim diinkubasi pada suhu dan lama waktu tertentu. Pengaruh ion logam terhadap aktivitas enzim juga dilihat dengan mereaksikan enzim dengan 1 mM ion logam dalam bentuk larutan khlorida. Hasil penelitian menunjukkan bahwa berdasarkan analisis gen 16S-rRNA, isolat bakteri KPU 2123 memiliki kemiripan 95% dengan Stanotrophomonas maltophilia. Enzim kitosanase dari isolat ini bekerja optimal pada suhu 50 ºC dan pH 6. Enzim ini cukup stabil pada suhu 37 ºC selama 120 menit. Penambahan ion logam berpengaruh terhadap aktivitas enzim. Ion logam Zn²+ (sebagai garam klorida 1 mM menghambat 100% aktivitas enzim tersebut. Penggunaan enzim kitosanase dalam menghidrolisis substrat kitosan, menghasilkan oligomer kitosan yang mengandung tetramer, pentamer dan heksamer Oligor kitosan tersebut mampu menghambat pertumbuhan bakteri Staphylococcus aureus sebesar 10,06% dan dapat menyebabkan kematian sel HeLa dengan LC50 pada dosis 120 ppm.
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Thio-urethane oligomers improve the properties of light-cured resin cements.
Bacchi, Ataís; Consani, Rafael L; Martim, Gedalias C; Pfeifer, Carmem S
2015-05-01
Thio-urethanes were synthesized by combining 1,6-hexanediol-diissocyante (aliphatic) with pentaerythritol tetra-3-mercaptopropionate (PETMP) or 1,3-bis(1-isocyanato-1-methylethyl)benzene (aromatic) with trimethylol-tris-3-mercaptopropionate (TMP), at 1:2 isocyanate:thiol, leaving pendant thiols. Oligomers were added at 10-30 phr to BisGMA-UDMA-TEGDMA (5:3:2, BUT). 25 wt% silanated inorganic fillers were added. Commercial cement (Relyx Veneer, 3M-ESPE) was also evaluated with 10-20 phr of aromatic oligomer. Near-IR was used to follow methacrylate conversion (DC) and rate of polymerization (Rpmax). Mechanical properties were evaluated in three-point bending (ISO 4049) for flexural strength/modulus (FS/FM, and toughness), and notched specimens (ASTM Standard E399-90) for fracture toughness (KIC). Polymerization stress (PS) was measured on the Bioman. Volumetric shrinkage (VS, %) was measured with the bonded disk technique. Results were analyzed with ANOVA/Tukey's test (α=5%). In general terms, for BUT cements, conversion and mechanical properties in flexure increased for selected groups with the addition of thio-urethane oligomers. The aromatic versions resulted in greater FS/FM than aliphatic. Fracture toughness increased by two-fold in the experimental groups (from 1.17 ± 0.36 MPam(1/2) to around 3.23 ± 0.22 MPam(1/2)). Rpmax decreased with the addition of thio-urethanes, though the vitrification point was not statistically different from the control. VS and PS decreased with both oligomers. For the commercial cement, 20 phr of oligomer increased DC, vitrification, reduced Rpmax and also significantly increased KIC, and reduced PS and FM. Thio-urethane oligomers were shown to favorably modify conventional dimethacrylate networks. Significant reductions in polymerization stress were achieved at the same time conversion and fracture toughness increased. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
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Kazami, Nao; Sakaguchi, Masayoshi; Mizutani, Daisuke; Masuda, Tatsuhiko; Wakita, Satoshi; Oyama, Fumitaka; Kawakita, Masao; Sugahara, Yasusato
2015-11-05
Chitin oligomers are of interest because of their numerous biologically relevant properties. To prepare chitin oligomers containing 4-6 GlcNAc units [(GlcNAc)4-6], α- and β-chitin were hydrolyzed with concentrated hydrochloric acid at 40 °C. The reactant was mixed with acetone to recover the acetone-insoluble material, and (GlcNAc)4-6 was efficiently recovered after subsequent water extraction. Composition analysis using gel permeation chromatography and MALDI-TOF mass spectrometry indicated that (GlcNAc)4-6 could be isolated from the acetone-insoluble material with recoveries of approximately 17% and 21% from the starting α-chitin and β-chitin, respectively. The acetone precipitation method is highly useful for recovering chitin oligomers from the acid hydrolysate of chitin. The changes in the molecular size and higher-order structure of chitin during the course of hydrolysis were also analyzed, and a model that explains the process of oligomer accumulation is proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Synthesis and characterization of thermally stable oligomer-metal ...
African Journals Online (AJOL)
The thermal stabilities of the oligomer-metal complexes were compared by thermogravimetric (TG) and differential thermal (DTA) analyses. According to TG, oligomer-metal complexes were stable against to temperature and thermooxidative decomposition. The weight losses of oligomer-metal complexes were found to be 5 ...
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Characterization of methacrylate-based composites containing thio-urethane oligomers.
Bacchi, Atais; Nelson, Morgan; Pfeifer, Carmem S
2016-02-01
To evaluate the ability of thio-urethane oligomers to improve the properties of restorative composite resins. Oligomers were synthesized by combining 1,6-hexanediol-diissocyante (aliphatic) with pentaerythritol tetra-3-mercaptopropionate (PETMP) or 1,3-bis(1-isocyanato-1-methylethyl)benzene (aromatic) with trimethylol-tris-3-mercaptopropionate (TMP), at 1:2 isocyanate:thiol, leaving pendant thiols. Oligomers were added at 0-20 wt% to BisGMA-TEGDMA (70-30 wt%). Silanated inorganic fillers were added (70 wt%). Materials were photoactivated at 800 mW/cm(2) filtered to 320-500 nm. Near-IR was used to follow degree of methacrylate conversion (DC). Mechanical properties were evaluated in three-point bending with 2 mm × 2 mm × 25 mm bars for flexural strength/modulus and toughness (FS/E, and T) according to ISO 4049, and 2 mm × 5 mm × 25 mm notched specimens for fracture toughness (KIC). Polymerization stress (PS) was measured on the Bioman. Results were analyzed with ANOVA/Tukey's test (α=5%). Significant increase in DC was observed in thio-urethane-containing materials especially for the group with 20 wt% of aliphatic version. Materials composed by oligomers also promoted higher FS, E, and KIC in comparison to controls irrespective of thio-urethane type. A significant increase in toughness was detected by ANOVA, but not distinguished in the groups. The PS was significantly reduced by the presence of thio-urethane for almost all groups. The use of thio-urethane oligomer to compose methacrylate-based restorative composite promote increase in DC, FS, E and KIC while significant reduces PS. A simple additive was shown to reduce stress while increasing convrersion and mechanical properties, mainly fracture toughness. This has he potential of increasing the service life of dental composites, without changing current operatory procedures. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Rasool Suhail
2007-09-01
Full Text Available Abstract Background Amyloid-related degenerative diseases are associated with the accumulation of misfolded proteins as amyloid fibrils in tissue. In Alzheimer disease (AD, amyloid accumulates in several distinct types of insoluble plaque deposits, intracellular Aβ and as soluble oligomers and the relationships between these deposits and their pathological significance remains unclear. Conformation dependent antibodies have been reported that specifically recognize distinct assembly states of amyloids, including prefibrillar oligomers and fibrils. Results We immunized rabbits with a morphologically homogeneous population of Aβ42 fibrils. The resulting immune serum (OC specifically recognizes fibrils, but not random coil monomer or prefibrillar oligomers, indicating fibrils display a distinct conformation dependent epitope that is absent in prefibrillar oligomers. The fibril epitope is also displayed by fibrils of other types of amyloids, indicating that the epitope is a generic feature of the polypeptide backbone. The fibril specific antibody also recognizes 100,000 × G soluble fibrillar oligomers ranging in size from dimer to greater than 250 kDa on western blots. The fibrillar oligomers recognized by OC are immunologically distinct from prefibrillar oligomers recognized by A11, even though their sizes overlap broadly, indicating that size is not a reliable indicator of oligomer conformation. The immune response to prefibrillar oligomers and fibrils is not sequence specific and antisera of the same specificity are produced in response to immunization with islet amyloid polypeptide prefibrillar oligomer mimics and fibrils. The fibril specific antibodies stain all types of amyloid deposits in human AD brain. Diffuse amyloid deposits stain intensely with anti-fibril antibody although they are thioflavin S negative, suggesting that they are indeed fibrillar in conformation. OC also stains islet amyloid deposits in transgenic mouse models of type
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In vivo CHI3L1 (YKL-40 expression in astrocytes in acute and chronic neurological diseases
Directory of Open Access Journals (Sweden)
Hamilton Ronald L
2010-06-01
Full Text Available Abstract Background CHI3L1 (YKL-40 is up-regulated in a variety of inflammatory conditions and cancers. We have previously reported elevated CHI3L1 concentration in the cerebrospinal fluid (CSF of human and non-human primates with lentiviral encephalitis and using immunohistochemistry showed that CHI3L1 was associated with astrocytes. Methods In the current study CHI3L1 transcription and expression were evaluated in a variety of acute and chronic human neurological diseases. Results ELISA revealed significant elevation of CHI3L1 in the CSF of multiple sclerosis (MS patients as well as mild elevation with aging. In situ hybridization (ISH showed CHI3L1 transcription mostly associated with reactive astrocytes, that was more pronounced in inflammatory conditions like lentiviral encephalitis and MS. Comparison of CHI3L1 expression in different stages of brain infarction showed that YKL40 was abundantly expressed in astrocytes during acute phases and diminished to low levels in chronic infarcts. Conclusions Taken together, these findings demonstrate that CHI3L1 is induced in astrocytes in a variety of neurological diseases but that it is most abundantly associated with astrocytes in regions of inflammatory cells.
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Single-molecule studies of oligomer extraction and uptake of dyes in poly(dimethylsiloxane) films.
Lange, Jeffrey J; Collinson, Maryanne M; Culbertson, Christopher T; Higgins, Daniel A
2009-12-15
Single-molecule microscopic methods were used to probe the uptake, mobility, and entrapment of dye molecules in cured poly(dimethylsiloxane) (PDMS) films as a function of oligomer extraction. The results are relevant to the use of PDMS in microfluidic separations, pervaporation, solid-phase microextraction, and nanofiltration. PDMS films were prepared by spin-casting dilute solutions of Sylgard 184 onto glass coverslips, yielding approximately 1.4 microm thick films after curing. Residual oligomers were subsequently extracted from the films by "spin extraction". In this procedure, 200 microL aliquots of isopropyl alcohol were repeatedly dropped onto the film surface and spun off at 2000 rpm. Samples extracted 5, 10, 20, and 40 times were investigated. Dye molecules were loaded into these films by spin-casting nanomolar dye solutions onto the films. Both neutral perylene diimide (N,N'-bis(butoxypropyl)perylene-3,4,9,10-tetracarboxylic diimide) and cationic rhodamine 6G (R6G) dyes were employed. The films were imaged by confocal fluorescence microscopy. The images obtained depict nonzero populations of fixed and mobile molecules in all films. Cross-correlation methods were used to quantitatively determine the population of fixed molecules in a given region, while a Bayesian burst analysis was used to obtain the total population of molecules. The results show that the total amount of dye loaded increases with increased oligomer extraction, while the relative populations of fixed and mobile molecules decrease and increase, respectively. Bulk R6G data also show greater dye loading with increased oligomer extraction.
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Directory of Open Access Journals (Sweden)
Linn Wicklund
Full Text Available Cognitive impairment in Alzheimer's disease (AD patients is associated with a decline in the levels of growth factors, impairment of axonal transport and marked degeneration of basal forebrain cholinergic neurons (BFCNs. Neurogenesis persists in the adult human brain, and the stimulation of regenerative processes in the CNS is an attractive prospect for neuroreplacement therapy in neurodegenerative diseases such as AD. Currently, it is still not clear how the pathophysiological environment in the AD brain affects stem cell biology. Previous studies investigating the effects of the β-amyloid (Aβ peptide on neurogenesis have been inconclusive, since both neurogenic and neurotoxic effects on progenitor cell populations have been reported. In this study, we treated pluripotent human embryonic stem (hES cells with nerve growth factor (NGF as well as with fibrillar and oligomeric Aβ1-40 and Aβ1-42 (nM-µM concentrations and thereafter studied the differentiation in vitro during 28-35 days. The process applied real time quantitative PCR, immunocytochemistry as well as functional studies of intracellular calcium signaling. Treatment with NGF promoted the differentiation into functionally mature BFCNs. In comparison to untreated cells, oligomeric Aβ1-40 increased the number of functional neurons, whereas oligomeric Aβ1-42 suppressed the number of functional neurons. Interestingly, oligomeric Aβ exposure did not influence the number of hES cell-derived neurons compared with untreated cells, while in contrast fibrillar Aβ1-40 and Aβ1-42 induced gliogenesis. These findings indicate that Aβ1-42 oligomers may impair the function of stem cell-derived neurons. We propose that it may be possible for future AD therapies to promote the maturation of functional stem cell-derived neurons by altering the brain microenvironment with trophic support and by targeting different aggregation forms of Aβ.
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International Nuclear Information System (INIS)
Makoveichuk, Elena; Sukonina, Valentina; Kroupa, Olessia; Thulin, Petra; Ehrenborg, Ewa; Olivecrona, Thomas; Olivecrona, Gunilla
2012-01-01
Highlights: ► Lipoprotein lipase (LPL) activity is controlled by ANGPTL4 in THP-1 macrophages. ► Both LPL and ANGPTL4 bind to THP-1 macrophages in a heparin-releasable fashion. ► Only monomers of ANGPTL4 are present within THP-1 macrophages. ► Covalent oligomers of ANGPTL4 appear on cell surface and in medium. ► Inactivation of LPL coincide with ANGPTL4 oligomer formation on cell surfaces. -- Abstract: Lipoprotein lipase (LPL) hydrolyzes triglycerides in plasma lipoproteins causing release of fatty acids for metabolic purposes in muscles and adipose tissue. LPL in macrophages in the artery wall may, however, promote foam cell formation and atherosclerosis. Angiopoietin-like protein (ANGPTL) 4 inactivates LPL and ANGPTL4 expression is controlled by peroxisome proliferator-activated receptors (PPAR). The mechanisms for inactivation of LPL by ANGPTL4 was studied in THP-1 macrophages where active LPL is associated with cell surfaces in a heparin-releasable form, while LPL in the culture medium is mostly inactive. The PPARδ agonist GW501516 had no effect on LPL mRNA, but increased ANGPTL4 mRNA and caused a marked reduction of the heparin-releasable LPL activity concomitantly with accumulation of inactive, monomeric LPL in the medium. Intracellular ANGPTL4 was monomeric, while dimers and tetramers of ANGPTL4 were present in the heparin-releasable fraction and medium. GW501516 caused an increase in the amount of ANGPTL4 oligomers on the cell surface that paralleled the decrease in LPL activity. Actinomycin D blocked the effects of GW501516 on ANGPTL4 oligomer formation and prevented the inactivation of LPL. Antibodies against ANGPTL4 interfered with the inactivation of LPL. We conclude that inactivation of LPL in THP-1 macrophages primarily occurs on the cell surface where oligomers of ANGPTL4 are formed.
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Pina, João; de Melo, J Seixas; Breusov, D; Scherf, Ullrich
2013-09-28
A comprehensive spectral and photophysical investigation of four donor-acceptor-donor (DAD) oligomers consisting of electron-deficient 2,1,3-benzothiadiazole or quinoxaline moieties linked to electron-rich thienyl or bithienyl units has been undertaken. Additionally, a bis(dithienyl) substituted naphthalene was also investigated. The D-A-D nature of these oligomers resulted in the presence of an intramolecular charge transfer (ICT) state, which was further substantiated by solvatochromism studies (analysis with the Lippert-Mataga formalism). Hereby, significant differences have been obtained for the fluorescence quantum yields of the oligomers in the non-polar solvent methylcyclohexane vs. the polar ethanol. The study was further complemented with the determination of the optimized ground-state molecular geometries for the oligomers together with the prediction of the lowest vertical one-electron excitation energy and the relevant molecular orbital contours using DFT calculations. The electronic transitions show a clear HOMO to LUMO charge-transfer character. In contrast to the thiophene oligomers (the oligothiophenes with n = 1-7), where the intersystem crossing (ISC) yield decreases with n, the studied DAD oligomers were found to show an increase in the ISC efficiency with the number of (donor) thienyl units.
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Solvent free low-melt viscosity imide oligomers and thermosetting polymide composites
Chuang, Chun-Hua (Inventor)
2012-01-01
.[.This invention relates to the composition and a solvent-free process for preparing novel imide oligomers and polymers specifically formulated with effective amounts of a dianhydride such as 2,3,3',4-biphenyltetra carboxylic dianydride (a-BPDA), at least one aromatic diamine and an endcapped of 4-phenylethynylphthalic anhydride (PEPA) or nadic anhydride to produce imide oligomers that possess a low-melt viscosity of 1-60 poise at 260-280.degree. C. When the imide oligomer melt is cured at about 371.degree. C. in a press or autoclave under 100-500 psi, the melt resulted in a thermoset polyimide having a glass transition temperature (T.sub.g) equal to and above 310.degree. C. A novel feature of this process is that the monomers; namely the dianhydrides, diamines and the endcaps, are melt processable to form imide oligomers at temperatures ranging between 232-280.degree. C. (450-535.degree. F.) without any solvent. These low-melt imide oligomers can be easily processed by resin transfer molding (RTM), vacuum-assisted resin transfer molding (VARTM) or the resin infusion process with fiber preforms e.g. carbon, glass or quartz preforms to produce polyimide matrix composites with 288-343.degree. C. (550-650.degree. F.) high temperature performance capability..]. .Iadd.This invention relates to compositions and a solvent-free reaction process for preparing imide oligomers and polymers specifically derived from effective amounts of dianhydrides such as 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), at least one aromatic polyamine and an end-cap such as 4-phenylethynyphthalic anhydride (PEPA) or nadic anhydride to produce imide oligomers that possess a low-melt viscosity of 1-60 poise at 260.degree. C.-280.degree. C..Iaddend.
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Preparation of Stable Amyloid-β Oligomers Without Perturbative Methods.
Kotler, Samuel A; Ramamoorthy, Ayyalusamy
2018-01-01
Soluble amyloid-β (Aβ) oligomers have become a focal point in the study of Alzheimer's disease due to their ability to elicit cytotoxicity. A number of recent studies have concentrated on the structural characterization of soluble Aβ oligomers to gain insight into their mechanism of toxicity. Consequently, providing reproducible protocols for the preparation of such oligomers is of utmost importance. The method presented in this chapter details a protocol for preparing an Aβ oligomer, with a primarily disordered secondary structure, without the need for chemical modification or amino acid substitution. Due to the stability of these disordered Aβ oligomers and the reproducibility with which they form, they are amenable for biophysical and high-resolution structural characterization.
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Directory of Open Access Journals (Sweden)
Wei D Duan-Porter
Full Text Available Nucleophosmin (NPM1 is an abundant, nucleolar tumor antigen with important roles in cell proliferation and putative contributions to oncogenesis. Wild-type NPM1 forms pentameric oligomers through interactions at the amino-terminal core domain. A truncated form of NPM1 found in some hepatocellular carcinoma tissue formed an unusually stable oligomer and showed increased susceptibility to cleavage by granzyme B. Initiation of translation at the seventh methionine generated a protein (M7-NPM that shared all these properties. We used deuterium exchange mass spectrometry (DXMS to perform a detailed structural analysis of wild-type NPM1 and M7-NPM, and found dynamic conformational shifts or local "unfolding" at a specific monomer-monomer interface which included the β-hairpin "latch." We tested the importance of interactions at the β-hairpin "latch" by replacing a conserved tyrosine in the middle of the β-hairpin loop with glutamic acid, generating Y67E-NPM. Y67E-NPM did not form stable oligomers and further, prevented wild-type NPM1 oligomerization in a dominant-negative fashion, supporting the critical role of the β-hairpin "latch" in monomer-monomer interactions. Also, we show preferential cleavage by granzyme B at one of two available aspartates (either D161 or D122 in M7-NPM and Y67E-NPM, whereas wild-type NPM1 was cleaved at both sites. Thus, we observed a correlation between the propensity to form oligomers and granzyme B cleavage site selection in nucleophosmin proteins, suggesting that a small change at an important monomer-monomer interface can affect conformational shifts and impact protein-protein interactions.
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Carmona, D.; Rodriguez-Almazan, C.; Munoz-Garay, C.; Portugal, L.; Perez, C.; Maagd, de R.A.; Bakker, P.; Soberon, M.; Bravo, A.
2011-01-01
Background - Bacillus thuringiensis Cry toxins are used worldwide in the control of different insect pests important in agriculture or in human health. The Cry proteins are pore-forming toxins that affect the midgut cell of target insects. It was shown that non-toxic Cry1Ab helix a-4 mutants had a
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Structural and functional properties of prefibrillar α-synuclein oligomers.
Pieri, Laura; Madiona, Karine; Melki, Ronald
2016-04-14
The deposition of fibrillar alpha-synuclein (α-syn) within inclusions (Lewy bodies and Lewy neurites) in neurons and glial cells is a hallmark of synucleinopathies. α-syn populates a variety of assemblies ranging from prefibrillar oligomeric species to fibrils whose specific contribution to neurodegeneration is still unclear. Here, we compare the specific structural and biological properties of distinct soluble prefibrillar α-syn oligomers formed either spontaneously or in the presence of dopamine and glutaraldehyde. We show that both on-fibrillar assembly pathway and distinct dopamine-mediated and glutaraldehyde-cross-linked α-syn oligomers are only slightly effective in perturbing cell membrane integrity and inducing cytotoxicity, while mature fibrils exhibit the highest toxicity. In contrast to low-molecular weight and unstable oligomers, large stable α-syn oligomers seed the aggregation of soluble α-syn within reporter cells although to a lesser extent than mature α-syn fibrils. These oligomers appear elongated in shape. Our findings suggest that α-syn oligomers represent a continuum of species ranging from unstable low molecular weight particles to mature fibrils via stable elongated oligomers composed of more than 15 α-syn monomers that possess seeding capacity.
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Peptide oligomers for holographic data storage
DEFF Research Database (Denmark)
Berg, Rolf Henrik; Hvilsted, Søren; Ramanujam, P.S.
1996-01-01
SEVERAL classes of organic materials (such as photoanisotropic liquid-crystalline polymers(1-4) and photorefractive polymers(5-7)) are being investigated for the development of media for optical data storage. Here we describe a new family of organic materials-peptide oligomers containing azobenzene...
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Mitchell, Elizabeth O; Stewart, Greg; Bajzik, Olivier; Ferret, Mathieu; Bentsen, Christopher; Shriver, M Kathleen
2013-12-01
A multisite study was conducted to evaluate the performance of the Bio-Rad 4th generation GS HIV Combo Ag/Ab EIA versus Abbott 4th generation ARCHITECT HIV Ag/Ab Combo. The performance of two 3rd generation EIAs, Ortho Diagnostics Anti-HIV 1+2 EIA and Siemens HIV 1/O/2 was also evaluated. Study objective was comparison of analytical HIV-1 p24 antigen detection, sensitivity in HIV-1 seroconversion panels, specificity in blood donors and two HIV false reactive panels. Analytical sensitivity was evaluated with International HIV-1 p24 antigen standards, the AFFSAPS (pg/mL) and WHO 90/636 (IU/mL) standards; sensitivity in acute infection was compared on 55 seroconversion samples, and specificity was evaluated on 1000 negative blood donors and two false reactive panels. GS HIV Combo Ag/Ab demonstrated better analytical HIV antigen sensitivity compared to ARCHITECT HIV Ag/Ab Combo: 0.41 IU/mL versus 1.2 IU/mL (WHO) and 12.7 pg/mL versus 20.1 pg/mL (AFSSAPS); GS HIV Combo Ag/Ab EIA also demonstrated slightly better specificity compared to ARCHITECT HIV Ag/Ab Combo (100% versus 99.7%). The 4th generation HIV Combo tests detected seroconversion 7-11 days earlier than the 3rd generation HIV antibody only EIAs. Both 4th generation immunoassays demonstrated excellent performance in sensitivity, with the reduction of the serological window period (7-11 days earlier detection than the 3rd generation HIV tests). However, GS HIV Combo Ag/Ab demonstrated improved HIV antigen analytical sensitivity and slightly better specificity when compared to ARCHITECT HIV Ag/Ab Combo assay, with higher positive predictive values (PPV) for low prevalence populations. Copyright © 2013 Elsevier B.V. All rights reserved.
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International Nuclear Information System (INIS)
Gula, M.; Perleberg, O.; Gabel, D.
2000-01-01
The synthesis of two BSH derivatives is described, which can be used for oligomerization in DNA-synthesizers. Synthesis pathways lead to final products in five and six steps, respectively. Because of chirality interesting results were expected. NMR-measurements confirm this expectation. Possible oligomers with high concentrations of boron can be attached to biomolecules. These oligomers can be explored with several imaging methods (EELS, PEM) to determine the lower detection limit of boron with these methods. (author)
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Self-assembly of aniline oligomers
Czech Academy of Sciences Publication Activity Database
Zhao, Y.; Tomšík, Elena; Wang, J.; Morávková, Zuzana; Zhigunov, Alexander; Stejskal, Jaroslav; Trchová, Miroslava
2013-01-01
Roč. 8, č. 1 (2013), s. 129-137 ISSN 1861-4728 R&D Projects: GA ČR GA202/09/1626; GA ČR GAP205/12/0911 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : morphology * oligoaniline * oligomers Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.935, year: 2013
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International Nuclear Information System (INIS)
Tang Lin; Zhuang Yumei; Zhou Zhaohua; Yu Gehua; Pan Jianzhong; Zhang Xueguang
2002-01-01
Objective: To study the expression of CD 40 molecule and the biological effects mediated by CD 40 molecules on malignant B cells. Methods: Agonistic anti-human CD 40 monoclonal antibody (clone 5C11) was added to cell culture system. Cell counting, PI staining, Annexin-V staining and flow cytometric analysis were used to study the behavior of malignant B cell lines after treatment with mAb clone 5C11. Results: 5C11 induced homotypic aggregation and proliferation arrest and mediated apoptosis in multiple myeloma cell line XG2 that expressed CD 40 strongly; 5C11 induced B lymphoma cell line Daudi homotypic aggregation and proliferation arrest and apoptosis, the apoptosis of XG2 and Daudi by CD40 activation was not mediated by TNF. Conclusion: Agonistic anti-CD 40 mAb 5C11 can inhibit the proliferation of malignant B cells by inducing them to die apoplectically
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Energy Technology Data Exchange (ETDEWEB)
Makoveichuk, Elena; Sukonina, Valentina; Kroupa, Olessia [Department of Medical Biosciences, Physiological Chemistry Umea University, SE-901 87 Umea (Sweden); Thulin, Petra; Ehrenborg, Ewa [Atherosclerosis Research Unit, Department of Medicine, Karolinska Institutet, SE-171 76 Stockholm (Sweden); Olivecrona, Thomas [Department of Medical Biosciences, Physiological Chemistry Umea University, SE-901 87 Umea (Sweden); Olivecrona, Gunilla, E-mail: Gunilla.Olivecrona@medbio.umu.se [Department of Medical Biosciences, Physiological Chemistry Umea University, SE-901 87 Umea (Sweden)
2012-08-24
Highlights: Black-Right-Pointing-Pointer Lipoprotein lipase (LPL) activity is controlled by ANGPTL4 in THP-1 macrophages. Black-Right-Pointing-Pointer Both LPL and ANGPTL4 bind to THP-1 macrophages in a heparin-releasable fashion. Black-Right-Pointing-Pointer Only monomers of ANGPTL4 are present within THP-1 macrophages. Black-Right-Pointing-Pointer Covalent oligomers of ANGPTL4 appear on cell surface and in medium. Black-Right-Pointing-Pointer Inactivation of LPL coincide with ANGPTL4 oligomer formation on cell surfaces. -- Abstract: Lipoprotein lipase (LPL) hydrolyzes triglycerides in plasma lipoproteins causing release of fatty acids for metabolic purposes in muscles and adipose tissue. LPL in macrophages in the artery wall may, however, promote foam cell formation and atherosclerosis. Angiopoietin-like protein (ANGPTL) 4 inactivates LPL and ANGPTL4 expression is controlled by peroxisome proliferator-activated receptors (PPAR). The mechanisms for inactivation of LPL by ANGPTL4 was studied in THP-1 macrophages where active LPL is associated with cell surfaces in a heparin-releasable form, while LPL in the culture medium is mostly inactive. The PPAR{delta} agonist GW501516 had no effect on LPL mRNA, but increased ANGPTL4 mRNA and caused a marked reduction of the heparin-releasable LPL activity concomitantly with accumulation of inactive, monomeric LPL in the medium. Intracellular ANGPTL4 was monomeric, while dimers and tetramers of ANGPTL4 were present in the heparin-releasable fraction and medium. GW501516 caused an increase in the amount of ANGPTL4 oligomers on the cell surface that paralleled the decrease in LPL activity. Actinomycin D blocked the effects of GW501516 on ANGPTL4 oligomer formation and prevented the inactivation of LPL. Antibodies against ANGPTL4 interfered with the inactivation of LPL. We conclude that inactivation of LPL in THP-1 macrophages primarily occurs on the cell surface where oligomers of ANGPTL4 are formed.
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International Nuclear Information System (INIS)
Luo, Shenglian; Xu, Xiangli; Zhou, Guiyin; Liu, Chengbin; Tang, Yanhong; Liu, Yutang
2014-01-01
Graphical abstract: A high performance sorbent, oligomer-linked graphene oxide, was prepared by using oligomeric poly3-aminopropyltriethoxysilane as crosslinking agents. The sorbent could selectively remove Pb(II) with high adsorption capacity. - Highlights: • Oligomer-linked graphene oxide sharply fattened function groups. • The sorbent exhibited high adsorption capacity toward Pb(II). • Pb, Cu and Fe were selectively removed from smelter industrial effluent. • The sorption could be conducted at a wide pH range of about 4.0–7.0. - Abstract: A high performance sorbent, oligomer-linked graphene oxide (GO) composite, was prepared through simple cross-linking reactions between GO sheets and poly3-aminopropyltriethoxysilane (PAS) oligomers as crosslinking agents. The three-dimensional PAS oligomers prevented GO sheets from aggregation, provided foreign molecules with easier access, and introduced a large amount of amino functional groups. The morphology, structure and property of the PAS-GO composite were determined by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourie transform infrared (FTIR), X-ray diffractometer (XRD), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The adsorption performance of PAS-GO was investigated in removing Pb(II) ions from water. Compared to 3-aminopropyltriethoxysilane functionalized GO (AS-GO) which was prepared by the direct reaction between 3-aminopropyltriethoxysilane and GO, PAS-GO exhibited much higher adsorptivity toward Pb(II) with the maximum adsorption capacity of 312.5 mg/g at 303 K and furthermore the maximum adsorption capacity increased with increasing temperature. The adsorption could be conducted in a wide pH range of 4.0–7.0. Importantly, PAS-GO had a priority tendency to adsorb Pb, Cu and Fe from a mixed solution of metal ions, especially from a practical industrial effluent
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Luo, Lanxin; Cui, Yan; Cheng, Jinhui; Fang, Bairui; Wei, Zongmin; Sun, Baoshan
2018-08-01
To develop an efficient method for degradation of grape seed and skin proanthocyanidins polymers into oligomers, an optimized sulphurous acid degradation conditions for grape seed with the temperature of 60 °C, reaction time of 60 min and sample-sulphurous acid ratio of 1:0.2, and for grape skin with the temperature of 40 °C, reaction time of 60 min and sample-sulphurous acid ratio of 1:0.2, were established. Afterwards, HSCCC and prep-HPLC were used to fractionate and isolate individual proanthocyanidin oligomers from the degradation products. Total of ten dimeric or trimeric procyanidins were obtained, and most of them presented high yield (from 0.7 mg to 13.6 mg per run in grape seed and from 0.5 mg to 4.1 mg per run in grape skin) and high purity (over 90%). The proposed method provides a new way for large preparation of oligomeric proanthocyanidins from naturally abundant and wasted polymeric ones. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Electrografting of conductive oligomers and polymers using diazonium electroreduction
International Nuclear Information System (INIS)
Lacroix, Jean Christophe; Trippe-Allard, Gaelle; Ghilane, Jalal; Martin, Pascal
2014-01-01
This paper describes the attachment of conjugated oligomers onto electrode surface through the reduction of diazonium compounds. In this connection some properties of conjugated oligomers and of layers grafted through diazonium electroreduction will first be briefly presented. The electrochemical behavior of conjugated oligomers grafted on a surface using diazonium electroreduction will then be discussed. (paper)
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Electrografting of conductive oligomers and polymers using diazonium electroreduction
Lacroix, Jean Christophe; Trippe-Allard, Gaelle; Ghilane, Jalal; Martin, Pascal
2014-03-01
This paper describes the attachment of conjugated oligomers onto electrode surface through the reduction of diazonium compounds. In this connection some properties of conjugated oligomers and of layers grafted through diazonium electroreduction will first be briefly presented. The electrochemical behavior of conjugated oligomers grafted on a surface using diazonium electroreduction will then be discussed.
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CRY 1AB trangenic cowpea obtained by nodal electroporation ...
African Journals Online (AJOL)
Electroporation-mediated genetic transformation was used to introduce Cry 1 Ab insecticidal gene into cowpea. Nodal buds were electroporated in planta with a plasmid carrying the Cry 1Ab and antibiotic resistance npt II genes driven by a 35S CaMV promoter. T1 seeds derived from electroporated branches were selected ...
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Tau Oligomers as Pathogenic Seeds: Preparation and Propagation In Vitro and In Vivo.
Gerson, Julia E; Sengupta, Urmi; Kayed, Rakez
2017-01-01
Tau oligomers have been shown to be the main toxic tau species in a number of neurodegenerative disorders. In order to study tau oligomers both in vitro and in vivo, we have established methods for the reliable preparation, isolation, and detection of tau oligomers. Methods for the seeding of tau oligomers, isolation of tau oligomers from tissue, and detection of tau oligomers using tau oligomer-specific antibodies by biochemical and immunohistochemical methods are detailed below.
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Electron beam curing polyurethane acrylate oligomer in air
International Nuclear Information System (INIS)
Zhu, Zhenkang; Chen, Xing; Zhou, Jichun; Ma, Zue-Teh
1988-01-01
It has been found according to our synthesis that a novel kind of polyurethane acrylate oligomer can be cured by electron beam in the presence of oxygen, even at normal atomospheric levels, without any additives. Irradiation of the oligomer with substantially complete cure to a solid non-tacky state is quite remarkable. It has the same gel content (90 %) in air as in nitrogen at dose of 33 kGy. Double bond conversion of the oligomer is about 50 % by I.R. (author)
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International Nuclear Information System (INIS)
Ferro-Flores, Guillermina; Pimentel-Gonzalez, Gilmara; Gonzalez-Zavala, Maria Antonia; Murphy, Consuelo Arteaga de; Melendez-Alafort, Laura; Tendilla, Jose I.; Croft, Barbara Y.
1999-01-01
The biotinylated monoclonal antibody (MoAb) ior cea1 and its F(ab') 2 fragments were labeled with Re-188 by combination of avidin-biotin strategy. 188 Re-MoAb, 188 Re-MoAb-biotin, 188 Re-F(ab') 2 , and 188 Re-F(ab') 2 -biotin preparations were produced for these studies with specific activities of 1.30±0.18 GBq/mg and from instant freeze-dried kit formulations using ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) as a weak competing ligand. There were no significant differences (p>0.05) between the biodistribution in mice of biotinylated and unbiotinylated 188 Re-labeled immunoconjugates. When avidin was injected as a chase after injection of 188 Re-MoAb-biotin or 188 Re-F(ab') 2 -biotin, the blood radioactivity level decreased approximately 75% (cumulated activity) and the effective dose decreased almost 25% with respect to that of the radioimmunoconjugates in which the chase effect was not used. Our results suggest that 188 Re-labeled biotinylated MoAb ior cea1 and its F(ab') 2 fragments prepared by this method are stable complexes in vivo
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Solvent Free Low-Melt Viscosity Imide Oligomers And Thermosetting Polyimide Composites
Chuang, CHun-Hua (Inventor)
2006-01-01
This invention relates to the composition and a solvent-free process for preparing novel imide oligomers and polymers specifically formulated with effective amounts of a dianhydride such as 2,3,3',4-biphenyltetra carboxylic dianydride (a-BPDA), at least one aromatic diamine' and an endcapped of 4-phenylethynylphthalic anhydride (PEPA) or nadic anhydride to produce imide oligomers that possess a low-melt viscosity of 1-60 poise at 260-280" C. When the imide oligomer melt is cured at about 371 C. in a press or autoclave under 100-500 psi, the melt resulted in a thermoset polyimide having a glass transition temperature (T(sub g)) equal to and above 310 C. A novel feature of this process is that the monomers; namely the dianhydrides, diamines and the endcaps, are melt processable to form imide oligomers at temperatures ranging between 232-280 C. (450-535 F) without any solvent. These low-melt imide oligomers can be easily processed by resin transfer molding (RTM), vacuum-assisted resin transfer molding (VARTM) or the resin infusion process with fiber preforms e.g. carbon, glass or quartz preforms to produce polyimide matrix composites with 288-343C (550-650 F) high temperature performance capability.
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Expression of Cry1Ab and Cry2Ab by a polycistronic transgene with a self-cleavage peptide in rice.
Directory of Open Access Journals (Sweden)
Qichao Zhao
Full Text Available Insect resistance to Bacillus thuringiensis (Bt crystal protein is a major threat to the long-term use of transgenic Bt crops. Gene stacking is a readily deployable strategy to delay the development of insect resistance while it may also broaden insecticidal spectrum. Here, we report the creation of transgenic rice expressing discrete Cry1Ab and Cry2Ab simultaneously from a single expression cassette using 2A self-cleaving peptides, which are autonomous elements from virus guiding the polycistronic viral gene expression in eukaryotes. The synthetic coding sequences of Cry1Ab and Cry2Ab, linked by the coding sequence of a 2A peptide from either foot and mouth disease virus or porcine teschovirus-1, regardless of order, were all expressed as discrete Cry1Ab and Cry2Ab at high levels in the transgenic rice. Insect bioassays demonstrated that the transgenic plants were highly resistant to lepidopteran pests. This study suggested that 2A peptide can be utilized to express multiple Bt genes at high levels in transgenic crops.
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Pigments and oligomers for inks - moving towards the best combination
International Nuclear Information System (INIS)
Hutchinson, I.; Smith, S.; Grierson, W.; Devine, E.
1999-01-01
The formulation of UV curable printing inks depends on several complex factors. If the individual components of the ink are not complementary, then performance problems can arise. One critical combination is that between the pigment and the oligomer. In a new approach to improve understanding of pigment/oligomer interactions, the resources of a pigment manufacturer and an oligomer manufacturer have been combined to investigate the problem. Initial screening of process yellow pigments and several oligomer types highlighted performance variations which were then examined in more detail
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Lau, Ching-Shuan; Clausen, Edgar C; Lay, Jackson O; Gidden, Jennifer; Carrier, Danielle Julie
2013-01-01
Xylose oligomers are the intermediate products of xylan depolymerization into xylose monomers. An understanding of xylan depolymerization kinetics is important to improve the conversion of xylan into monomeric xylose and to minimize the formation of inhibitory products, thereby reducing ethanol production costs. The study of xylan depolymerization requires copious amount of xylose oligomers, which are expensive if acquired commercially. Our approach consisted of producing in-house oligomer material. To this end, birchwood xylan was used as the starting material and hydrolyzed in hot water at 200 °C for 60 min with a 4 % solids loading. The mixture of xylose oligomers was subsequently fractionated by a centrifugal partition chromatography (CPC) with a solvent system of butanol:methanol:water in a 5:1:4 volumetric ratio. Operating in an ascending mode, the butanol-rich upper phase (the mobile phase) eluted xylose oligomers from the water-rich stationary phase at a 4.89 mL/min flow rate for a total fractionation time of 300 min. The elution of xylose oligomers occurred between 110 and 280 min. The yields and purities of xylobiose (DP 2), xylotriose (DP 3), xylotetraose (DP 4), and xylopentaose (DP 5) were 21, 10, 14, and 15 mg/g xylan and 95, 90, 89, and 68 %, respectively. The purities of xylose oligomers from this solvent system were higher than those reported previously using tetrahydrofuran:dimethyl sulfoxide:water in a 6:1:3 volumetric ratio. Moreover, the butanol-based solvent system improved overall procedures by facilitating the evaporation of the solvents from the CPC fractions, rendering the purification process more efficient.
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Identification of Bacillus thuringiensis Cry1AbMod binding-proteins from Spodoptera frugiperda.
Martínez de Castro, Diana L; García-Gómez, Blanca I; Gómez, Isabel; Bravo, Alejandra; Soberón, Mario
2017-12-01
Bacillus thuringiensis Cry toxins are currently used for pest control in transgenic crops but evolution of resistance by the insect pests threatens the use of this technology. The Cry1AbMod toxin was engineered to lack the alpha helix-1 of the parental Cry1Ab toxin and was shown to counter resistance to Cry1Ab and Cry1Ac toxins in different insect species including the fall armyworm Spodoptera frugiperda. In addition, Cry1AbMod showed enhanced toxicity to Cry1Ab-susceptible S. frugiperda populations. To gain insights into the mechanisms of this Cry1AbMod-enhanced toxicity, we isolated the Cry1AbMod toxin binding proteins from S. frugiperda brush border membrane vesicles (BBMV), which were identified by pull-down assay and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The LC-MS/MS results indicated that Cry1AbMod toxin could bind to four classes of aminopeptidase (N1, N3, N4 y N5) and actin, with the highest amino acid sequence coverage acquired for APN 1 and APN4. In addition to these proteins, we found other proteins not previously described as Cry toxin binding proteins. This is the first report that suggests the interaction between Cry1AbMod and APN in S. frugiperda. Copyright © 2017 Elsevier Inc. All rights reserved.
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Multicolored, Low-Voltage-Driven, Flexible Organic Electrochromic Devices Based on Oligomers.
Wan, Zhijun; Zeng, Jinming; Li, Hui; Liu, Ping; Deng, Wenji
2018-04-20
In this study, a series of organic conjugated oligomers containing 3,4-ethylenedioxythiophene (EDOT) and aromatic groups are synthesized, which are as follows: 2,5-di(methyl benzoate)-3,4-ethylenedioxy-thiophene (1EDOT-2B-COOCH 3 ), 5,5'-di(methyl benzoate)-2,2'-bi(3,4-ethylenedioxythiophene) (2EDOT-2B-COOCH 3 ), 5,5″-di(methyl benzoate)-2,2':5',2″-ter(3,4-ethylenedioxythiophene) (3EDOT-2B-COOCH 3 ), and 5,5″'-di(methyl benzoate)-2,2':5',2″: 5″,2″'-quater(3,4-ethylenedioxythiophene) (4EDOT-2B-COOCH 3 ). Using these oligomers as active materials, flexible organic electrochromic devices are fabricated. The device structure is indium tin oxide-PET plastic slide (ITO-PET)/active layer/conducting gel/ITO-PET, and the electrochromic properties of oligomers are investigated. These oligomers exhibit reversible color changes upon electrochemical doping and dedoping. The highest optical contrast is exhibited by 4EDOT-2B-COOCH 3 , which is 75.2% at 700 nm. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Amyloid oligomer structure characterization from simulations: A general method
Energy Technology Data Exchange (ETDEWEB)
Nguyen, Phuong H., E-mail: phuong.nguyen@ibpc.fr [Laboratoire de Biochimie Théorique, UPR 9080, CNRS Université Denis Diderot, Sorbonne Paris Cité IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France); Li, Mai Suan [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Derreumaux, Philippe, E-mail: philippe.derreumaux@ibpc.fr [Laboratoire de Biochimie Théorique, UPR 9080, CNRS Université Denis Diderot, Sorbonne Paris Cité IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France); Institut Universitaire de France, 103 Bvd Saint-Germain, 75005 Paris (France)
2014-03-07
Amyloid oligomers and plaques are composed of multiple chemically identical proteins. Therefore, one of the first fundamental problems in the characterization of structures from simulations is the treatment of the degeneracy, i.e., the permutation of the molecules. Second, the intramolecular and intermolecular degrees of freedom of the various molecules must be taken into account. Currently, the well-known dihedral principal component analysis method only considers the intramolecular degrees of freedom, and other methods employing collective variables can only describe intermolecular degrees of freedom at the global level. With this in mind, we propose a general method that identifies all the structures accurately. The basis idea is that the intramolecular and intermolecular states are described in terms of combinations of single-molecule and double-molecule states, respectively, and the overall structures of oligomers are the product basis of the intramolecular and intermolecular states. This way, the degeneracy is automatically avoided. The method is illustrated on the conformational ensemble of the tetramer of the Alzheimer's peptide Aβ{sub 9−40}, resulting from two atomistic molecular dynamics simulations in explicit solvent, each of 200 ns, starting from two distinct structures.
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Binding Sites for Amyloid-β Oligomers and Synaptic Toxicity
Smith, Levi M.; Strittmatter, Stephen M.
2017-01-01
In Alzheimer’s disease (AD), insoluble and fibrillary amyloid-β (Aβ) peptide accumulates in plaques. However, soluble Aβ oligomers are most potent in creating synaptic dysfunction and loss. Therefore, receptors for Aβ oligomers are hypothesized to be the first step in a neuronal cascade leading to dementia. A number of cell-surface proteins have been described as Aβ binding proteins, and one or more are likely to mediate Aβ oligomer toxicity in AD. Cellular prion protein (PrPC) is a high-affinity Aβ oligomer binding site, and a range of data delineates a signaling pathway leading from Aβ complexation with PrPC to neuronal impairment. Further study of Aβ binding proteins will define the molecular basis of this crucial step in AD pathogenesis. PMID:27940601
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Isolation and Characterization of a Virulent Bacteriophage AB1 of Acinetobacter baumannii
Directory of Open Access Journals (Sweden)
Jia Shiru
2010-04-01
Full Text Available Abstract Background Acinetobacter baumannii is an emerging nosocomial pathogen worldwide with increasing prevalence of multi-drug and pan-drug resistance. A. baumannii exists widely in natural environment, especially in health care settings, and has been shown difficult to be eradicated. Bacteriophages are often considered alternative agent for controlling bacterial infection and contamination. In this study, we described the isolation and characterization of one virulent bacteriophage AB1 capable of specifically infecting A. baumannii. Results A virulent bacteriophage AB1, specific for infecting a clinical strain A. baumannii KD311, was first isolated from marine sediment sample. Restriction analysis indicated that phage AB1 was a dsDNA virus with an approximate genome size of 45.2 kb to 46.9 kb. Transmission electron microscopy showed that phage AB1 had an icosahedral head with a non-contractile tail and collar or whisker structures, and might be tentatively classified as a member of the Siphoviridae family. Proteomic pattern of phage AB1, generated by SDS-PAGE using purified phage particles, revealed five major bands and six minor bands with molecular weight ranging from 14 to 80 kilo-dalton. Also determined was the adsorption rate of phage AB1 to the host bacterium, which was significantly enhanced by addition of 10 mM CaCl2. In a single step growth test, phage AB1 was shown having a latent period of 18 minutes and a burst size of 409. Moreover, pH and thermal stability of phage AB1 were also investigated. At the optimal pH 6.0, 73.2% of phages survived after 60 min incubation at 50°C. When phage AB1 was used to infect four additional clinical isolates of A. baumannii, one clinical isolate of Stenotrophomonas maltophilia, and Pseudomonas aeruginosa lab strains PAK and PAO1, none of the tested strains was found susceptible, indicating a relatively narrow host range for phage AB1. Conclusion Phage AB1 was capable of eliciting efficient lysis
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Directory of Open Access Journals (Sweden)
Bidyut eSarkar
2013-04-01
Full Text Available Amyloid beta (Aβ is an extracellular 39-43 residue long peptide present in the mammalian cerebrospinal fluid, whose aggregation is associated with Alzheimer’s disease. Small oligomers of Aβ are currently thought to be the key to toxicity. However, it is not clear why the monomers of Aβ are non-toxic, and at what stage of aggregation toxicity emerges. Interactions of Aβ with cell membranes is thought to be the initiator of toxicity, but membrane-binding studies with different preparations of monomers and oligomers have not settled this issue. We have earlier found that thermodynamically stable Aβ monomers emerge spontaneously from oligomeric mixtures upon long term incubation in physiological solutions (Nag et al, JBC, 2011. Here we show that the membrane-affinity of these stable Aβ monomers is much lower than that of a mixture of small oligomers (containing dimers to decamers, providing a clue to the emergence of toxicity. Fluorescently labeled Aβ40 monomers show negligible binding to cell membranes of a neuronal cell line (RN46A at physiological concentrations (250 nM, while oligomers at the same concentrations show strong binding within 30 minutes of incubation. The increased affinity most likely does not require any specific neuronal receptor, since this difference in membrane-affinity was also observed in a somatic cell-line (HEK 293T. Similar results are also obtained for Aβ42 monomers and oligomers. Minimal amount of cell death is observed at these concentrations even after 36 hours of incubation. It is likely that membrane binding precedes subsequent slower toxic events induced by Aβ. Our results a provide an explanation for the non-toxic nature of Aβ monomers, b suggest that Aβ toxicity emerges at the initial oligomeric phase, and c provide a quick assay for monitoring the benign-to-toxic transformation of Aβ.
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α-Synuclein oligomers induced by docosahexaenoic acid affect membrane integrity.
Directory of Open Access Journals (Sweden)
Chiara Fecchio
Full Text Available A key feature of Parkinson disease is the aggregation of α-synuclein and its intracellular deposition in fibrillar form. Increasing evidence suggests that the pathogenicity of α-synuclein is correlated with the activity of oligomers formed in the early stages of its aggregation process. Oligomers toxicity seems to be associated with both their ability to bind and affect the integrity of lipid membranes. Previously, we demonstrated that α-synuclein forms oligomeric species in the presence of docosahexaenoic acid and that these species are toxic to cells. Here we studied how interaction of these oligomers with membranes results in cell toxicity, using cellular membrane-mimetic and cell model systems. We found that α-synuclein oligomers are able to interact with large and small unilamellar negatively charged vesicles acquiring an increased amount of α-helical structure, which induces small molecules release. We explored the possibility that oligomers effects on membranes could be due to pore formation, to a detergent-like effect or to fibril growth on the membrane. Our biophysical and cellular findings are consistent with a model where α-synuclein oligomers are embedded into the lipid bilayer causing transient alteration of membrane permeability.
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Patel, Yogesh S
2014-01-01
Novel oligomer metal complexes (2a-f) of the ligand 2,5-bis((4-bromophenyl)carbamoyl) terephthalic acid (1) were prepared using transition metal salts and characterized by various spectroscopic techniques. The geometry of oligomer metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. Polymeric properties have also been carried out. Ligand was synthesized using pyromellitic dianhydride and 4-bromoaniline. It was duly characterized. All novel synthesized compounds 1 and 2a-f were evaluated for their antibacterial and antifungal activity. The results showed significantly higher antibacterial and antifungal activity of oligomer metal complexes compared to the ligand.
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Lim, Jieyan; Sana, Barindra; Krishnan, Ranganathan; Seayad, Jayasree; Ghadessy, Farid J; Jana, Satyasankar; Ramalingam, Balamurugan
2018-02-02
The laccase-catalyzed oxidative polymerization of monomeric and dimeric lignin model compounds was carried out with oxygen as the oxidant in aqueous medium. The oligomers were characterized by using gel permeation chromatography (GPC) and matrix-assisted laser desorption ionization time-of-flight mass spectroscopy (MALDI-TOF MS) analysis. Oxidative polymerization led to the formation of oligomeric species with a number-average molecular weight (M n ) that ranged from 700 to 2300 Da with a low polydispersity index. Spectroscopic analysis provided insight into the possible modes of linkages present in the oligomers, and the oligomerization is likely to proceed through the formation of C-C linkages between phenolic aromatic rings. The oligomers were found to show good UV light absorption characteristics with high molar extinction coefficient (5000-38 000 m -1 cm -1 ) in the UV spectral region. The oligomers were blended independently with polyvinyl chloride (PVC) by using solution blending to evaluate the compatibility and UV protection ability of the oligomers. The UV/Vis transmittance spectra of the oligomer-embedded PVC films indicated that these lignin-like oligomers possessed a notable ability to block UV light. In particular, oligomers obtained from vanillyl alcohol and the dimeric lignin model were found to show good photostability in accelerated UV weathering experiments. The UV-blocking characteristics and photostability were finally compared with the commercial low-molecular-weight UV stabilizer 2,4-dihydroxybenzophenone. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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International Nuclear Information System (INIS)
Wu Dianxing; Ye Qingfu; Wang Zhonghua; Xia Yingwu
2004-01-01
The effects of gamma irradiation on the transgenic rice containing a synthetic cry1Ab gene from Bacillus thuringiensis were investigated. There was almost no difference in the content of the major nutritional components, i.e. crude protein, crude lipid, eight essential amino acids and total ash between the irradiated grains and the non-irradiated transgenic rice. However, the amounts of Cry1Ab protein and apparent amylose in the irradiated transgenic rice were reduced significantly by the doses higher than 200 Gy. In vivo observation showed that Cry1Ab protein contents also decreased in the fresh leaf tissues of survival seedlings after irradiation with 200 Gy or higher doses and showed inhibition of seedling growth. The results indicate that gamma irradiation might improve the quality of transgenic rice due to removal of the toxic Cry1Ab protein
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Effect of Conjugation Length on Photoinduced Charge-Transfer in π-Conjugated Oligomer-Acceptor Dyads
Jiang, Junlin
2017-05-25
A series of -conjugated oligomer-acceptor dyads were synthesized that feature oligo(phenylene ethynylene) (OPE) conjugated backbones end-capped with a naphthalene diimide (NDI) acceptor. The OPE segments vary in length from 4 to 8 phenylene ethynene units (PEn-NDI, where n = 4, 6 and 8). Fluorescence and transient absorption spectroscopy reveals that intramolecular OPE NDI charge transfer dominates the deactivation of excited states of the PEn-NDI oligomers. Both charge separation (CS) and charge recombination (CR) are strongly exothermic (G0CS ~ -1.1 and G0CR ~ -2.0 eV), and the driving forces do not vary much across the series because the oxidation and reduction potentials and singlet energies of the OPEs do not vary much with their length. Bimolecular photoinduced charge transfer between model OPEs that do not contain the NDI acceptors with methyl viologen was studied, and the results reveal that the absorption of the cation radical state (OPE+•) remains approximately constant ( ~ 575 nm) regardless of oligomer length. This finding suggests that the cation radical (polaron) of the OPE is relatively localized, effectively occupying a confined segment of n 4 repeat units in the longer oligomers. Photoinduced intramolecular electron transfer dynamics in the PEn-NDI series was investigated by UV-visible femtosecond transient absorption spectroscopy with visible and mid-infrared probes. Charge separation occurs on the 1 – 10 ps timescale, with the rates decreasing slightly with increased oligomer length (βCS ~ 0.15 Å-1). The rate for charge-recombination decreases in the sequence PE4-NDI > PE6-NDI ~ PE8-NDI. The discontinuous distance dependence in the rate for charge recombination may be related to the spatial localization of the positive polaron state in the longer oligomers.
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Effect of Conjugation Length on Photoinduced Charge-Transfer in π-Conjugated Oligomer-Acceptor Dyads
Jiang, Junlin; Alsam, Amani Abdu; Wang, Shanshan; Aly, Shawkat Mohammede; Pan, Zhenxing; Mohammed, Omar F.; Schanze, Kirk S.
2017-01-01
A series of -conjugated oligomer-acceptor dyads were synthesized that feature oligo(phenylene ethynylene) (OPE) conjugated backbones end-capped with a naphthalene diimide (NDI) acceptor. The OPE segments vary in length from 4 to 8 phenylene ethynene units (PEn-NDI, where n = 4, 6 and 8). Fluorescence and transient absorption spectroscopy reveals that intramolecular OPE NDI charge transfer dominates the deactivation of excited states of the PEn-NDI oligomers. Both charge separation (CS) and charge recombination (CR) are strongly exothermic (G0CS ~ -1.1 and G0CR ~ -2.0 eV), and the driving forces do not vary much across the series because the oxidation and reduction potentials and singlet energies of the OPEs do not vary much with their length. Bimolecular photoinduced charge transfer between model OPEs that do not contain the NDI acceptors with methyl viologen was studied, and the results reveal that the absorption of the cation radical state (OPE+•) remains approximately constant ( ~ 575 nm) regardless of oligomer length. This finding suggests that the cation radical (polaron) of the OPE is relatively localized, effectively occupying a confined segment of n 4 repeat units in the longer oligomers. Photoinduced intramolecular electron transfer dynamics in the PEn-NDI series was investigated by UV-visible femtosecond transient absorption spectroscopy with visible and mid-infrared probes. Charge separation occurs on the 1 – 10 ps timescale, with the rates decreasing slightly with increased oligomer length (βCS ~ 0.15 Å-1). The rate for charge-recombination decreases in the sequence PE4-NDI > PE6-NDI ~ PE8-NDI. The discontinuous distance dependence in the rate for charge recombination may be related to the spatial localization of the positive polaron state in the longer oligomers.
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Yu, Han; Li, Weili; Tian, Hongkun; Wang, Haibo; Yan, Donghang; Zhang, Jingping; Geng, Yanhou; Wang, Fosong
2014-04-09
Two benzothienobenzothiophene (BTBT)-based conjugated oligomers, i.e., 2,2'-bi[1]benzothieno[3,2-b][1]benzothiophene (1) and 5,5'-bis([1]benzothieno[3,2-b][1]benzothiophen-2-yl)-2,2'-bithiophene (2), were prepared and characterized. Both oligomers exhibit excellent thermal stability, with 5% weight-loss temperatures (T(L)) above 370 °C; no phase transition was observed before decomposition. The highest occupied molecular orbital (HOMO) levels of 1 and 2 are -5.3 and -4.9 eV, respectively, as measured by ultraviolet photoelectron spectroscopy. Thin-film X-ray diffraction and atomic force microscopy characterizations indicate that both oligomers form highly crystalline films with large domain sizes on octadecyltrimethoxysilane-modified substrates. Organic thin-film transistors with top-contact and bottom-gate geometry based on 1 and 2 exhibited mobilities up to 2.12 cm(2)/V·s for 1 and 1.39 cm(2)/V·s for 2 in an ambient atmosphere. 1-based devices exhibited great air and thermal stabilities, as evidenced by the slight performance degradation after 2 months of storage under ambient conditions and after thermal annealing at temperatures below 250 °C.
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DEFF Research Database (Denmark)
Bless, N M; Huber-Lang, M; Guo, R F
2000-01-01
The role of the CC chemokines, macrophage inflammatory protein-1 beta (MIP-1 beta), monocyte chemotactic peptide-1 (MCP-1), and RANTES, in acute lung inflammatory injury induced by intrapulmonary deposition of IgG immune complexes injury in rats was determined. Rat MIP-1 beta, MCP-1, and RANTES...... were cloned, the proteins were expressed, and neutralizing Abs were developed. mRNA and protein expression for MIP-1 beta and MCP-1 were up-regulated during the inflammatory response, while mRNA and protein expression for RANTES were constitutive and unchanged during the inflammatory response....... Treatment of rats with anti-MIP-1 beta Ab significantly decreased vascular permeability by 37% (p = 0.012), reduced neutrophil recruitment into lung by 65% (p = 0.047), and suppressed levels of TNF-alpha in bronchoalveolar lavage fluids by 61% (p = 0.008). Treatment of rats with anti-rat MCP-1 or anti...
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EST Table: AB046365 [KAIKOcDNA[Archive
Lifescience Database Archive (English)
Full Text Available 1073 aa FBpp0259641|DyakGE14631-PA 10/08/27 47 %/329 aa W03F8.5#CE34386#WBGene00002247#locus:lam- 1#laminin#...AB046365 10/09/29 97 %/1069 aa dbj|BAB21565.1| laminin [Bombyx mori] 10/08/27 40 %/
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Directory of Open Access Journals (Sweden)
Tiantao Zhang
2014-09-01
Full Text Available Two colonies of Asian corn borer, Ostrinia furnacalis (Guenée, artificially selected from a Bt-susceptible colony (ACB-BtS for resistance to Cry1Ab (ACB-AbR and Cry1Ac (ACB-AcR toxins, were used to analyze inheritance patterns of resistance to Cry1 toxins. ACB-AbR and ACB-AcR evolved significant levels of resistance, with resistance ratios (RR of 39-fold and 78.8-fold to Cry1Ab and Cry1Ac, respectively. The susceptibility of ACB-AbR larvae to Cry1Ac and Cry1F toxins, which had not previously been exposed, were significantly reduced, being >113-fold and 48-fold, respectively. Similarly, susceptibility of ACB-AcR larvae to Cry1Ab and Cry1F were also significantly reduced (RR > nine-fold, RR > 18-fold, respectively, indicating cross-resistance among Cry1Ab, Cry1Ac, and Cry1F toxins. However, ACB-AbR and ACB-AcR larvae were equally susceptible to Cry1Ie as were ACB-BtS larvae, indicating no cross-resistance between Cry1Ie and Cry1Ab or Cry1Ac toxins; this may provide considerable benefits in preventing or delaying the evolution of resistance in ACB to Cry1Ab and Cry1Ac toxins. Backcrossing studies indicated that resistance to Cry1Ab toxin was polygenic in ACB-AbR, but monogenic in ACB-AcR, whilst resistance to Cry1Ac toxin was primarily monogenic in both ACB-AbR and ACB-AcR, but polygenic as resistance increased.
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AB/sub 5/-catalyzed hydrogen evolution cathodes
Energy Technology Data Exchange (ETDEWEB)
Hall, D E; Sawada, T; Shepard, V R; Tsujikawa, Y
1984-01-01
The AB/sub 5/ metal compounds are highly efficient hydrogen evolution electrocatalysts in alkaline electrolyte. Three types of AB/sub 5/-catalyzed cathode structures were made, using the hydride-forming AB/sub 5/ compounds in particulate form. Plastic-bonded cathodes containing >90 w/o AB/sub 5/ (finished-weight basis) were the most efficient, giving hydrogen evolution overpotentials (/eta/ /SUB H2/ ) of about 0.05 V at 200 mA cm/sup -2/. However, they tended to swell and shed material during electrolysis. Pressed, sintered cathodes containing 40-70 w/o catalyst in a nickel binder gave /eta/ /SUB H2/ about0.08 V; catalyst retention was excellent. Porous, sintered cathode coatings were made with 30-70 w/o AB/sub 5/ catalyst loadings. Their overpotentials were similar to those of the pressed, sintered cathodes. However, at catalyst loadings below about 40 w/o, high overpotentials characteristic of the nickel binder were observed. The structural and electrochemical properties of the three AB/sub 5/-catalyzed cathodes are discussed.
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International Nuclear Information System (INIS)
Bai, Zhiman; Wang, Xin; Tang, Gang; Song, Lei; Hu, Yuan; Yuen, Richard K.K.
2013-01-01
Highlights: • Oligomers with different chemical components in molecular chains were synthesized. • FP-3 containing three IFR components possessed high thermal stability. • FP-3 possessed lowest flammability. • FP-3 exhibited a synergistic interaction between gas and condensed phase. - Abstract: A series of flame retardant oligomers with different chemical components in molecular chains, designated as FP-1, FP-2 and FP-3, respectively, were successfully synthesized using solution polycondensation and well characterized. The thermal properties and flammability of these oligomers were investigated by thermogravimetric analysis (TGA) and microscale combustion calorimeter (MCC). The results demonstrated that FP-3 had the lowest flammability in terms of the lowest maximum mass loss rate, and FP-1 possessed the highest thermal stability and char yield, due to its higher stable hexatomic ring structure of piperazine compared with the linear alkane chain structure of neopentyl glycol. The gases evolved during decomposition were analyzed using Fourier transform infrared coupled with the thermogravimetric analyzer (TG–IR) technique. The char residues of the flame retardant oligomers were investigated by scanning electron microscopy (SEM) and Raman spectroscopy. The results demonstrated that FP-3 exhibited a synergistic interaction between the gas phase and condensation phase, increasing its flame retardancy
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Wang, Y-L; Li, G; Fu, Y-X; Wang, H; Shen, Z-Y
2013-01-01
The aim of this study was to investigate cytokine messenger RNA (mRNA) expression by peripheral blood mononuclear cells (PBMCs) from renal recipients experiencing acute rejection by blocking OX40-OX40L interactions with recombinant human OX40-Fc fusion protein (rhOX40Fc) in vitro. PBMCs were isolated from 20 recipients experiencing acute rejection episodes (rejection group) and 20 recipients with stable graft function (stable group). Levels of Th1 (interferon [IFN]-γ) and Th2 (interleukin [IL]-4) mRNA expressions by PBMCs were measured using real-time reverse transcriptase-polymerase chain reactions. IFN-γ mRNA expression levels were significantly higher in the rejection than the stable group (P rejection group, rhOX40Fc reduced significantly the expression of IFN-γ and IL-4 mRNA by anti-CD3-monoclonal antibody stimulated PBMCs (P type cytokines. Copyright © 2013 Elsevier Inc. All rights reserved.
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Iyoda, Masahiko; Hasegawa, Masashi
2015-01-01
The construction of redox-active supramolecular assemblies based on star-shaped and radially expanded tetrathiafulvalene (TTF) oligomers with divergent and extended conjugation is summarized. Star-shaped TTF oligomers easily self-aggregate with a nanophase separation to produce supramolecular structures, and their TTF units stack face-to-face to form columnar structures using the fastener effect. Based on redox-active self-organizing supramolecular structures, conducting nanoobjects are constructed by doping of TTF oligomers with oxidants after the formation of such nanostructures. Although radical cations derived from TTF oligomers strongly interact in solution to produce a mixed-valence dimer and π-dimer, it seems to be difficult to produce nanoobjects of radical cations different from those of neutral TTF oligomers. In some cases, however, radical cations form nanostructured fibers and rods by controlling the supramolecular assembly, oxidation states, and counter anions employed.
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Diffusivities and Viscosities of Poly(ethylene oxide) Oligomers †
Hong, Bingbing; Escobedo, Fernando; Panagiotopoulos, Athanassios Z.
2010-01-01
Diffusivities and viscosities of poly(ethylene oxide) (PEO) oligomer melts with 1 to 12 repeat units have been obtained from equilibrium molecular dynamics simulations using the TraPPE-UA force field. The simulations generated diffusion coefficients
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Oligomers and Polymers Based on Pentacene Building Blocks
Lehnherr, Dan; Tykwinski, Rik R.
2010-01-01
Functionalized pentacene derivatives continue to provide unique materials for organic semiconductor applications. Although oligomers and polymers based on pentacene building blocks remain quite rare, recent synthetic achievements have provided a number of examples with varied structural motifs. This review highlights recent work in this area and, when possible, contrasts the properties of defined-length pentacene oligomers to those of mono- and polymeric systems.
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International Nuclear Information System (INIS)
Huemmer, T.F.; Edison, B.A.
1977-01-01
A process is described for the high energy radiation curing of oligomers for use as coatings. The method is particularly applicable to the reaction products of certain low molecular weight epoxy compounds and certain low molecular weight mono-hydroxy vinyl compounds having at least one vinylic unsaturation. The curable mixture is applied as a thin film and cured very quickly
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Electrorheology of aniline oligomers
Czech Academy of Sciences Publication Activity Database
Mrlík, M.; Sedlačík, M.; Pavlínek, V.; Bober, Patrycja; Trchová, Miroslava; Stejskal, Jaroslav; Sáha, P.
2013-01-01
Roč. 291, č. 9 (2013), s. 2079-2086 ISSN 0303-402X R&D Projects: GA ČR GA202/09/1626 Institutional support: RVO:61389013 Keywords : anilin e oligomers * polyaniline * electrorheology Subject RIV: JI - Composite Materials Impact factor: 2.410, year: 2013
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Zhu, Linling; Zhang, Junying; Wang, Fengyang; Wang, Ya; Lu, Linlin; Feng, Chongchong; Xu, Zhiai; Zhang, Wen
2016-04-15
Amyloid-beta (Aβ) oligomers are highly toxic species in the process of Aβ aggregation and are regarded as potent therapeutic targets and diagnostic markers for Alzheimer's disease (AD). Herein, a label-free molecular beacon (MB) system integrated with enzyme-free amplification strategy was developed for simple and highly selective assay of Aβ oligomers. The MB system was constructed with abasic site (AP site)-containing stem-loop DNA and a fluorescent ligand 2-amino-5,6,7-trimethyl-1,8-naphyridine (ATMND), of which the fluorescence was quenched upon binding to the AP site in DNA stem. Enzyme-free amplification was realized by target-triggered continuous opening of two delicately designed MBs (MB1 and MB2). Target DNA hybridization with MB1 and then MB2 resulted in the release of two ATMND molecules in one binding event. Subsequent target recycling could greatly amplify the detection sensitivity due to the greatly enhanced turn-on emission of ATMND fluorescence. Combining with Aβ oligomers aptamers, the strategy was applied to analyze Aβ oligomers and the results showed that it could quantify Aβ oligomers with high selectivity and monitor the Aβ aggregation process. This novel method may be conducive to improve the diagnosis and pathogenic study of Alzheimer's disease. Copyright © 2015 Elsevier B.V. All rights reserved.
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Ultrafast Photoinduced Electron Transfer in a π-Conjugated Oligomer/Porphyrin Complex
Aly, Shawkat Mohammede
2014-10-02
Controlling charge transfer (CT), charge separation (CS), and charge recombination (CR) at the donor-acceptor interface is extremely important to optimize the conversion efficiency in solar cell devices. In general, ultrafast CT and slow CR are desirable for optimal device performance. In this Letter, the ultrafast excited-state CT between platinum oligomer (DPP-Pt(acac)) as a new electron donor and porphyrin as an electron acceptor is monitored for the first time using femtosecond (fs) transient absorption (TA) spectroscopy with broad-band capability and 120 fs temporal resolution. Turning the CT on/off has been shown to be possible either by switching from an organometallic oligomer to a metal-free oligomer or by controlling the charge density on the nitrogen atom of the porphyrin meso unit. Our time-resolved data show that the CT and CS between DPP-Pt(acac) and cationic porphyrin are ultrafast (approximately 1.5 ps), and the CR is slow (ns time scale), as inferred from the formation and the decay of the cationic and anionic species. We also found that the metallic center in the DPP-Pt(acac) oligomer and the positive charge on the porphyrin are the keys to switching on/off the ultrafast CT process.
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Oligomers and Polymers Based on Pentacene Building Blocks
Directory of Open Access Journals (Sweden)
Dan Lehnherr
2010-04-01
Full Text Available Functionalized pentacene derivatives continue to provide unique materials for organic semiconductor applications. Although oligomers and polymers based on pentacene building blocks remain quite rare, recent synthetic achievements have provided a number of examples with varied structural motifs. This review highlights recent work in this area and, when possible, contrasts the properties of defined-length pentacene oligomers to those of mono- and polymeric systems.
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Wu, Kuo-Chen; Liou, Horng-Huei; Kao, Yu-Han; Lee, Chih-Yu; Lin, Chun-Jung
2017-08-01
Oligomeric α-synuclein is a key mediator in the pathogenesis of Parkinson's disease (PD) and is mainly cleared by autophagy-lysosomal pathway, whose dysfunction results in the accumulation and cell-to-cell transmission of α-synuclein. In this study, concomitant with the accumulation of iron and oligomeric α-synuclein, higher expression of a lysosomal iron transporter, natural resistance-associated macrophage protein-1 (Nramp1), was observed in microglia in post-mortem striatum of sporadic PD patients. Using Nramp1-deficient macrophage (RAW264.7) and microglial (BV-2) cells as in-vitro models, iron exposure significantly reduced the degradation rate of the administered human α-synuclein oligomers, which can be restored by the expression of the wild-type, but not mutant (D543N), Nramp1. Likewise, under iron overload condition, mice with functional Nramp1 (DBA/2 and C57BL/6 congenic mice carrying functional Nramp1) had a better ability to degrade infused human α-synuclein oligomers than mice with nonfunctional Nramp1 (C57BL/6) in the brain and microglia. The interplay between iron and Nramp1 exhibited parallel effects on the clearance of α-synuclein and the activity of lysosomal cathepsin D in vitro and in vivo. Collectively, these findings suggest that the function of Nramp1 contributes to microglial degradation of oligomeric α-synuclein under iron overload condition and may be implicated in the pathogenesis of PD. Copyright © 2017 Elsevier Inc. All rights reserved.
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Amyloid oligomers and protofibrils, but not filaments, self-replicate from native lysozyme.
Mulaj, Mentor; Foley, Joseph; Muschol, Martin
2014-06-25
Self-assembly of amyloid fibrils is the molecular mechanism best known for its connection with debilitating human disorders such as Alzheimer's disease but is also associated with various functional cellular responses. There is increasing evidence that amyloid formation proceeds along two distinct assembly pathways involving either globular oligomers and protofibrils or rigid monomeric filaments. Oligomers, in particular, have been implicated as the dominant molecular species responsible for pathogenesis. Yet the molecular mechanisms regulating their self-assembly have remained elusive. Here we show that oligomers/protofibrils and monomeric filaments, formed along distinct assembly pathways, display critical differences in their ability to template amyloid growth at physiological vs denaturing temperatures. At physiological temperatures, amyloid filaments remained stable but could not seed growth of native monomers. In contrast, oligomers and protofibrils not only remained intact but were capable of self-replication using native monomers as the substrate. Kinetic data further suggested that this prion-like growth mode of oligomers/protofibrils involved two distinct activities operating orthogonal from each other: autocatalytic self-replication of oligomers from native monomers and nucleated polymerization of oligomers into protofibrils. The environmental changes to stability and templating competence of these different amyloid species in different environments are likely to be important for understanding the molecular mechanisms underlying both pathogenic and functional amyloid self-assembly.
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Iadevaia, Giulia; Núñez-Villanueva, Diego; Stross, Alexander E; Hunter, Christopher A
2018-06-06
Synthetic oligomers equipped with complementary H-bond donor and acceptor side chains form multiply H-bonded duplexes in organic solvents. Comparison of the duplex forming properties of four families of oligomers with different backbones shows that formation of an extended duplex with three or four inter-strand H-bonds is more challenging than formation of complexes that make only two H-bonds. The stabilities of 1 : 1 complexes formed between length complementary homo-oligomers equipped with either phosphine oxide or phenol recognition modules were measured in toluene. When the backbone is very flexible (pentane-1,5-diyl thioether), the stability increases uniformly by an order of magnitude for each additional base-pair added to the duplex: the effective molarities for formation of the first intramolecular H-bond (duplex initiation) and subsequent intramolecular H-bonds (duplex propagation) are similar. This flexible system is compared with three more rigid backbones that are isomeric combinations of an aromatic ring and methylene groups. One of the rigid systems behaves in exactly the same way as the flexible backbone, but the other two do not. For these systems, the effective molarity for formation of the first intramolecular H-bond is the same as that found for the other two backbones, but additional H-bonds are not formed between the longer oligomers. The effective molarities are too low for duplex propagation in these systems, because the oligomer backbones cannot adopt conformations compatible with formation of an extended duplex.
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Energy Technology Data Exchange (ETDEWEB)
Ohkawa, Mayumi [Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Ohno, Yoshiya [Laboratory of Immunobiology, Department of Pharmacy, School of Pharmacy, Hyogo University of Health Sciences, Kobe-shi, Hyogo 650-8530 (Japan); Masuko, Kazue; Takeuchi, Akiko; Suda, Kentaro; Kubo, Akihiro; Kawahara, Rieko; Okazaki, Shogo [Cell Biology Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, Kinki University, 4-1 Kowakae 3-chome, Higashiosaka-shi, Osaka 577-8502 (Japan); Tanaka, Toshiyuki [Laboratory of Immunobiology, Department of Pharmacy, School of Pharmacy, Hyogo University of Health Sciences, Kobe-shi, Hyogo 650-8530 (Japan); Saya, Hideyuki [Division of Gene Regulation, Institute for Advanced Medical Research, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8502 (Japan); Seki, Masayuki; Enomoto, Takemi [Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Yagi, Hideki [Cell Biology Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, Kinki University, 4-1 Kowakae 3-chome, Higashiosaka-shi, Osaka 577-8502 (Japan); Hashimoto, Yoshiyuki [Tohoku University, Sendai (Japan); Masuko, Takashi, E-mail: masuko@phar.kindai.ac.jp [Cell Biology Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, Kinki University, 4-1 Kowakae 3-chome, Higashiosaka-shi, Osaka 577-8502 (Japan)
2011-03-25
Highlights: {yields} We established LAT1 amino-acid transporter-disrupted DT40 cells. {yields} LAT1-disrupted cells showed slow growth and lost the oncogenicity. {yields} siRNA and mAb inhibited human tumor growth in vitro and in vivo. {yields} LAT1 is a promising target molecule for cancer therapy. -- Abstract: L-type amino-acid transporter 1 (LAT1) is the first identified light chain of CD98 molecule, disulfide-linked to a heavy chain of CD98. Following cDNA cloning of chicken full-length LAT1, we have constructed targeting vectors for the disruption of chicken LAT1 gene from genomic DNA of chicken LAT1 consisting of 5.4 kb. We established five homozygous LAT1-disrupted (LAT1{sup -/-}) cell clones, derived from a heterozygous LAT1{sup +/-} clone of DT40 chicken B cell line. Reactivity of anti-chicken CD98hc monoclonal antibody (mAb) with LAT1{sup -/-} DT40 cells was markedly decreased compared with that of wild-type DT40 cells. All LAT1{sup -/-} cells were deficient in L-type amino-acid transporting activity, although alternative-splice variant but not full-length mRNA of LAT1 was detected in these cells. LAT1{sup -/-} DT40 clones showed outstandingly slow growth in liquid culture and decreased colony-formation capacity in soft agar compared with wild-type DT40 cells. Cell-cycle analyses indicated that LAT1{sup -/-} DT40 clones have prolonged cell-cycle phases compared with wild-type or LAT1{sup +/-} DT40 cells. Knockdown of human LAT1 by small interfering RNAs resulted in marked in vitro cell-growth inhibition of human cancer cells, and in vivo tumor growth of HeLa cells in athymic mice was significantly inhibited by anti-human LAT1 mAb. All these results indicate essential roles of LAT1 in the cell proliferation and occurrence of malignant phenotypes and that LAT1 is a promising candidate as a molecular target of human cancer therapy.
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International Nuclear Information System (INIS)
Ohkawa, Mayumi; Ohno, Yoshiya; Masuko, Kazue; Takeuchi, Akiko; Suda, Kentaro; Kubo, Akihiro; Kawahara, Rieko; Okazaki, Shogo; Tanaka, Toshiyuki; Saya, Hideyuki; Seki, Masayuki; Enomoto, Takemi; Yagi, Hideki; Hashimoto, Yoshiyuki; Masuko, Takashi
2011-01-01
Highlights: → We established LAT1 amino-acid transporter-disrupted DT40 cells. → LAT1-disrupted cells showed slow growth and lost the oncogenicity. → siRNA and mAb inhibited human tumor growth in vitro and in vivo. → LAT1 is a promising target molecule for cancer therapy. -- Abstract: L-type amino-acid transporter 1 (LAT1) is the first identified light chain of CD98 molecule, disulfide-linked to a heavy chain of CD98. Following cDNA cloning of chicken full-length LAT1, we have constructed targeting vectors for the disruption of chicken LAT1 gene from genomic DNA of chicken LAT1 consisting of 5.4 kb. We established five homozygous LAT1-disrupted (LAT1 -/- ) cell clones, derived from a heterozygous LAT1 +/- clone of DT40 chicken B cell line. Reactivity of anti-chicken CD98hc monoclonal antibody (mAb) with LAT1 -/- DT40 cells was markedly decreased compared with that of wild-type DT40 cells. All LAT1 -/- cells were deficient in L-type amino-acid transporting activity, although alternative-splice variant but not full-length mRNA of LAT1 was detected in these cells. LAT1 -/- DT40 clones showed outstandingly slow growth in liquid culture and decreased colony-formation capacity in soft agar compared with wild-type DT40 cells. Cell-cycle analyses indicated that LAT1 -/- DT40 clones have prolonged cell-cycle phases compared with wild-type or LAT1 +/- DT40 cells. Knockdown of human LAT1 by small interfering RNAs resulted in marked in vitro cell-growth inhibition of human cancer cells, and in vivo tumor growth of HeLa cells in athymic mice was significantly inhibited by anti-human LAT1 mAb. All these results indicate essential roles of LAT1 in the cell proliferation and occurrence of malignant phenotypes and that LAT1 is a promising candidate as a molecular target of human cancer therapy.
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International Nuclear Information System (INIS)
Kordatos, Apostolis; Kelaidis, Nikolaos; Giamini, Sigiava Aminalragia; Marquez-Velasco, Jose; Xenogiannopoulou, Evangelia; Tsipas, Polychronis; Kordas, George; Dimoulas, Athanasios
2016-01-01
Highlights: • Growth of non-defective few layer graphene on Rh(1 1 1) substrates using an ambient- pressure CVD method. • Control of graphene stacking order via the cool-down rate. • Graphene is grown with a mainly AB-stacking geometry on single-crystalline Rhodium for a slow cool-down rate and non-AB for a very fast cool-down. • Good epitaxial orientation of the surface is presented through the RHEED data and confirmed with ARPES characterization for the lower cool-down rate, where graphene's ΓK direction a perfectly aligned with the ΓK direction of the Rh(1 1 1) single crystal. - Abstract: Graphene synthesis on single crystal Rh(1 1 1) catalytic substrates is performed by Chemical Vapor Deposition (CVD) at 1000 °C and atmospheric pressure. Raman analysis shows full substrate coverage with few layer graphene. It is found that the cool-down rate strongly affects the graphene stacking order. When lowered, the percentage of AB (Bernal) -stacked regions increases, leading to an almost full AB stacking order. When increased, the percentage of AB-stacked graphene regions decreases to a point where almost a full non AB-stacked graphene is grown. For a slow cool-down rate, graphene with AB stacking order and good epitaxial orientation with the substrate is achieved. This is indicated mainly by Raman characterization and confirmed by Reflection high-energy electron diffraction (RHEED) imaging. Additional Scanning Tunneling Microscopy (STM) topography data confirm that the grown graphene is mainly an AB-stacked structure. The electronic structure of the graphene/Rh(1 1 1) system is examined by Angle resolved Photo-Emission Spectroscopy (ARPES), where σ and π bands of graphene, are observed. Graphene's ΓK direction is aligned with the ΓK direction of the substrate, indicating no significant contribution from rotated domains.
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Energy Technology Data Exchange (ETDEWEB)
Kordatos, Apostolis [National Center for Scientific Research “Demokritos”, Athens, 15310 (Greece); Kelaidis, Nikolaos, E-mail: n.kelaidis@inn.demokritos.gr [National Center for Scientific Research “Demokritos”, Athens, 15310 (Greece); Giamini, Sigiava Aminalragia [National Center for Scientific Research “Demokritos”, Athens, 15310 (Greece); University of Athens, Department of Physics, Section of Solid State Physics, Athens, 15684 Greece (Greece); Marquez-Velasco, Jose [National Center for Scientific Research “Demokritos”, Athens, 15310 (Greece); National Technical University of Athens, Department of Physics, Athens, 15784 Greece (Greece); Xenogiannopoulou, Evangelia; Tsipas, Polychronis; Kordas, George; Dimoulas, Athanasios [National Center for Scientific Research “Demokritos”, Athens, 15310 (Greece)
2016-04-30
Highlights: • Growth of non-defective few layer graphene on Rh(1 1 1) substrates using an ambient- pressure CVD method. • Control of graphene stacking order via the cool-down rate. • Graphene is grown with a mainly AB-stacking geometry on single-crystalline Rhodium for a slow cool-down rate and non-AB for a very fast cool-down. • Good epitaxial orientation of the surface is presented through the RHEED data and confirmed with ARPES characterization for the lower cool-down rate, where graphene's ΓK direction a perfectly aligned with the ΓK direction of the Rh(1 1 1) single crystal. - Abstract: Graphene synthesis on single crystal Rh(1 1 1) catalytic substrates is performed by Chemical Vapor Deposition (CVD) at 1000 °C and atmospheric pressure. Raman analysis shows full substrate coverage with few layer graphene. It is found that the cool-down rate strongly affects the graphene stacking order. When lowered, the percentage of AB (Bernal) -stacked regions increases, leading to an almost full AB stacking order. When increased, the percentage of AB-stacked graphene regions decreases to a point where almost a full non AB-stacked graphene is grown. For a slow cool-down rate, graphene with AB stacking order and good epitaxial orientation with the substrate is achieved. This is indicated mainly by Raman characterization and confirmed by Reflection high-energy electron diffraction (RHEED) imaging. Additional Scanning Tunneling Microscopy (STM) topography data confirm that the grown graphene is mainly an AB-stacked structure. The electronic structure of the graphene/Rh(1 1 1) system is examined by Angle resolved Photo-Emission Spectroscopy (ARPES), where σ and π bands of graphene, are observed. Graphene's ΓK direction is aligned with the ΓK direction of the substrate, indicating no significant contribution from rotated domains.
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Antioxidant Activity of Hispidin Oligomers from Medicinal Fungi: A DFT Study
Directory of Open Access Journals (Sweden)
El Hassane Anouar
2014-03-01
Full Text Available Hispidin oligomers are styrylpyrone pigments isolated from the medicinal fungi Inonotus xeranticus and Phellinus linteus. They exhibit diverse biological activities and strong free radical scavenging activity. To rationalize the antioxidant activity of a series of four hispidin oligomers and determine the favored mechanism involved in free radical scavenging, DFT calculations were carried out at the B3P86/6-31+G (d, p level of theory in gas and solvent. The results showed that bond dissociation enthalpies of OH groups of hispidin oligomers (ArOH and spin density delocalization of related radicals (ArO• are the appropriate parameters to clarify the differences between the observed antioxidant activities for the four oligomers. The effect of the number of hydroxyl groups and presence of a catechol moiety conjugated to a double bond on the antioxidant activity were determined. Thermodynamic and kinetic studies showed that the PC-ET mechanism is the main mechanism involved in free radical scavenging. The spin density distribution over phenoxyl radicals allows a better understanding of the hispidin oligomers formation.
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Aggregation process of Aβ1-40 with non-Aβ amyloid component of α-synuclein
International Nuclear Information System (INIS)
Eugene, Cindie; Mousseau, Normand
2015-01-01
Many neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases, are characterized by the presence of amyloid fibers. Recently, attention has turned from the fibers to the early stages of oligomerization where toxicity could be highest. Here, we focus on the interactions between non-Aβ amyloid component of a-synuclein (NAC) and Aβ 1-40 , two proteins found in amyloid fibrils associated with Alzheimer's disease. We combine the coarse-grained OPEP potential with a Hamiltonian and temperature replica exchange molecular dynamics simulation (HT-REMD) to identify mechanisms leading to the formation of secondary structures promoting fibrillation. We observe that the propensity to form beta-sheet remains the same for Aβ 1-40 whereas is decreases significantly for NAC. In particular, the 25-35 region of Aβ 1-40 is a significant area of secondary structure stabilization with NAC. The ionic interactions between salt-bridge D23 and K28 in Aβ 1-40 and K20 and E23 in NAC of the heterogeneous dimer are consistent with the salt-bridges found in NAC and Aβ 1-40 homogenous dimers and allow us to see that these interactions don't necessarily dominate the interchain stabilizations. Our numerical simulation also show the formation of interaction between the early oligomer of NAC and Aβ 1-40 . (paper)
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Directory of Open Access Journals (Sweden)
Sara Sanz-Blasco
Full Text Available Dysregulation of intracellular Ca(2+ homeostasis may underlie amyloid beta peptide (Abeta toxicity in Alzheimer's Disease (AD but the mechanism is unknown. In search for this mechanism we found that Abeta(1-42 oligomers, the assembly state correlating best with cognitive decline in AD, but not Abeta fibrils, induce a massive entry of Ca(2+ in neurons and promote mitochondrial Ca(2+ overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Abeta oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca(2+ overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca(2+ overload, cytochrome c release and cell death induced by Abeta oligomers. Our results indicate that i mitochondrial Ca(2+ overload underlies the neurotoxicity induced by Abeta oligomers and ii inhibition of mitochondrial Ca(2+ overload provides a novel mechanism of neuroprotection by NSAIDs against Abeta oligomers and AD.
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Sanz-Blasco, Sara; Valero, Ruth A; Rodríguez-Crespo, Ignacio; Villalobos, Carlos; Núñez, Lucía
2008-07-23
Dysregulation of intracellular Ca(2+) homeostasis may underlie amyloid beta peptide (Abeta) toxicity in Alzheimer's Disease (AD) but the mechanism is unknown. In search for this mechanism we found that Abeta(1-42) oligomers, the assembly state correlating best with cognitive decline in AD, but not Abeta fibrils, induce a massive entry of Ca(2+) in neurons and promote mitochondrial Ca(2+) overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Abeta oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca(2+) overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs) including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca(2+) overload, cytochrome c release and cell death induced by Abeta oligomers. Our results indicate that i) mitochondrial Ca(2+) overload underlies the neurotoxicity induced by Abeta oligomers and ii) inhibition of mitochondrial Ca(2+) overload provides a novel mechanism of neuroprotection by NSAIDs against Abeta oligomers and AD.
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Liang, Yan; Zhang, Junxian; Yang, Yourong; Bai, Xuejuan; Yu, Qi; Li, Ning; Hou, Ying; Shi, Yingchang; Wang, Lan; Wu, Xueqiong
2017-07-13
The immune function of tuberculosis (TB) patients is disordered. By using immune regulators to assist chemotherapy for TB the curative effect might be improved. In this study, a vaccine containing Mycobacterium tuberculosis (M. tuberculosis) recombinant Ag85AB fusion protein (rAg85AB) was constructed and evaluated. The mice were immunized intramuscularly three times at two-week intervals with Ag85AB fusion protein combined with Corynebacterium parvum adjuvant (rAg85AB+CP). In comparison to control mice that received either CP alone or saline, the mice that received rAg85AB+CP had significantly higher number of T cells secreting IFN-γ and higher levels of specific antibodies of IgG, IgG1 and IgG2a isotypes in sera. The specific antibodies also had higher ratios of IgG2a to IgG1, indicating a predominant Th1 immune response. To test for immunotherapy of TB, M. tuberculosis infected mice were given three intramuscular doses of 20μg, 40μg or 60μg of rAg85AB in rAg85AB+CP, or phosphate-buffered saline (PBS), or CP or Mycobacterium phlei (M. Phlei) F.U.36. Compared with the PBS group, 20µg, 40µg and 60µg rAg85AB+CP and M. phlei F.U.36 groups reduced the pulmonary bacterial loads by 0.13, 0.15, 0.42 and 0.40 log 10 , and the liver bacterial loads by 0.64, 0.64, 0.53 and 0.61 log 10 , respectively. Pathological changes of lungs were less, and the lesions were limited to a certain extent in 40µg and 60µg rAg85AB+CP and M. phlei F.U.36 groups. These results showed that rAg85AB+CP had immunotherapeutic effect on TB, significantly increasing the cellular immune response, and inhibiting the growth of M. tuberculosis. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Labelling of MoAb with 153SmH1ETA: Preliminary results
International Nuclear Information System (INIS)
Ferro-Flores, G.; De, F.; Ramirez, M.; Pedraza-Lopez, M.; Tendilla, J.I.; Melendez-Alafort, L.; Murphy, C.A.
2001-01-01
A method to label MoAb with Sm-153 using 1,5,9,13-tetraazacyclohexadecane N,N',N'',N''' tetraacetic acid (H 4 ETA) as a bifunctional chelator was developed. H 4 ETA and SmH 1 ETA were synthesized in our laboratory and characterized by IR spectroscopy, TGA (thermogravimetric analysis), SEM (Scattering Electronic Microscopy), EDAX (Elemental Dispersion Analysis by X-rays) and EPR (Electron Paramagnetic Resonance) at 6 K. The 153 SmH 1 ETAMoAb was prepared by a simple incubation of the MoAb ior cea1, and the 153 SmH 1 ETA complex at neutral pH and at room temperature for 24 h. The specific activity of the labelled antibody was 111 MBq/mg (3 mCi/mg). Sm-153(III) is commercially available with specific activities up to 318.2 GBq/mg. Therefore, under the conditions described above 153 SmH 1 ETA labelled MoAb could be obtained with specific activity up to 1.14 GBq/mg (30.7 mCi/mg). (author)
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Podocyte changes after induction of acute albuminuria in mice by anti-aminopeptidase A mAb.
Dijkman, Henry B P M; Gerlofs-Nijland, Miriam E; van der Laak, Jeroen A W M; Wetzels, Jack F M; Groenen, Patricia J T A; Assmann, Karel J M
2003-01-01
Administration of a specific combination of anti-aminopeptidase A (APA) mAb (ASD-37/41) in mice induces an acute albuminuria which is independent of angiotensin II, a well-known substrate of APA. In the present experiments, we examined whether binding of the mAb initiated changes in the podocytic expression of cytoskeleton (-associated), adhesion and slit-diaphragm proteins in relation to the time course of albuminuria. In addition, we measured ultrastructurally the extent of foot process retraction (the number of foot processes per microm GBM) and the width of the slit pore between the podocytes by morphometric methods. An injection of the mAb combination ASD-37/41 induced a massive but transient albuminuria that started at 6 h, and peaked at 8 h, after which it declined. However, even at day 7 after injection of the mAbs some albuminuria was present. Injection of the combination ASD-3/41 or saline did not induce an albuminuria. Notably, we observed changes in the staining of CD2AP and podocin, two slit-pore-associated proteins that coincided with the start of the albuminuria. Nephrin staining was reduced and podocytic actin staining became more granular only at a time albuminuria was declining (24 h). The number of foot processes per microm GBM was already decreased at 4 h with a further reduction thereafter. The width of the slit pore was unchanged at the time of peak albuminuria and gradually decreased thereafter. At day 7, podocytic foot process effacement was even more prominent although albuminuria was only slightly abnormal. Expression of CD2AP was still granular. We observed however a change toward normal in the expression of podocin. Injection of saline or ASD-3/41 had no effect on the expression of podocytic proteins, the number of foot processes or width of the slit pore. Our data show that the onset of albuminuria in the anti-APA model is related to alterations in CD2AP and podocin, proteins that are important for maintaining slit-diaphragm structure
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Photo-electron spectroscopy study of energy levels in conjugated oligomers
Veenstra, SC; Heeres, A; Stalmach, U; Wildeman, J; Hadziioannou, G; Sawatzky, GA; Jonkman, HT; Moss, SC
2002-01-01
We report on the valence orbital structure of poly(para-phenylenevinylene) (PPV)-like oligomers. We studied these molecules as isolated oligomers in the gas phase, as well as in thin films deposited on metal substrates. We use a simple model based on a previously reported Hamiltonian that accurately
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Boncina, M; Rescic, J; Kalyuzhnyi, Yu V; Vlachy, V
2007-07-21
The depletion interaction between proteins caused by addition of either uncharged or partially charged oligomers was studied using the canonical Monte Carlo simulation technique and the integral equation theory. A protein molecule was modeled in two different ways: either as (i) a hard sphere of diameter 30.0 A with net charge 0, or +5, or (ii) as a hard sphere with discrete charges (depending on the pH of solution) of diameter 45.4 A. The oligomers were pictured as tangentially jointed, uncharged, or partially charged, hard spheres. The ions of a simple electrolyte present in solution were represented by charged hard spheres distributed in the dielectric continuum. In this study we were particularly interested in changes of the protein-protein pair-distribution function, caused by addition of the oligomer component. In agreement with previous studies we found that addition of a nonadsorbing oligomer reduces the phase stability of solution, which is reflected in the shape of the protein-protein pair-distribution function. The value of this function in protein-protein contact increases with increasing oligomer concentration, and is larger for charged oligomers. The range of the depletion interaction and its strength also depend on the length (number of monomer units) of the oligomer chain. The integral equation theory, based on the Wertheim Ornstein-Zernike approach applied in this study, was found to be in fair agreement with Monte Carlo results only for very short oligomers. The computer simulations for a model mimicking the lysozyme molecule (ii) are in qualitative agreement with small-angle neutron experiments for lysozyme-dextran mixtures.
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Directory of Open Access Journals (Sweden)
Amit Kumar
Full Text Available The aggregation of amyloid-β (Aβ peptide and its deposition in parts of the brain form the central processes in the etiology of Alzheimer disease (AD. The low-molecular weight oligomers of Aβ aggregates (2 to 30 mers are known to be the primary neurotoxic agents whose mechanisms of cellular toxicity and synaptic dysfunction have received substantial attention in the recent years. However, how these toxic agents proliferate and induce widespread amyloid deposition throughout the brain, and what mechanism is involved in the amplification and propagation of toxic oligomer species, are far from clear. Emerging evidence based on transgenic mice models indicates a transmissible nature of Aβ aggregates and implicates a prion-like mechanism of oligomer propagation, which manifests as the dissemination and proliferation of Aβ toxicity. Despite accumulating evidence in support of a transmissible nature of Aβ aggregates, a clear, molecular-level understanding of this intriguing mechanism is lacking. Recently, we reported the characterization of unique replicating oligomers of Aβ42 (12-24 mers in vitro called Large Fatty Acid-derived Oligomers (LFAOs (Kumar et al., 2012, J. Biol. Chem. In the current report, we establish that LFAOs possess physiological activity by activating NF-κB in human neuroblastoma cells, and determine the experimental parameters that control the efficiency of LFAO replication by self-propagation. These findings constitute the first detailed report on monomer - oligomer lateral propagation reactions that may constitute potential mechanism governing transmissibility among Aβ oligomers. These data support the previous reports on transmissible mechanisms observed in transgenic animal models.
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Dicty_cDB: Contig-U05695-1 [Dicty_cDB
Lifescience Database Archive (English)
Full Text Available -709P8, WORKING... 44 1.2 3 ( EU926921 ) Bactrocera cucurbitae voucher YSUW95011901 16S ri... 40 1.2 2 ( CP0...01056 ) Clostridium botulinum B str. Eklund 17B, complete... 34 1.6 16 ( AB048754 ) Bactrocera cucurbitae mi...tochondrial genes for 16S... 40 1.6 2 ( AB048748 ) Bactrocera cucurbitae mitochon...drial genes for 16S... 40 1.6 2 ( AB035113 ) Bactrocera cucurbitae mitochondrial genes for 16S... 40 1.6 2 (... AB035112 ) Bactrocera cucurbitae mitochondrial genes for 16S... 40 1.6 2 ( AB048746 ) Bactrocera tau mitoch
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Applications of oligomers for nanostructured conducting polymers.
Wang, Yue; Tran, Henry D; Kaner, Richard B
2011-01-03
This Feature Article provides an overview of the distinctive nanostructures that aniline oligomers form and the applications of these oligomers for shaping the nanoscale morphologies and chirality of conducting polymers. We focus on the synthetic methods for achieving such goals and highlight the underlying mechanisms. The clear advantages of each method and their possible drawbacks are discussed. Assembly and applications of these novel organic (semi)conducting nanomaterials are also outlined. We conclude this article with our perspective on the main challenges, new opportunities, and future directions for this nascent yet vibrant field of research. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Energy Technology Data Exchange (ETDEWEB)
Iarmoliuk, V.M.; Garun, Ia.E.; Ostroverkhov, V.G.; Pustovit, V.E.; Tikhonov, V.P.
1980-01-01
By the method of proton magnetic resonance, investigation was made of the structure of hydrocarbon framework of isobutylene oligomers of the Salavatsk petrochemical plant, produced by the cation polymerization of the isobutane isobutylene fraction at a temperature from -10 to +20/sup 0/ with A1C1/sub 3/ and used in the production of succinide additives. Determination was made of the qualitative and quantitative compositions of the various structures in the oligomers. It is shown, that as a rule, oligobutenes are not pure oligomers of isobutylene, but represent, at least, fragments of four structures, which can be formed on the basis of isobutylene. The content of the given structures does not affect the reaction capacity of the oligomers in respect to the maleic anhydride. It was established, that the low molecular fraction, contained in oligomers up to 5%, are not isobutylene oligomers, but represent a low molecular polymer of butene-2 and its copolymer with isobutylene.
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Patel, Yogesh S.
2014-01-01
Novel oligomer metal complexes (2a–f) of the ligand 2,5-bis((4-bromophenyl)carbamoyl) terephthalic acid (1) were prepared using transition metal salts and characterized by various spectroscopic techniques. The geometry of oligomer metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. Polymeric properties have also been carried out. Ligand was synthesized using pyromellitic dianhydride and 4-bromoaniline. It was duly characterized. All novel synthesi...
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Sequence-specific unusual (1-->2)-type helical turns in alpha/beta-hybrid peptides.
Prabhakaran, Panchami; Kale, Sangram S; Puranik, Vedavati G; Rajamohanan, P R; Chetina, Olga; Howard, Judith A K; Hofmann, Hans-Jörg; Sanjayan, Gangadhar J
2008-12-31
This article describes novel conformationally ordered alpha/beta-hybrid peptides consisting of repeating l-proline-anthranilic acid building blocks. These oligomers adopt a compact, right-handed helical architecture determined by the intrinsic conformational preferences of the individual amino acid residues. The striking feature of these oligomers is their ability to display an unusual periodic pseudo beta-turn network of nine-membered hydrogen-bonded rings formed in the forward direction of the sequence by 1-->2 amino acid interactions both in solid-state and in solution. Conformational investigations of several of these oligomers by single-crystal X-ray diffraction, solution-state NMR, and ab initio MO theory suggest that the characteristic steric and dihedral angle restraints exerted by proline are essential for stabilizing the unusual pseudo beta-turn network found in these oligomers. Replacing proline by the conformationally flexible analogue alanine (Ala) or by the conformationally more constrained alpha-amino isobutyric acid (Aib) had an adverse effect on the stabilization of this structural architecture. These findings increase the potential to design novel secondary structure elements profiting from the steric and dihedral angle constraints of the amino acid constituents and help to augment the conformational space available for synthetic oligomer design with diverse backbone structures.
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Laser-Induced Population Inversion in Rhodamine 6G for Lysozyme Oligomer Detection.
Hanczyc, Piotr; Sznitko, Lech
2017-06-06
Fluorescence spectroscopy is a common method for detecting amyloid fibrils in which organic fluorophores are used as markers that exhibit an increase in quantum yield upon binding. However, most of the dyes exhibit enhanced emission only when bound to mature fibrils, and significantly weaker signals are obtained in the presence of amyloid oligomers. In the concept of population inversion, a laser is used as an excitation source to keep the major fraction of molecules in the excited state to create the pathways for the occurrence of stimulated emission. In the case of the proteins, the conformational changes lead to the self-ordering and thus different light scattering conditions that can influence the optical signatures of the generated light. Using this methodology, we show it is possible to optically detect amyloid oligomers using commonly available staining dyes in which population inversion can be induced. The results indicate that rhodamine 6G molecules are complexed with oligomers, and using a laser-assisted methodology, weakly emissive states can be detected. Significant spectral red-shifting of rhodamine 6G dispersed with amyloid oligomers and a notable difference determined by comparison of spectra of the fibrils suggest the existence of specific dye aggregates around the oligomer binding sites. This approach can provide new insights into intermediate oligomer states that are believed to be responsible for toxic seeding in neurodegeneration diseases.
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Cry1Ab protein from Bt transgenic rice does not residue in rhizosphere soil
International Nuclear Information System (INIS)
Wang Haiyan; Ye Qingfu; Wang Wei; Wu Licheng; Wu Weixiang
2006-01-01
Expression of Cry1Ab protein in Bt transgenic rice (KMD) and its residue in the rhizosphere soil during the whole growth in field, as well as degradation of the protein from KMD straw in five soils under laboratory incubation were studied. The residue of Cry1Ab protein in KMD rhizosphere soil was undetectable (below the limit of 0.5 ng/g air-dried soil). The Cry1Ab protein contents in the shoot and root of KMD were 3.23-8.22 and 0.68-0.89 μg/g (fresh weight), respectively. The half-lives of the Cry1Ab protein in the soils amended with KMD straw (4%, w/w) ranged from 11.5 to 34.3 d. The residence time of the protein varied significantly in a Fluvio-marine yellow loamy soil amended with KMD straw at the rate of 3, 4 and 7%, with half-lives of 9.9, 13.8 and 18 d, respectively. In addition, an extraction method for Cry1Ab protein in soil was developed, with extraction efficiencies of 46.4-82.3%. - Cry1Ab protein was not detected in the rhizosphere soil of field-grown Bt transgenic rice
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Abe, Yutaka; Mutsuga, Motoh; Ohno, Hiroyuki; Kawamura, Yoko; Akiyama, Hiroshi
2016-01-01
Small amounts of cyclic monomers and oligomers are present in polyamide (PA)-based kitchen utensils. In this study, we isolated eight PA-based cyclic monomers and oligomers from kitchen utensils made from PA6 (a polymer of ε-caprolactam) and PA66 (a polymer of 1,6-diaminohexane and adipic acid). Their structures were identified using high-resolution mass spectrometry and 1H- and 13C-nuclear magnetic resonance spectroscopy, and their residual levels in PA-based kitchen utensils and degree of migration into food simulants were quantified by high-performance liquid chromatography/mass spectrometry using purchased PA6 monomer and isolated PA66 monomers, and isolated PA6 and PA66 oligomers as calibration standards. Their total residual levels among 23 PA-based kitchen utensils made from PA6, PA66, and copolymers of PA6 and PA66 (PA6/66) ranged from 7.8 to 20 mg/g. Using water, 20% ethanol, and olive oil as food simulants, the total migration levels of the PA monomers and oligomers ranged from 0.66 to 100 μg/cm2 under most examined conditions. However, the total migration levels of the PA66 monomer and oligomers from PA66 and PA6/66 kitchen utensils into 20% ethanol at 95°C were very high (1,700 and 2,200 μg/cm2, respectively) due to swelling by high-temperature ethanol.
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Directory of Open Access Journals (Sweden)
Yutaka Abe
Full Text Available Small amounts of cyclic monomers and oligomers are present in polyamide (PA-based kitchen utensils. In this study, we isolated eight PA-based cyclic monomers and oligomers from kitchen utensils made from PA6 (a polymer of ε-caprolactam and PA66 (a polymer of 1,6-diaminohexane and adipic acid. Their structures were identified using high-resolution mass spectrometry and 1H- and 13C-nuclear magnetic resonance spectroscopy, and their residual levels in PA-based kitchen utensils and degree of migration into food simulants were quantified by high-performance liquid chromatography/mass spectrometry using purchased PA6 monomer and isolated PA66 monomers, and isolated PA6 and PA66 oligomers as calibration standards. Their total residual levels among 23 PA-based kitchen utensils made from PA6, PA66, and copolymers of PA6 and PA66 (PA6/66 ranged from 7.8 to 20 mg/g. Using water, 20% ethanol, and olive oil as food simulants, the total migration levels of the PA monomers and oligomers ranged from 0.66 to 100 μg/cm2 under most examined conditions. However, the total migration levels of the PA66 monomer and oligomers from PA66 and PA6/66 kitchen utensils into 20% ethanol at 95°C were very high (1,700 and 2,200 μg/cm2, respectively due to swelling by high-temperature ethanol.
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International Nuclear Information System (INIS)
Zhu, Min; Li, Guanghui; Li, Min; Zhou, Zikai; Liu, Hong; Lei, Hongtao; Shen, Yanfei; Wan, Yakun
2015-01-01
We describe an electrochemical immunoassay for the Cry1Ab toxin that is produced by Bacillus thuringiensis. It is making use of a nanobody (a heavy-chain only antibody) that was selected from an immune phage displayed library. A biotinylated primary nanobody and a HRP-conjugated secondary nanobody were applied in a sandwich immunoassay where horseradish peroxidase (HRP) is used to produce polyaniline (PANI) from aniline. PANI can be easily detected by differential pulse voltammetry at a working voltage as low as 40 mV (vs. Ag/AgCl) which makes the assay fairly selective. This immunoassay for Cry1Ab has an analytical range from 0.1 to 1000 ng∙mL -1 and a 0.07 ng∙mL -1 lower limit of detection. The average recoveries of the toxin from spiked samples are in the range from 102 to 114 %, with a relative standard deviation of <7.5 %. The results demonstrated that the assay represented an attractive alternative to existing immunoassays in enabling affordable, sensitive, robust and specific determination of this toxin. (author)
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International Nuclear Information System (INIS)
Bhoir, S.A.; Chawla, S.P.
2016-01-01
Alginate oligomers formed by alginate lyase have been reported to possess antioxidant activity as well as prebiotic activity. Hence, utility of gamma radiation to depolymerise alginate in its aqueous solution was investigated and its antioxidant and prebiotic activities were screened. 1% aqueous solution of sodium alginate was subjected to gamma irradiation and it's reducing power and ability to scavenge DPPH". and O_2"."."-, chelate iron and prevent heat induced β-carotene bleaching was determined. Prebiotic activity was determined by using alginate oligomers to promote prebiotic activity of Lactobacillus plantarum against E coli. Gamma radiation induced depolymerisation of alginate resulted in formation of oligomers with antioxidant and prebiotic activity. These polymers are potential candidates for utilization as natural preservatives and functional foods
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Dicty_cDB: Contig-U04257-1 [Dicty_cDB
Lifescience Database Archive (English)
Full Text Available ne ... 48 0.40 1 ( EL483220 ) CHUM5135.b1_N11.ab1 CHU(LMS) puzzle sunflower Hel... 48 0.40 1 ( EL479670 ) CH...UM1646.b1_L03.ab1 CHU(LMS) puzzle sunflower Hel... 48 0.40 1 ( EL474614 ) CHUL2558.b1_K16.ab1 CHU(LMS) puz...zle sunflower Hel... 48 0.40 1 ( EL474613 ) CHUL2557.b1_I16.ab1 CHU(LMS) puzzle sun
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Aniline oligomers versus polyaniline
Czech Academy of Sciences Publication Activity Database
Stejskal, Jaroslav; Trchová, Miroslava
2012-01-01
Roč. 61, č. 2 (2012), s. 240-251 ISSN 0959-8103 R&D Projects: GA AV ČR IAA400500905; GA AV ČR IAA100500902; GA ČR GA203/08/0686; GA ČR GA202/09/1626 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyaniline * anilin e oligomers * anilin e Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.125, year: 2012
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Some biological actions of PEG-conjugated RNase A oligomers
Czech Academy of Sciences Publication Activity Database
Poučková, P.; Škvor, J.; Gotte, G.; Vottariello, F.; Slavík, Tomáš; Matoušek, Josef; Laurents, D. V.; Libonati, M.; Souček, J.
2006-01-01
Roč. 53, č. 1 (2006), s. 79-85 ISSN 0028-2685 R&D Projects: GA ČR GA523/04/0755; GA MZd NR8233 Grant - others:Spanish Ministerio de Ciencia y Technologia BQU2003-05227 Institutional research plan: CEZ:AV0Z50450515 Keywords : RNase A oligomers * polyethylene glycol conjugates * anti-tumour activity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.247, year: 2006
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Charge Separation and Recombination in Small Band Gap Oligomer-Fullerene Triads
Karsten, Bram P.; Bouwer, Ricardo K. M.; Hummelen, Jan C.; Williams, Rene M.; Janssen, Rene A. J.
2010-01-01
Synthesis and photophysics of a series of thiophene-thienopyrazine small band gap oligomers end-capped at both ends with C(60) are presented In these triads a photoinduced electron transfer reaction occurs between the oligomer as a donor and the fullerene as an acceptor Femtosecond photoinduced
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Zhu, Hao-Jun; Chen, Yi; Li, Yun-He; Wang, Jia-Mei; Ding, Jia-Tong; Chen, Xiu-Ping; Peng, Yu-Fa
2015-04-15
In fields of transgenic Bt rice, frogs are exposed to Bt proteins through consumption of both target and nontarget insects. In the present study, we assessed the risk posed by transgenic rice expressing a Cry1Ab/1Ac fusion protein (Huahui 1, HH1) on the development of Xenopus laevis. For 90 days, froglets were fed a diet with 30% HH1 rice, 30% parental rice (Minghui 63, MH63), or no rice as a control. Body weight and length were measured every 15 days. After sacrificing the froglets, we performed a range of biological, clinical, and pathological assessments. No significant differences were found in body weight (on day 90: 27.7 ± 2.17, 27.4 ± 2.40, and 27.9 ± 1.67 g for HH1, MH63, and control, respectively), body length (on day 90: 60.2 ± 1.55, 59.3 ± 2.33, and 59.7 ± 1.64 mm for HH1, MH63, and control, respectively), animal behavior, organ weight, liver and kidney function, or the microstructure of some tissues between the froglets fed on the HH1-containing diet and those fed on the MH63-containing or control diets. This indicates that frog development was not adversely affected by dietary intake of Cry1Ab/1Ac protein.
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Derosa, Pedro A
2009-06-01
A computationally cheap approach combining time-independent density functional theory (TIDFT) and semiempirical methods with an appropriate extrapolation procedure is proposed to accurately estimate geometrical and electronic properties of conjugated polymers using just a small set of oligomers. The highest occupied molecular orbital-lowest unoccupied molecular orbital gap (HLG) obtained at a TIDFT level (B3PW91) for two polymers, trans-polyacetylene--the simplest conjugated polymer, and a much larger poly(2-methoxy-5-(2,9-ethyl-hexyloxy)-1,4-phenylenevinylene (MEH-PPV) polymer converge to virtually the same asymptotic value than the excitation energy obtained with time-dependent DFT (TDDFT) calculations using the same functional. For TIDFT geometries, the HLG is found to converge to a value within the experimentally accepted range for the band gap of these polymers, when an exponential extrapolation is used; however if semiempirical geometries are used, a linear fit of the HLG versus 1/n is found to produce the best results. Geometrical parameters are observed to reach a saturation value in good agreement with experimental information, within the length of oligomers calculated here and no extrapolation was considered necessary. Finally, the performance of three different semiempirical methods (AM1, PM3, and MNDO) and for the TIDFT calculations, the performance of 7 different full electron basis sets (6-311+G**, 6-31+ +G**, 6-311+ +G**, 6-31+G**, 6-31G**, 6-31+G*, and 6-31G) is compared and it is determined that the choice of semiempirical method or the basis set does not significantly affect the results. 2008 Wiley Periodicals, Inc.
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De Haan, David O; Hawkins, Lelia N; Kononenko, Julia A; Turley, Jacob J; Corrigan, Ashley L; Tolbert, Margaret A; Jimenez, Jose L
2011-02-01
Reactions of methylglyoxal with amino acids, methylamine, and ammonium sulfate can take place in aqueous aerosol and evaporating cloud droplets. These processes are simulated by drying droplets and bulk solutions of these compounds (at low millimolar and 1 M concentrations, respectively) and analyzing the residuals by scanning mobility particle sizing, nuclear magnetic resonance, aerosol mass spectrometry (AMS), and electrospray ionization MS. The results are consistent with imine (but not diimine) formation on a time scale of seconds, followed by the formation of nitrogen-containing oligomers, methylimidazole, and dimethylimidazole products on a time scale of minutes to hours. Measured elemental ratios are consistent with imidazoles and oligomers being major reaction products, while effective aerosol densities suggest extensive reactions take place within minutes. These reactions may be a source of the light-absorbing, nitrogen-containing oligomers observed in urban and biomass-burning aerosol particles.
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Structural Investigations of on-pathway Oligomers of α-Synuclein
DEFF Research Database (Denmark)
Pedersen, Martin Nors; Horvath, Istvan; Weise, Christoph F.
Academy of Sciences of the United States of America 108(8): 3246-3251. Horvath, I., et al. (2012). "Mechanisms of protein oligomerization: In-hibitor of functional amyloids templates a-synuclein fibrilla-tion." Journal of the American Chemical Society. Spillantini, M. G., et al. (1997). "[alpha...... by decomposition of SAXS data from the evolving fibrillating solution (Giehm et al. 2011). NMR data have furthermore suggested that the C-terminal is exposed on oligomers obtained by incubation with the ligand FN075 (Horvath et al. 2012). In this study we aim at obtaining SAXS data from isolated stabilized...... oligomer (MAX-lab, May 2012); data analysis is in progress. ITC experiments are furthermore planned to more accurately determine the stoichiometry between α-synuclein and FN075. Horvath and co-workers have already shown that the FN075 stabilized oligomer is on pathway. We have shown that the in...
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International Nuclear Information System (INIS)
Miller, H.C.
1999-01-01
Typically those not skilled in the art relate Glass Transition Temperature to Pressure Sensitive Adhesives. You need a low Tg material to prepare good pressure sensitive adhesives. This report deals with a wide range acrylate terminated oligomers in a standard formulation. Molecular weight, chemical structure variations are examined versus the Glass Transition of the oligomers and final peel strength. Each formulated adhesive will require unique oligomer properties to reach one hundred newtons per 100 millimeters (5.71 pounds per square inch) peel strength. Excellent peel strengths may be obtained with oligomer molecular weight ranging from six thousand to one thousand molecular weight and glass transition temperatures ranging from minus seventy four degrees centigrade up to thirteen degrees centigrade
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Trikha, Saurabh; Jeremic, Aleksandar M.
2013-01-01
Toxic human amylin oligomers and aggregates are implicated in the pathogenesis of type 2 diabetes mellitus (TTDM). Although recent studies have shown that pancreatic cells can recycle amylin monomers and toxic oligomers, the exact uptake mechanism and trafficking routes of these molecular forms and their significance for amylin toxicity are yet to be determined. Using pancreatic rat insulinoma (RIN-m5F) beta (β)-cells and human islets as model systems we show that monomers and oligomers cross the plasma membrane (PM) through both endocytotic and non-endocytotic (translocation) mechanisms, the predominance of which is dependent on amylin concentrations and incubation times. At low (≤100 nM) concentrations, internalization of amylin monomers in pancreatic cells is completely blocked by the selective amylin-receptor (AM-R) antagonist, AC-187, indicating an AM-R dependent mechanism. In contrast at cytotoxic (µM) concentrations monomers initially (1 hour) enter pancreatic cells by two distinct mechanisms: translocation and macropinocytosis. However, during the late stage (24 hours) monomers internalize by a clathrin-dependent but AM-R and macropinocytotic independent pathway. Like monomers a small fraction of the oligomers initially enter cells by a non-endocytotic mechanism. In contrast a majority of the oligomers at both early (1 hour) and late times (24 hours) traffic with a fluid-phase marker, dextran, to the same endocytotic compartments, the uptake of which is blocked by potent macropinocytotic inhibitors. This led to a significant increase in extra-cellular PM accumulation, in turn potentiating amylin toxicity in pancreatic cells. Our studies suggest that macropinocytosis is a major but not the only clearance mechanism for both amylin’s molecular forms, thereby serving a cyto-protective role in these cells. PMID:24019897
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Synthesis of soybean oil-based thiol oligomers.
Wu, Jennifer F; Fernando, Shashi; Weerasinghe, Dimuthu; Chen, Zhigang; Webster, Dean C
2011-08-22
Industrial grade soybean oil (SBO) and thiols were reacted to generate thiol-functionalized oligomers via a thermal, free radical initiated thiol-ene reaction between the SBO double bond moieties and the thiol functional groups. The effect of the reaction conditions, including thiol concentration, catalyst loading level, reaction time, and atmosphere, on the molecular weight and the conversion to the resultant soy-thiols were examined in a combinatorial high-throughput fashion using parallel synthesis, combinatorial FTIR, and rapid gel permeation chromatography (GPC). High thiol functionality and concentration, high thermal free radical catalyst concentration, long reaction time, and the use of a nitrogen reaction atmosphere were found to favor fast consumption of the SBO, and produced high molecular weight products. The thiol conversion during the reaction was inversely affected by a high thiol concentration, but was favored by a long reaction time and an air reaction atmosphere. These experimental observations were explained by the initial low affinity of the SBO and thiol, and the improved affinity between the generated soy-thiol oligomers and unreacted SBO during the reaction. The synthesized soy-thiol oligomers can be used for renewable thiol-ene UV curable materials and high molecular solids and thiourethane thermal cure materials. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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International Nuclear Information System (INIS)
Masuhara, Kenichi; Mori, Koji; Koshiishi, Kenji; Sasaki, Takashi.
1995-01-01
Adhesion of poly (ethylene terephthalate) film by Electron Beam Curing (EBC) method which can be thought as an energy-saving process was studied for the purpose of bestowing economically design and distinctness of image on thermosetting high molecular weight polyester precoated steel sheets. Adhesion of EB curable resins onto metal is generally poor. In this report, addition of EB curable phenolic resole oligomer with bifunctional acrylates to the top coat used for precoated steel was studied in order to increase the adhesion of an EB curable adhesive, and it was found that the phenolic oligomer is tremendously effective for the improvement of adhesion. The reasons why the phenolic oligomer provides excellent adhesion were 1) elongation at break of the top coat to which the phenolic oligomer is added is little decreased by EB irradiation, and the formability does not reduce. 2) As the phenolic oligomer is unevenly distributed to the surface layer of the top coat, it is suggested that the contact frequency of the phenolic oligomer to the EB curable adhesive is so high that graft polymerization between them is liable to occur. (author)
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Field-evolved resistance to Cry1Ab maize by Spodoptera frugiperda in Brazil.
Omoto, Celso; Bernardi, Oderlei; Salmeron, Eloisa; Sorgatto, Rodrigo J; Dourado, Patrick M; Crivellari, Augusto; Carvalho, Renato A; Willse, Alan; Martinelli, Samuel; Head, Graham P
2016-09-01
The first Bt maize in Brazil was launched in 2008 and contained the MON 810 event, which expresses Cry1Ab protein. Although the Cry1Ab dose in MON 810 is not high against fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), MON 810 provided commercial levels of control. To support insect resistance management in Brazil, the baseline and ongoing susceptibility of FAW was examined using protein bioassays, and the level of control and life history parameters of FAW were evaluated on MON 810 maize. Baseline diet overlay assays with Cry1Ab (16 µg cm(-2) ) caused 76.3% mortality to field FAW populations sampled in 2009. Moderate mortality (48.8%) and significant growth inhibition (88.4%) were verified in leaf-disc bioassays. In greenhouse trials, MON 810 had significantly less damage than non-Bt maize. The surviving FAW larvae on MON 810 (22.4%) had a 5.5 day increase in life cycle time and a 24% reduction in population growth rate. Resistance monitoring (2010-2015) showed a significant reduction in Cry1Ab susceptibility of FAW over time. Additionally, a significant reduction in the field efficacy of MON 810 maize against FAW was observed in different regions from crop season 2009 to 2013. The decrease in susceptibility to Cry1Ab was expected, but the specific contributions to this resistance by MON 810 maize cannot be distinguished from cross-resistance to Cry1Ab caused by exposure to Cry1F maize. Technologies combining multiple novel insecticidal traits with no cross-resistance to the current Cry1 proteins and high activity against the same target pests should be pursued in Brazil and similar environments. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.
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Detection of the electronic structure of iron-(iii)-oxo oligomers forming in aqueous solutions.
Seidel, Robert; Kraffert, Katrin; Kabelitz, Anke; Pohl, Marvin N; Kraehnert, Ralph; Emmerling, Franziska; Winter, Bernd
2017-12-13
The nature of the small iron-oxo oligomers in iron-(iii) aqueous solutions has a determining effect on the chemical processes that govern the formation of nanoparticles in aqueous phase. Here we report on a liquid-jet photoelectron-spectroscopy experiment for the investigation of the electronic structure of the occurring iron-oxo oligomers in FeCl 3 aqueous solutions. The only iron species in the as-prepared 0.75 M solution are Fe 3+ monomers. Addition of NaOH initiates Fe 3+ hydrolysis which is followed by the formation of iron-oxo oligomers. At small enough NaOH concentrations, corresponding to approximately [OH]/[Fe] = 0.2-0.25 ratio, the iron oligomers can be stabilized for several hours without engaging in further aggregation. Here, we apply a combination of non-resonant as well as iron 2p and oxygen 1s resonant photoelectron spectroscopy from a liquid microjet to detect the electronic structure of the occurring species. Specifically, the oxygen 1s partial electron yield X-ray absorption (PEY-XA) spectra are found to exhibit a peak well below the onset of liquid water and OH - (aq) absorption. The iron 2p absorption gives rise to signal centered between the main absorption bands typical for aqueous Fe 3+ . Absorption bands in both PEY-XA spectra are found to correlate with an enhanced photoelectron peak near 20 eV binding energy, which demonstrates the sensitivity of resonant photoelectron (RPE) spectroscopy to mixing between iron and ligand orbitals. These various signals from the iron-oxo oligomers exhibit maximum intensity at [OH]/[Fe] = 0.25 ratio. For the same ratio, we observe changes in the pH as well as in complementary Raman spectra, which can be assigned to the transition from monomeric to oligomeric species. At approximately [OH]/[Fe] = 0.3 we begin to observe particles larger than 1 nm in radius, detected by small-angle X-ray scattering.
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NMR studies of DNA oligomers and their interactions with minor groove binding ligands
Energy Technology Data Exchange (ETDEWEB)
Fagan, Patricia A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry
1996-05-01
The cationic peptide ligands distamycin and netropsin bind noncovalently to the minor groove of DNA. The binding site, orientation, stoichiometry, and qualitative affinity of distamycin binding to several short DNA oligomers were investigated by NMR spectroscopy. The oligomers studied contain A,T-rich or I,C-rich binding sites, where I = 2-desaminodeoxyguanosine. I•C base pairs are functional analogs of A•T base pairs in the minor groove. The different behaviors exhibited by distamycin and netropsin binding to various DNA sequences suggested that these ligands are sensitive probes of DNA structure. For sites of five or more base pairs, distamycin can form 1:1 or 2:1 ligand:DNA complexes. Cooperativity in distamycin binding is low in sites such as AAAAA which has narrow minor grooves, and is higher in sites with wider minor grooves such as ATATAT. The distamycin binding and base pair opening lifetimes of I,C-containing DNA oligomers suggest that the I,C minor groove is structurally different from the A,T minor groove. Molecules which direct chemistry to a specific DNA sequence could be used as antiviral compounds, diagnostic probes, or molecular biology tools. The author studied two ligands in which reactive groups were tethered to a distamycin to increase the sequence specificity of the reactive agent.
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Kwak, Dong Hoon; Moussavou, Ghislain; Lee, Ju Hyoung; Heo, Sung Youn; Ko, Kisung; Hwang, Kyung-A; Jekal, Seung-Joo; Choo, Young-Kug
2014-11-14
We have generated the transgenic Tabaco plants expressing multiple monoclonal antibody (mAb) CO7-1A × BR55 by cross-pollinating with mAb CO17-1A and mAb BR55. We have demonstrated the anti-cancer effect of plant-derived multiple mAb CO17-1A × BR55. We find that co-treatment of colorectal mAbs (anti-epithelial cellular adhesion molecule (EpCAM), plant-derived monoclonal antibody (mAb(P)) CO17-1A and mAb(P) CO17-1A × BR55) with RAW264.7 cells significantly inhibited the cell growth in SW620 cancer cells. In particular, multi mAb(P) CO17-1A × BR55 significantly and efficiently suppressed the growth of SW620 cancer cells compared to another mAbs. Apoptotic death-positive cells were significantly increased in the mAb(P) CO17-1A × BR55-treated. The mAb(P) CO17-1A × BR55 treatment significantly decreased the expression of B-Cell lymphoma-2 (BCl-2), but the expression of Bcl-2-associated X protein (Bax), and cleaved caspase-3 were markedly increased. In vivo, the mAb(P) CO17-1A × BR55 significantly and efficiently inhibited the growth of colon tumors compared to another mAbs. The apoptotic cell death and inhibition of pro-apoptotic proteins expression were highest by treatment with mAb(P) CO17-1A × BR55. In addition, the mAb(P) CO17-1A × BR55 significantly inhibited the extracellular signal-regulated kinase 1 and 2 (ERK1/2) phosphorylation in cancer cells and tumors. Therefore, this study results suggest that multiple mAb(P) CO17-1A × BR55 has a significant effect on apoptosis-mediated anticancer by suppression of ERK1/2 phosphorylation in colon cancer compared to another mAbs. In light of these results, further clinical investigation should be conducted on mAb(P) CO17-1A × BR55 to determine its possible chemopreventive and/or therapeutic efficacy against human colon cancer.
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Preparation of Chito-Oligomers by Hydrolysis of Chitosan in the Presence of Zeolite as Adsorbent
Ibrahim, Khalid A.; El-Eswed, Bassam I.; Abu-Sbeih, Khaleel A.; Arafat, Tawfeeq A.; Al Omari, Mahmoud M. H.; Darras, Fouad H.; Badwan, Adnan A.
2016-01-01
An increasing interest has recently been shown to use chitin/chitosan oligomers (chito-oligomers) in medicine and food fields because they are not only water-soluble, nontoxic, and biocompatible materials, but they also exhibit numerous biological properties, including antibacterial, antifungal, and antitumor activities, as well as immuno-enhancing effects on animals. Conventional depolymerization methods of chitosan to chito-oligomers are either chemical by acid-hydrolysis under harsh conditions or by enzymatic degradation. In this work, hydrolysis of chitosan to chito-oligomers has been achieved by applying adsorption-separation technique using diluted HCl in the presence of different types of zeolite as adsorbents. The chito-oligomers were retrieved from adsorbents and characterized by differential scanning calorimetry (DSC), liquid chromatography/mass spectroscopy (LC/MS), and ninhydrin test. PMID:27455287
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Report on the Personnel Dosimetry at AB Atomenergi during 1962
Energy Technology Data Exchange (ETDEWEB)
Edvardsson, K A; Hagsgaard, S
1964-07-15
This report presents the results of the personnel dosimetry at AB Atomenergi during 1963. No doses exceeding the recommendations of ICRP have been reported. The sum of the reported external total body doses during the year is for AB Atomenergi 64.2 manrem which, distributed over the whole company personnel, corresponds to about 40 mrem per year and person or about 1 % of the maximum permissible dose. 37800 gamma films and 6700 neutron films have been evaluated. The total number of urine analyses is 3603 and of whole body measurements 211.
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International Nuclear Information System (INIS)
Pitt, Jason; Roth, William; Lacor, Pascale; Smith, Amos B.; Blankenship, Matthew; Velasco, Pauline; De Felice, Fernanda; Breslin, Paul; Klein, William L.
2009-01-01
It now appears likely that soluble oligomers of amyloid-β 1-42 peptide, rather than insoluble fibrils, act as the primary neurotoxin in Alzheimer's disease (AD). Consequently, compounds capable of altering the assembly state of these oligomers (referred to as ADDLs) may have potential for AD therapeutics. Phenolic compounds are of particular interest for their ability to disrupt Aβ oligomerization and reduce pathogenicity. This study has focused on oleocanthal (OC), a naturally-occurring phenolic compound found in extra-virgin olive oil. OC increased the immunoreactivity of soluble Aβ species, when assayed with both sequence- and conformation-specific Aβ antibodies, indicating changes in oligomer structure. Analysis of oligomers in the presence of OC showed an upward shift in MW and a ladder-like distribution of SDS-stable ADDL subspecies. In comparison with control ADDLs, oligomers formed in the presence of OC (Aβ-OC) showed equivalent colocalization at synapses but exhibited greater immunofluorescence as a result of increased antibody recognition. The enhanced signal at synapses was not due to increased synaptic binding, as direct detection of fluorescently-labeled ADDLs showed an overall reduction in ADDL signal in the presence of OC. Decreased binding to synapses was accompanied by significantly less synaptic deterioration assayed by drebrin loss. Additionally, treatment with OC improved antibody clearance of ADDLs. These results indicate oleocanthal is capable of altering the oligomerization state of ADDLs while protecting neurons from the synaptopathological effects of ADDLs and suggest OC as a lead compound for development in AD therapeutics.
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Direct Correlation Between Ligand-Induced α-Synuclein Oligomers and Amyloid-like Fibril Growth
DEFF Research Database (Denmark)
Pedersen, Martin Nors; Foderà, Vito; Horvath, Istvan
2015-01-01
link to disease related degenerative activity. Fibrils formed in the presence and absence of FN075 are indistinguishable on microscopic and macroscopic levels. Using small angle X-ray scattering, we reveal that FN075 induced oligomers are similar, but not identical, to oligomers previously observed......Aggregation of proteins into amyloid deposits is the hallmark of several neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The suggestion that intermediate oligomeric species may be cytotoxic has led to intensified investigations of pre-fibrillar oligomers, which...
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Mao, Jie; Sun, Xing; Cheng, Jian-Hua; Shi, Yong-Jie; Wang, Xin-Zheng; Qin, Jun-Jie; Sang, Zhi-Hong; He, Kun; Xia, Qing
2016-09-01
A 52-week feeding study in cynomolgus macaques was carried out to evaluate the safety of Bt rice Huahui 1 (HH1), a transgenic rice line expressing Cry1Ab/1Ac protein. Monkeys were fed a diet with 20% or 60% HH1 rice, 20% or 60% parental rice (Minghui 63, MH63), normal diet, normal diet spiked with purified recombinant Cry1Ab/1Ac fusion protein or bovine serum albumin (BSA) respectively. During the feeding trail, clinical observations were conducted daily, and multiple parameters, including body weight, body temperature, electrocardiogram, hematology, blood biochemistry, serum metabolome and gut microbiome were examined at regular intervals. Upon sacrifice, the organs were weighted, and the macroscopic, microscopic and electron microscopic examinations were performed. The results show no adverse or toxic effects of Bt rice HH1 or Cry1Ab/1Ac fusion protein on monkeys. Therefore, the present 52-week primate feeding study suggests that the transgenic rice containing Cry 1Ab/1Ac is equivalent to its parental rice line MH63. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Macrocyclic 2,7-Anthrylene Oligomers.
Yamamoto, Yuta; Wakamatsu, Kan; Iwanaga, Tetsuo; Sato, Hiroyasu; Toyota, Shinji
2016-05-06
A macrocyclic compound consisting of six 2,7-anthrylene units was successfully synthesized by Ni-mediated coupling of the corresponding dibromo precursor as a novel π-conjugated compound. This compound was sufficiently stable and soluble in organic solvents due to the presence of mesityl groups. X-ray analysis showed that the molecule had a nonplanar and hexagonal wheel-shaped framework of approximately S6 symmetry. The dynamic process between two S6 structures was observed by using the dynamic NMR technique, the barrier being 58 kJ mol(-1) . The spectroscopic properties of the hexamer were compared with those of analogous linear oligomers. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Huang, Zhihao; Zhao, Junfei; Wang, Zimu; Meng, Fanying; Ding, Kunshan; Pan, Xiangqiang; Zhou, Nianchen; Li, Xiaopeng; Zhang, Zhengbiao; Zhu, Xiulin
2017-10-23
Orthogonal maleimide and thiol deprotections were combined with thiol-maleimide coupling to synthesize discrete oligomers/macromolecules on a gram scale with molecular weights up to 27.4 kDa (128mer, 7.9 g) using an iterative exponential growth strategy with a degree of polymerization (DP) of 2 n -1. Using the same chemistry, a "readable" sequence-defined oligomer and a discrete cyclic topology were also created. Furthermore, uniform dendrons were fabricated using sequential growth (DP=2 n -1) or double exponential dendrimer growth approaches (DP=22n -1) with significantly accelerated growth rates. A versatile, efficient, and metal-free method for construction of discrete oligomers with tailored structures and a high growth rate would greatly facilitate research into the structure-property relationships of sophisticated polymeric materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Preparation of Chito-Oligomers by Hydrolysis of Chitosan in the Presence of Zeolite as Adsorbent
Directory of Open Access Journals (Sweden)
Khalid A. Ibrahim
2016-07-01
Full Text Available An increasing interest has recently been shown to use chitin/chitosan oligomers (chito-oligomers in medicine and food fields because they are not only water-soluble, nontoxic, and biocompatible materials, but they also exhibit numerous biological properties, including antibacterial, antifungal, and antitumor activities, as well as immuno-enhancing effects on animals. Conventional depolymerization methods of chitosan to chito-oligomers are either chemical by acid-hydrolysis under harsh conditions or by enzymatic degradation. In this work, hydrolysis of chitosan to chito-oligomers has been achieved by applying adsorption-separation technique using diluted HCl in the presence of different types of zeolite as adsorbents. The chito-oligomers were retrieved from adsorbents and characterized by differential scanning calorimetry (DSC, liquid chromatography/mass spectroscopy (LC/MS, and ninhydrin test.
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International Nuclear Information System (INIS)
Haroun, A.A.; Masoud, R.A.; Bronco, S.; Ciardelli, F.
2005-01-01
The purpose of this study was to formulate the new combined system of acrylic and citric acids, which has been prepared by free radical polymerization and esterification reaction at the same time to form citric acrylate (CAC) oligomer through ester linkage and low molecular weight (Mw 2241), in compared with polyacrylic acid. The chemical structure and the reaction mechanism of this oligomer were confirmed by different spectroscopic tools (1 H , 13 C-NMR, ATR-IR), gel permeation chromatography and thermogravimetric analysis (TGA/DTA). The problem of the effect of the masking agents in the chrome tanning of the collagen and the pickling of the hide has been approached from the study of the hydrothermal and mechanical properties, using this new eco-friendly oligomer, which was carried out in-situ treated/grafted chrome tanned collagen (hide powder), and pickled hide. The microemulsion grafting copolymerization of (CAC) using 2.2-azo-bis isobutyronitrile (ABIN), via direct coupling reaction, onto the chrome tanned collagen showed that the free amino groups of the collagen were considered to be a potential site for the in-situ reaction with (CAC) oligomer. Also, using of citric-acrylate (CAC) oligomer, during chrome tanning of leather, instead of the traditional strong acids (sulfuric, hydrochloric and formic) resulted in significant improvement in chrome exhaustion and physical properties
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Ubeda, Sara; Aznar, Margarita; Nerín, Cristina
2018-03-01
An oligomer is a molecule that consists of a few monomer units. It can be formed during polymer manufacturing and also due to polymer degradation processes or even during use conditions. Since oligomers are not included in chemical databases, their identification is a complex process. In this work, the oligomers present in 20 different PET pellet samples have been determined. Two different sample treatment procedures, solvent extraction and total dissolution, were applied in order to select the most efficient one. The analyses were carried out by UPLC-MS-QTOF. The use of high resolution mass spectrometry allowed the structural elucidation of these compounds and their correct identification. The main oligomers identified were cyclic as well as lineal from the first, second, and third series. All of them were composed of terephthalic acid (TPA), diethylene glycol (DEG), and ethylene glycol (EG). Quantitative values were very different in both procedures. In total dissolution of PET samples, the concentration of oligomers was always, at least, 10 times higher than in solvent extraction; some of the compounds were only detected when total dissolution was used. Results showed that the oligomers with the highest concentration values were dimers and trimers, cyclic, as well as lineal, from the first and second series. The oligomer with the maximum concentration value was TPA 2 -EG-DEG that was found in all the samples in a concentration range from 2493 to 19,290 ng/g PET. No differences between virgin and recycled PET were found. Migration experiments were performed in two PET bottles, and results showed the transference of most of these oligomers to a fat food simulant (ethanol 95%). Graphical abstract Graphical abstract of the two procedures developd and optimized for identifying oligomers in PET pellets and in migration form PET bottles.
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Abe, Yutaka; Mutsuga, Motoh; Ohno, Hiroyuki; Kawamura, Yoko; Akiyama, Hiroshi
2016-01-01
Small amounts of cyclic monomers and oligomers are present in polyamide (PA)-based kitchen utensils. In this study, we isolated eight PA-based cyclic monomers and oligomers from kitchen utensils made from PA6 (a polymer of ε-caprolactam) and PA66 (a polymer of 1,6-diaminohexane and adipic acid). Their structures were identified using high-resolution mass spectrometry and 1H- and 13C-nuclear magnetic resonance spectroscopy, and their residual levels in PA-based kitchen utensils and degree of m...
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Bacchi, Ataís; Pfeifer, Carmem S
2016-08-01
Thio-urethane oligomers have been shown to reduce stress and increase toughness in highly filled composite materials. This study evaluated the influence of thio-urethane backbone structure on rheological and mechanical properties of resin cements modified with a fixed concentration of the oligomers. Thio-urethane oligomers (TU) were synthesized by combining thiols - pentaerythritol tetra-3-mercaptopropionate (PETMP) or trimethylol-tris-3-mercaptopropionate (TMP) - with isocyanates - 1,6-hexanediol-diissocyante (HDDI) (aliphatic) or 1,3-bis(1-isocyanato-1-methylethyl)benzene (BDI) (aromatic) or dicyclohexylmethane 4,4'-diisocyanate (HMDI) (cyclic), at 1:2 isocyanate:thiol, leaving pendant thiols. 20wt% TU were added to BisGMA-UDMA-TEGDMA (5:3:2). 60wt% silanated inorganic fillers were added. Near-IR was used to follow methacrylate conversion and rate of polymerization ( [Formula: see text] ). Mechanical properties were evaluated in three-point bending (ISO 4049) for flexural strength/modulus (FS/FM, and toughness), and notched specimens (ASTM Standard E399-90) for fracture toughness (KIC). PS was measured on the Bioman. Viscosity (V) and gel-points (defined as the crossover between storage and loss shear moduli (G'/G″)) were obtained with rheometry. Glass transition temperature (Tg), cross-link density and homogeneity of the network were obtained with dynamic mechanical analysis. Film-thickness was evaluated according to ISO 4049. DC and mechanical properties increased and [Formula: see text] and PS decreased with the addition of TUs. Gelation (G'/G″) was delayed and DC at G'/G″ increased in TU groups. Tg and cross-link density dropped in TU groups, while oligomers let to more homogenous networks. An increase in V was observed, with no effect on film-thickness. Significant reductions in PS were achieved at the same time conversion and mechanical properties increased. The addition of thio-urethane oligomers proved successful in improving several key properties
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Directory of Open Access Journals (Sweden)
Liping Chen
2017-11-01
Full Text Available Indirubins are natural occurring alkaloids extracted from indigo dye-containing plants. Indirubins could inhibit various kinases, and might be used to treat chronic myelocytic leukemia, cancer and neurodegenerative disorders. 7-bromoindirubin-3-oxime (7Bio, an indirubin derivative derived from indirubin-3-oxime, possesses inhibitory effects against cyclin-dependent kinase-5 (CDK5 and glycogen synthase kinase-3β (GSK3β, two pharmacological targets of Alzheimer's disease (AD. In this study, we have discovered that 2.3–23.3 μg/kg 7Bio effectively prevented β-amyloid (Aβ oligomer-induced impairments of spatial cognition and recognition without affecting bodyweight and motor functions in mice. Moreover, 7Bio potently inhibited Aβ oligomer-induced expression of interleukin-6 (IL-6 and tumor necrosis factor-α (TNF-α. Furthermore, 7Bio significantly prevented the decreased expression of synapsin-1 and PSD-95, biomarkers of pre-synaptic and post-synaptic proteins in Aβ oligomer-treated mice. The mean optical density (OD with hyper-phosphorylated tau (pTau, glial fibrillary acidic protein (GFAP and CD45 positive staining in the hippocampus of 7Bio-treated mice were significantly decreased compared to those of Aβ oligomer-treated mice. In addition, Western blotting analysis showed that 7Bio attenuated Aβ oligomer-decreased expression of pSer9-GSK3β. Those results suggested that 7Bio could potently inhibit Aβ oligomer-induced neuroinflammation, synaptic impairments, tau hyper-phosphorylation, and activation of astrocytes and microglia, which may contribute to the neuroprotective effects of 7Bio. Based on these findings, we expected that 7Bio might be developed as a novel anti-AD lead compound.
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Directory of Open Access Journals (Sweden)
Wen-bin Wan
Full Text Available Alzheimer's disease (AD is the most common form of senile dementia which is characterized by abnormal amyloid beta (Aβ accumulation and deposition in brain parenchyma and cerebral capillaries, and leads to blood-brain barrier (BBB disruption. Despite great progress in understanding the etiology of AD, the underlying pathogenic mechanism of BBB damage is still unclear, and no effective treatment has been devised. The standard Ginkgo biloba extract EGb761 has been widely used as a potential cognitive enhancer for the treatment of AD. However, the cellular mechanism underlying the effect remain to be clarified. In this study, we employed an immortalized endothelial cell line (bEnd.3 and incubation of Aβ(1-42 oligomer, to mimic a monolayer BBB model under conditions found in the AD brain. We investigated the effect of EGb761 on BBB and found that Aβ1-42 oligomer-induced cell injury, apoptosis, and generation of intracellular reactive oxygen species (ROS, were attenuated by treatment with EGb761. Moreover, treatment of the cells with EGb761 decreased BBB permeability and increased tight junction scaffold protein levels including ZO-1, Claudin-5 and Occludin. We also found that the Aβ(1-42 oligomer-induced upregulation of the receptor for advanced glycation end-products (RAGE, which mediates Aβ cytotoxicity and plays an essential role in AD progression, was significantly decreased by treatment with EGb761. To our knowledge, we provide the first direct in vitro evidence of an effect of EGb761 on the brain endothelium exposed to Aβ(1-42 oligomer, and on the expression of tight junction (TJ scaffold proteins and RAGE. Our results provide a new insight into a possible mechanism of action of EGb761. This study provides a rational basis for the therapeutic application of EGb761 in the treatment of AD.
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Influence of transgenic rice expressing a fused Cry1Ab/1Ac protein on frogs in paddy fields.
Wang, Jia-Mei; Chen, Xiu-Ping; Liang, Yu-Yong; Zhu, Hao-Jun; Ding, Jia-Tong; Peng, Yu-Fa
2014-11-01
As genetic engineering in plants is increasingly used to control agricultural pests, it is important to determine whether such transgenic plants adversely affect non-target organisms within and around cultivated fields. The cry1Ab/1Ac fusion gene from Bacillus thuringiensis (Bt) has insecticidal activity and has been introduced into rice line Minghui 63 (MH63). We evaluated the effect of transgenic cry1Ab/1Ac rice (Huahui 1, HH1) on paddy frogs by comparing HH1 and MH63 rice paddies with and without pesticide treatment. The density of tadpoles in rice fields was surveyed at regular intervals, and Cry1Ab/1Ac protein levels were determined in tissues of tadpoles and froglets collected from the paddy fields. In addition, Rana nigromaculata froglets were raised in purse nets placed within these experimental plots. The survival, body weight, feeding habits, and histological characteristics of the digestive tract of these froglets were analyzed. We found that the tadpole density was significantly decreased immediately after pesticide application, and the weight of R. nigromaculata froglets of pesticide groups was significantly reduced compared with no pesticide treatment, but we found no differences between Bt and non-Bt rice groups. Moreover, no Cry1Ab/1Ac protein was detected in tissue samples collected from 192 tadpoles and froglets representing all four experimental groups. In addition, R. nigromaculata froglets raised in purse seines fed primarily on stem borer and non-target insects, and showed no obvious abnormality in the microstructure of their digestive tracts. Based on these results, we conclude that cultivation of transgenic cry1Ab/1Ac rice does not adversely affect paddy frogs.
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DEFF Research Database (Denmark)
Paslawski, Wojciech; Mysling, Simon; Thomsen, Karen
2014-01-01
Neurodegenerative disorders are characterized by the formation of protein oligomers and amyloid fibrils, which in the case of Parkinson's disease involves the protein α-synuclein (αSN). Cytotoxicity is mainly associated with the oligomeric species, but we still know little about their assembly...... are protected from exchange with D2 O until they dissociate into monomeric αSN by EX1 exchange kinetics. Fewer residues are protected against exchange in oligomer type II, but this type does not revert to αSN monomers. Both oligomers are protected in the core sequence Y39-A89. Based on incubation studies...
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Directory of Open Access Journals (Sweden)
O.P. Shevchenko
2014-01-01
Full Text Available It is shown that liver transplantation (LT from donor with incompatible blood type (AB0i may be effective and safe, but the impact of such operation upon the various systems of the body has not been investigated yet. Insulinlike growth factor-1 (IGF-1 is synthesized in the liver and mediates the action of growth hormone. The level of IGF-1 is a marker of the processes of cell proliferation and tissue regeneration. Aim. To evaluate levels of IGF-1 in children-recipients with liver transplant from AB0i (incompatible and AB0c (compatible donors.Materials and methods. 140 children aged 3 to 36 (19,5 ± 16,5 months with congenital diseases of the hepatobiliar system, 58 of them boys, were surveyed. All patients underwent transplantation of left lateral liver sector from living related donors: 111 children were transplanted with fragment of the liver from AB0c donors, 29 – from AB0i donors; in 10 children with AB0i liver before and/or after LT operation anti-group antibodies (anti-A/B were revealed. The concentration of IGF-1 was determined by ELISA using specifi c kits (Immunodiagnostic System, USA in samples of blood plasma, which were received up to a month and a year after a liver transplant.Results. Average level of IGF-1 21,0 ± 29,5 μg/l in patients before LT was signifi cantly lower than in healthy children (52,2 ± 26,3 μg/l, p < 0,001 and did not vary in children, having received later a piece of liver from a compatible (AB0c donor and from donor AB0i (23,5 ± 30,9 and 21,2 ± 23,2 μg/l respectively, p = 0,70. In patients with anti-A/B prior to surgery average level of IGF-1 was not different from that of the patients without antibodies (32,6 ± 27,6 and 22,3 ± 29,6 μg/l respectively, p = 0,4. One month after LT level of IGF-1 has increased both in the general group, and in patients with AB0c and AV0i liver (92,1 ± 77,8 and 131,2 ± 106,7 μg/l respectively, p = 0,09. The level of IGF-1 was not varied in the group with antibodies
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Acute toxicity of emamectin benzoate and its desmethyl metabolite to Eohaustorius estuarius.
Kuo, Jen-Ni; Buday, Craig; van Aggelen, Graham; Ikonomou, Michael George; Pasternak, John
2010-08-01
Emamectin benzoate is one of the active ingredients of the anti-sealice drug SLICE. Ten-day acute sediment lethal tests (10-d LC50) of emamectin benzoate and its desmethyl metabolite (AB1) were conducted to determine LC50 values using a sensitive representative West Coast amphipod crustacean, Eohaustorius estuarius. The 10-d LC50s of emamectin benzoate and AB1 to E. estuarius were 0.185 and 0.019 mg/kg wet weight sediment (0.146 and 0.015 mg/kg dry wt), respectively. The degradation properties of emamectin benzoate and AB1 during the 10-d period were also measured and described. No obvious decay patterns were observed for either emamectin benzoate and AB1 over the 10-d period. Copyright 2010 SETAC
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Radiation-chemical hardening of phenol-formaldehyde oligomers
International Nuclear Information System (INIS)
Shlapatskaya, V.V.; Omel'chenko, S.I.
1978-01-01
Radiation-chemical hardening of phenol formaldehyde oligomers of the resol type has been studied in the presence of furfural and diallylphthalate diluents. The samples have been hardened on an electron accelerator at an electron energy of 1.0-1.1 MeV and a dose rate of 2-3 Mrad/s. The kinetics of hardening has been studied on the yield of gel fraction within the range of absorbed doses from 7 to 400 Mrad. Radiation-chemical hardening of the studied compositions is activated with sensitizers, namely, amines, metal chlorides, and heterocyclic derivatives of metals. Furfural and diallylphthalate compositions are suitable for forming glass-fibre plastic items by the wet method and coatings under the action of ionizing radiations
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Theoretical study of stability geometrical and electronic structure of (BeHsub(2))sub(n) oligomers
Energy Technology Data Exchange (ETDEWEB)
Sukhanov, L P; Boldyrev, A I; Charkin, O P [AN SSSR, Moscow. Inst. Novykh Khimicheskikh Problem
1983-01-01
The Hartree-Fock-Ruthane method with the Roos-Siegbahn two-exponent basis is used to calculate stability, geometrical and electronic structures of (BeHsub(2))sub(n) oligomers, where n=1, 2, 3, 4 and 6. It is shown that with the growth of oligomerization degree n stability of linear band structure is increased as compared with other configurations including high-coordination volumetric ones. Tendencies in formation with n growth of geometrical, energetic characteristics, electronic structure of (BeHsub(2))sub(n) oligomers of band type are analysed.
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2010-07-01
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry2Ab2 protein in corn and cotton; exemption from the requirement of a tolerance. 174.519 Section 174.519 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...
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Dicty_cDB: Contig-U01957-1 [Dicty_cDB
Lifescience Database Archive (English)
Full Text Available Synthetic construct DNA, clone: pF... 41 0.074 AB241241_1( AB241241 |pid:none) Symbiotic...me: Full=Rac-like GTP-binding protein 3; AltName: ... 38 0.82 AB241244_1( AB241244 |pid:none) Symbiotic prot... DQ667981 |pid:none) Gossypium hirsutum small GTPase (R... 40 0.13 AB241245_1( AB241245 |pid:none) Symbiot...ic protist of Reticuliterme... 40 0.17 BX538352_67( BX538352 |pid:none) Cryptospori
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Diniz, Luan Pereira; Tortelli, Vanessa; Matias, Isadora; Morgado, Juliana; Bérgamo Araujo, Ana Paula; Melo, Helen M; Seixas da Silva, Gisele S; Alves-Leon, Soniza V; de Souza, Jorge M; Ferreira, Sergio T; De Felice, Fernanda G; Gomes, Flávia Carvalho Alcantara
2017-07-12
Alzheimer's disease (AD) is characterized by progressive cognitive decline, increasingly attributed to neuronal dysfunction induced by amyloid-β oligomers (AβOs). Although the impact of AβOs on neurons has been extensively studied, only recently have the possible effects of AβOs on astrocytes begun to be investigated. Given the key roles of astrocytes in synapse formation, plasticity, and function, we sought to investigate the impact of AβOs on astrocytes, and to determine whether this impact is related to the deleterious actions of AβOs on synapses. We found that AβOs interact with astrocytes, cause astrocyte activation and trigger abnormal generation of reactive oxygen species, which is accompanied by impairment of astrocyte neuroprotective potential in vitro We further show that both murine and human astrocyte conditioned media (CM) increase synapse density, reduce AβOs binding, and prevent AβO-induced synapse loss in cultured hippocampal neurons. Both a neutralizing anti-transforming growth factor-β1 (TGF-β1) antibody and siRNA-mediated knockdown of TGF-β1, previously identified as an important synaptogenic factor secreted by astrocytes, abrogated the protective action of astrocyte CM against AβO-induced synapse loss. Notably, TGF-β1 prevented hippocampal dendritic spine loss and memory impairment in mice that received an intracerebroventricular infusion of AβOs. Results suggest that astrocyte-derived TGF-β1 is part of an endogenous mechanism that protects synapses against AβOs. By demonstrating that AβOs decrease astrocyte ability to protect synapses, our results unravel a new mechanism underlying the synaptotoxic action of AβOs in AD. SIGNIFICANCE STATEMENT Alzheimer's disease is characterized by progressive cognitive decline, mainly attributed to synaptotoxicity of the amyloid-β oligomers (AβOs). Here, we investigated the impact of AβOs in astrocytes, a less known subject. We show that astrocytes prevent synapse loss induced by A
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Jalali, Sushil K; Lalitha, Yadavalli; Kamath, Subray P; Mohan, Komarlingam S; Head, Graham P
2010-08-01
Genetically engineered corn (Bt corn) expressing Bacillus thuringiensis Berliner insecticidal protein Cry1Ab is a biotechnological option being considered for management of lepidopteran corn pests in India. As a resistance management practice it was essential to determine the sensitivity of multiple populations of the stalk borer Chilo partellus (Swinhoe), pink borer Sesamia inferens (Walker) and the cob borer Helicoverpa armigera (Hübner) to Cry1Ab protein through bioassays. The insect populations were collected during growing seasons of Rabi 2005 (October 2005 to February 2006) and Kharif 2006 (May to September 2006). Multiple populations of the three lepidopteran corn pests were found to be susceptible to Cry1Ab. Median lethal concentrations (LC(50)) ranged between 0.008 and 0.068 microg Cry1Ab mL(-1) diet for 18 populations of C. partellus (across two seasons), between 0.12 and 1.99 microg mL(-1) for seven populations of H. armigera and between 0.46 and 0.56 microg mL(-1) for two populations of S. inferens. Dose-response concentrations for lethality and growth inhibition have been determined to mark baseline sensitivity of multiple populations of key lepidopteran corn pests in India to Cry1Ab protein. These benchmark values will be referenced while monitoring resistance to Cry1Ab should Bt corn hybrids expressing Cry1Ab be approved for commercial cultivation in India. Copyright (c) 2010 Society of Chemical Industry.
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Energy Technology Data Exchange (ETDEWEB)
Kong, Qinggang, E-mail: gangq0172@163.com [Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, College of Environmental Science and Engineering, Nanjing University of Information Science and Technology, 219 Ningliu Road, Pukou District, Nanjing 210044 (China); Qian, Haiyan, E-mail: qianhaiy@163.com [College of Material Science and Technology, Nanjing University of Technology, 5 Xinmofan Road, Nanjing 210009 (China); Zhou, Yonghui; Li, Jun; Xiao, Huining [Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, College of Environmental Science and Engineering, Nanjing University of Information Science and Technology, 219 Ningliu Road, Pukou District, Nanjing 210044 (China)
2012-08-15
A monodispersed macrocyclic oligomer constructed by three triarylmine units ((TPAT){sub 3}) was designed and readily synthesized from the monomer of 3-(4 Prime -(phenyl(4 Double-Prime -methylphenyl)amino)-phenyl)pentan-3-ol (TPAT) by means of a simple Friedel-Crafts alkylation reaction. The structure of the resultant macrocycle was examined using FT-IR, NMR and MALDI-TOF mass spectroscopy. Compared with 1,10-bis(di-4-tolylaminophenyl) cyclohexane (TAPC) and tri-p-tolylamine (TTA), (TPAT){sub 3} possesses the three-dimensional chair conformation and the higher T{sub g}. In the photoluminescence (PL) spectrum of (TPAT){sub 3} film, there are no excimer emission peaks in the range of 400-550 nm region as those of TAPC and TTA. Besides an EL peak at 386 nm, the single-layer device occured only the 438 nm excimer emission peak, whose intensity increased with the excitation voltage increase. Using 1,3,5-Tris(N-phenylbenzimidazol-2-yl)-benzene (TPBI) as the electron-transporting layer, the resulting double-layer device ITO/(TPAT){sub 3} (40 nm)/TPBI (40 nm)/Mg:Ag (10:1; 50 nm)/Ag (100 nm) only exhibited a 438 nm maximum symmetrical emission peak under an excitation voltage of 14 V. However, as the applied voltage was increased from 14 V to 19 V, the intensity of the symmetrical curve with a 468 nm peak from exciplex emission gets stronger and stronger. In fact, the resultant emission curve was asymmetrical, due to the overlap of two symmetrical curves with 438 nm and 468 nm peaks, respectively. The maximum luminance and luminous efficiency are 2240 cd m{sup -2} at 18.8 V and 1.73 cd A{sup -1} at 1878 cd m{sup -2} (13.9 V). Highlights: Black-Right-Pointing-Pointer The monodispersed macrocyclic oligomer constructed by three triarylamine units was synthesized and characterized. Black-Right-Pointing-Pointer The PL of (TPAT){sub 3} film does not emerge TAPC and TTA's emission peaks of over 400 nm region. Black-Right-Pointing-Pointer The 438 nm emission peak was found from
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Scheijen, Blanca; Boer, Judith M; Marke, René; Tijchon, Esther; van Ingen Schenau, Dorette; Waanders, Esmé; van Emst, Liesbeth; van der Meer, Laurens T; Pieters, Rob; Escherich, Gabriele; Horstmann, Martin A; Sonneveld, Edwin; Venn, Nicola; Sutton, Rosemary; Dalla-Pozza, Luciano; Kuiper, Roland P; Hoogerbrugge, Peter M; den Boer, Monique L; van Leeuwen, Frank N
2017-03-01
Deletions and mutations affecting lymphoid transcription factor IKZF1 (IKAROS) are associated with an increased relapse risk and poor outcome in B-cell precursor acute lymphoblastic leukemia. However, additional genetic events may either enhance or negate the effects of IKZF1 deletions on prognosis. In a large discovery cohort of 533 childhood B-cell precursor acute lymphoblastic leukemia patients, we observed that single-copy losses of BTG1 were significantly enriched in IKZF1 -deleted B-cell precursor acute lymphoblastic leukemia ( P =0.007). While BTG1 deletions alone had no impact on prognosis, the combined presence of BTG1 and IKZF1 deletions was associated with a significantly lower 5-year event-free survival ( P =0.0003) and a higher 5-year cumulative incidence of relapse ( P =0.005), when compared with IKZF1 -deleted cases without BTG1 aberrations. In contrast, other copy number losses commonly observed in B-cell precursor acute lymphoblastic leukemia, such as CDKN2A/B, PAX5, EBF1 or RB1 , did not affect the outcome of IKZF1 -deleted acute lymphoblastic leukemia patients. To establish whether the combined loss of IKZF1 and BTG1 function cooperate in leukemogenesis, Btg1 -deficient mice were crossed onto an Ikzf1 heterozygous background. We observed that loss of Btg1 increased the tumor incidence of Ikzf1 +/- mice in a dose-dependent manner. Moreover, murine B cells deficient for Btg1 and Ikzf1 +/- displayed increased resistance to glucocorticoids, but not to other chemotherapeutic drugs. Together, our results identify BTG1 as a tumor suppressor in leukemia that, when deleted, strongly enhances the risk of relapse in IKZF1 -deleted B-cell precursor acute lymphoblastic leukemia, and augments the glucocorticoid resistance phenotype mediated by the loss of IKZF1 function. Copyright© Ferrata Storti Foundation.
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Directory of Open Access Journals (Sweden)
Takashi Yoshida
2018-03-01
Full Text Available In 1990, Okuda et al. reported the first isolation and characterization of oenothein B, a unique ellagitannin dimer with a macrocyclic structure, from the Oenothera erythrosepala leaves. Since then, a variety of macrocyclic analogs, including trimeric–heptameric oligomers have been isolated from various medicinal plants belonging to Onagraceae, Lythraceae, and Myrtaceae. Among notable in vitro and in vivo biological activities reported for oenothein B are antioxidant, anti-inflammatory, enzyme inhibitory, antitumor, antimicrobial, and immunomodulatory activities. Oenothein B and related oligomers, and/or plant extracts containing them have thus attracted increasing interest as promising targets for the development of chemopreventive agents of life-related diseases associated with oxygen stress in human health. In order to better understand the significance of this type of ellagitannin in medicinal plants, this review summarizes (1 the structural characteristics of oenothein B and related dimers; (2 the oxidative metabolites of oenothein B up to heptameric oligomers; (3 the distribution of oenotheins and other macrocyclic analogs in the plant kingdom; and (4 the pharmacological activities hitherto documented for oenothein B, including those recently found by our laboratory.
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Directory of Open Access Journals (Sweden)
Jenq-Renn Chen
2010-08-01
Full Text Available Oxidative degradation of commercial grade ABS (Acrylonitrile-butadiene-styrene resin powders was studied by thermal analysis. The instabilities of ABS containing different polybutadiene (PB contents with respect to temperature were studied by Differential Scanning Calorimeter (DSC. Thermograms of isothermal test and dynamic scanning were performed. Three exothermic peaks were observed and related to auto-oxidation, degradation and oxidative decomposition, respectively. Onset temperature of the auto-oxidation was determined to be around 193 °C. However, threshold temperature of oxidation was found to be as low as 140 °C by DSC isothermal testing. Another scan of the powder after degeneration in air showed an onset temperature of 127 °C. Reactive hazards of ABS powders were verified to be the exothermic oxidation of unsaturated PB domains, not the SAN (poly(styrene-acrylonitrile matrix. Heat of oxidation was first determined to be 2,800 ± 40 J per gram of ABS or 4,720 ± 20 J per gram of PB. Thermal hazards of processing ABS powder are assessed by adiabatic temperature rise at process conditions. IR spectroscopy associated with heat of oxidation verified the oxidative mechanism, and these evidences excluded the heat source from the degradation of SAN. A specially prepared powder of ABS without adding anti-oxidant was analyzed by DSC for comparing the exothermic behaviors. Exothermic onset temperatures were determined to be 120 °C and 80 °C by dynamic scanning and isothermal test, respectively. The assessment successfully explained fires and explosions in an ABS powder dryer and an ABS extruder.
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Physical and Mechanical Characteristics of Kevlar Fiber-Reinforced PC/ABS Composites
Directory of Open Access Journals (Sweden)
Kuljira Sujirote
2012-01-01
Full Text Available In this research, the composites between polycarbonate (PC and acrylonitrile-butadiene-styrene (ABS alloy and Kevlar fiber were prepared. The flexural and tensile properties of PC/ABS alloy and its composites were determined using a universal testing machine. The synergistic behavior of flexural modulus was observed for all regions of PC contents, while the synergism of flexural strength and tensile strength were found in some PC contents. It was found that the optimum weight ratio of PC:ABS was 60:40. In the Kevlar Fiber-reinforced PC/ABS composite system at PC:ABS of 60:40, both flexural modulus and strength were increased with matrix contents. Additionally, the flexural strength drastically increased with the matrix content and then reached the maximum value of 167 MPa at the matrix content of 33.4 wt%. The results from peel test, water contact measurement, and scanning electron microscopy (SEM reveal that the interfacial adhesion between the Kevlar fiber and the polymer matrix could be improved by increasing the PC content in the matrix.
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Qiu, Yulou; Li, Pan; Dong, Sa; Zhang, Xiaoshuai; Yang, Qianru; Wang, Yulong; Ge, Jing; Hammock, Bruce D; Zhang, Cunzheng; Liu, Xianjin
2018-01-31
Cry toxins have been widely used in genetically modified organisms for pest control, raising public concern regarding their effects on the natural environment and food safety. In this work, a phage-mediated competitive chemiluminescent immunoassay (c-CLIA) was developed for determination of Cry1Ab toxin using anti-idiotypic camel nanobodies. By extracting RNA from camels' peripheral blood lymphocytes, a naive phage-displayed nanobody library was established. Using anti-Cry1Ab toxin monoclonal antibodies (mAbs) against the library for anti-idiotypic antibody screening, four anti-idiotypic nanobodies were selected and confirmed to be specific for anti-Cry1Ab mAb binding. Thereafter, a c-CLIA was developed for detection of Cry1Ab toxin based on anti-idiotypic camel nanobodies and employed for sample testing. The results revealed a half-inhibition concentration of developed assay to be 42.68 ± 2.54 ng/mL, in the linear range of 10.49-307.1 ng/mL. The established method is highly specific for Cry1Ab recognition, with negligible cross-reactivity for other Cry toxins. For spiked cereal samples, the recoveries of Cry1Ab toxin ranged from 77.4% to 127%, with coefficient of variation of less than 9%. This study demonstrated that the competitive format based on phage-displayed anti-idiotypic nanobodies can provide an alternative strategy for Cry toxin detection.
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Elucidation of amyloid beta-protein oligomerization mechanisms: discrete molecular dynamics study.
Urbanc, B; Betnel, M; Cruz, L; Bitan, G; Teplow, D B
2010-03-31
Oligomers of amyloid beta-protein (Abeta) play a central role in the pathology of Alzheimer's disease. Of the two predominant Abeta alloforms, Abeta(1-40) and Abeta(1-42), Abeta(1-42) is more strongly implicated in the disease. We elucidated the structural characteristics of oligomers of Abeta(1-40) and Abeta(1-42) and their Arctic mutants, [E22G]Abeta(1-40) and [E22G]Abeta(1-42). We simulated oligomer formation using discrete molecular dynamics (DMD) with a four-bead protein model, backbone hydrogen bonding, and residue-specific interactions due to effective hydropathy and charge. For all four peptides under study, we derived the characteristic oligomer size distributions that were in agreement with prior experimental findings. Unlike Abeta(1-40), Abeta(1-42) had a high propensity to form paranuclei (pentameric or hexameric) structures that could self-associate into higher-order oligomers. Neither of the Arctic mutants formed higher-order oligomers, but [E22G]Abeta(1-40) formed paranuclei with a similar propensity to that of Abeta(1-42). Whereas the best agreement with the experimental data was obtained when the charged residues were modeled as solely hydrophilic, further assembly from spherical oligomers into elongated protofibrils was induced by nonzero electrostatic interactions among the charged residues. Structural analysis revealed that the C-terminal region played a dominant role in Abeta(1-42) oligomer formation whereas Abeta(1-40) oligomerization was primarily driven by intermolecular interactions among the central hydrophobic regions. The N-terminal region A2-F4 played a prominent role in Abeta(1-40) oligomerization but did not contribute to the oligomerization of Abeta(1-42) or the Arctic mutants. The oligomer structure of both Arctic peptides resembled Abeta(1-42) more than Abeta(1-40), consistent with their potentially more toxic nature.
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Field evidence for the exposure of ground beetles to Cry1Ab from transgenic corn.
Zwahlen, Claudia; Andow, David A
2005-01-01
Non-target organisms associated with the soil might be adversely affected by exposure to the CrylAb protein from Bacillus thuringiensis (Bt) in transgenic corn (Zea mays L.). To check for such exposure, we used ELISA to test for Cry1Ab in ground beetles collected live from fields with Bt corn residues and Bt corn (Bt/Bt), Bt corn residues and non-Bt crops (Bt/non-Bt), or non-Bt corn residues and non-Bt crops (non-Bt/non-Bt). In fields with Bt corn residues (Bt/Bt and Bt/non-Bt), Cry1Ab was present in all seven species of ground beetles examined (Agonum placidum, Bembidion rupicola, Clivina impressefrons, Cyclotrachelus iowensis, Harpalus pensylvanicus, Poecilus chalcites, and Poecilus lucublandus). For the two most abundant species, P. chalcites and P. lucublandus, the proportion of beetles with Cry1Ab was significantly higher in Bt/Bt fields (0.50-1.0) and Bt/non-Bt fields (0.41-0.50) than in non-Bt/non-Bt fields (0.0). This is the first field evidence that some ground beetle species are exposed to Cry1Ab. The implications of exposure on the performance of these non-target organisms are unclear.
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Optimization of the All-D Peptide D3 for Aβ Oligomer Elimination.
Directory of Open Access Journals (Sweden)
Antonia Nicole Klein
Full Text Available The aggregation of amyloid-β (Aβ is postulated to be the crucial event in Alzheimer's disease (AD. In particular, small neurotoxic Aβ oligomers are considered to be responsible for the development and progression of AD. Therefore, elimination of thesis oligomers represents a potential causal therapy of AD. Starting from the well-characterized d-enantiomeric peptide D3, we identified D3 derivatives that bind monomeric Aβ. The underlying hypothesis is that ligands bind monomeric Aβ and stabilize these species within the various equilibria with Aβ assemblies, leading ultimately to the elimination of Aβ oligomers. One of the hereby identified d-peptides, DB3, and a head-to-tail tandem of DB3, DB3DB3, were studied in detail. Both peptides were found to: (i inhibit the formation of Thioflavin T-positive fibrils; (ii bind to Aβ monomers with micromolar affinities; (iii eliminate Aβ oligomers; (iv reduce Aβ-induced cytotoxicity; and (v disassemble preformed Aβ aggregates. The beneficial effects of DB3 were improved by DB3DB3, which showed highly enhanced efficacy. Our approach yielded Aβ monomer-stabilizing ligands that can be investigated as a suitable therapeutic strategy against AD.
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Directory of Open Access Journals (Sweden)
Jeong HR
2015-11-01
Full Text Available Hye Rin Jeong, Seong Soo A AnDepartment of Bionano Technology, Gachon Medical Research Institute, Gachon University, Gyeonggi-do, Republic of KoreaAbstract: Human islet amyloid polypeptide (h-IAPP is a peptide hormone that is synthesized and cosecreted with insulin from insulin-secreting pancreatic β-cells. Recently, h-IAPP was proposed to be the main component responsible for the cytotoxic pancreatic amyloid deposits in patients with type 2 diabetes mellitus (T2DM. Since the causative factors of IAPP (or amylin oligomer aggregation are not fully understood, this review will discuss the various forms of h-IAPP aggregation. Not all forms of IAPP aggregates trigger the destruction of β-cell function and loss of β-cell mass; however, toxic oligomers do trigger these events. Once these toxic oligomers form under abnormal metabolic conditions in T2DM, they can lead to cell disruption by inducing cell membrane destabilization. In this review, the various factors that have been shown to induce toxic IAPP oligomer formation will be presented, as well as the potential mechanism of oligomer and fibril formation from pro-IAPPs. Initially, pro-IAPPs undergo enzymatic reactions to produce the IAPP monomers, which can then develop into oligomers and fibrils. By this mechanism, toxic oligomers could be generated by diverse pathway components. Thus, the interconnections between factors that influence amyloid aggregation (eg, absence of PC2 enzyme, deamidation, reduction of disulfide bonds, environmental factors in the cell, genetic mutations, copper metal ions, and heparin will be presented. Hence, this review will aid in understanding the fundamental causative factors contributing to IAPP oligomer formation and support studies for investigating novel T2DM therapeutic approaches, such as the development of inhibitory agents for preventing oligomerization at the early stages of diabetic pathology.Keywords: amyloid aggregation, causative factor, IAPP, islet
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BROWN DWARFS IN YOUNG MOVING GROUPS FROM PAN-STARRS1. I. AB DORADUS
Energy Technology Data Exchange (ETDEWEB)
Aller, Kimberly M.; Liu, Michael C.; Magnier, Eugene A.; Best, William M. J.; Kotson, Michael C.; Burgett, William S.; Chambers, Kenneth C.; Hodapp, Klaus W.; Flewelling, Heather; Kaiser, Nick; Tonry, John L.; Wainscoat, Richard J.; Waters, Christopher [University of Hawaii, Institute of Astronomy, 2860 Woodlawn Drive, Honolulu, HI 96822 (United States); Metcalf, Nigel [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)
2016-04-20
Substellar members of young (≲150 Myr) moving groups are valuable benchmarks to empirically define brown dwarf evolution with age and to study the low-mass end of the initial mass function. We have combined Pan-STARRS1 (PS1) proper motions with optical–IR photometry from PS1, Two Micron All Sky Survey (2MASS), and WISE to search for substellar members of the AB Dor Moving Group within ≈50 pc and with spectral types of late M to early L, corresponding to masses down to ≈30 M {sub Jup} at the age of the group (≈125 Myr). Including both photometry and proper motions allows us to better select candidates by excluding field dwarfs whose colors are similar to young AB Dor Moving Group members. Our near-IR spectroscopy has identified six ultracool dwarfs (M6–L4; ≈30–100 M {sub Jup}) with intermediate surface gravities (int-g) as candidate members of the AB Dor Moving Group. We find another two candidate members with spectra showing hints of youth but consistent with field gravities. We also find four field brown dwarfs unassociated with the AB Dor Moving Group, three of which have int-g gravity classification. While signatures of youth are present in the spectra of our ≈125 Myr objects, neither their J – K nor W 1 – W 2 colors are significantly redder than field dwarfs with the same spectral types, unlike younger ultracool dwarfs. We also determined PS1 parallaxes for eight of our candidates and one previously identified AB Dor Moving Group candidate. Although radial velocities (and parallaxes, for some) are still needed to fully assess membership, these new objects provide valuable insight into the spectral characteristics and evolution of young brown dwarfs.
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Dynamics in coarse-grained models for oligomer-grafted silica nanoparticles
Hong, Bingbing
2012-01-01
Coarse-grained models of poly(ethylene oxide) oligomer-grafted nanoparticles are established by matching their structural distribution functions to atomistic simulation data. Coarse-grained force fields for bulk oligomer chains show excellent transferability with respect to chain lengths and temperature, but structure and dynamics of grafted nanoparticle systems exhibit a strong dependence on the core-core interactions. This leads to poor transferability of the core potential to conditions different from the state point at which the potential was optimized. Remarkably, coarse graining of grafted nanoparticles can either accelerate or slowdown the core motions, depending on the length of the grafted chains. This stands in sharp contrast to linear polymer systems, for which coarse graining always accelerates the dynamics. Diffusivity data suggest that the grafting topology is one cause of slower motions of the cores for short-chain oligomer-grafted nanoparticles; an estimation based on transition-state theory shows the coarse-grained core-core potential also has a slowing-down effect on the nanoparticle organic hybrid materials motions; both effects diminish as grafted chains become longer. © 2012 American Institute of Physics.
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Interchain interactions in charged diacetylenic oligomers carrying bulk substituents revisited
International Nuclear Information System (INIS)
Ottonelli, M.; Izzo, G.M.M.; Comoretto, D.; Musso, G.F.; Dellepiane, G.
2006-01-01
We are studying how the electronic properties of an aggregate, built with conjugated oligomers carrying bulk substituents, are affected by intermolecular interactions. In this paper we apply the CEO (Collective Electronic Oscillator) method, on the basis of the semiempirical INDO/S Hamiltonian, to compute the electronic density matrix modifications following the photon absorption in a doubly charged cluster of two units of a fully carbazolyl-substituted oligodiacetylene tetramer, taken as a model system. The picture that had emerged from our previous calculations based on the less sophisticated CIS (Configuration Interaction including Singles) approach is seen to be confirmed. Despite the large separation between the backbones, a through-space charge transfer occurs between the two oligomers due to the fact that the excess charge, contrary to what is generally believed, is not localized on the conjugated backbone, but is spread out over the carbazolyl moieties of the charged molecule. Consideration of this kind of interaction improves the theoretical results obtained for the isolated charged oligomer chain, and aids in better explaining some features of the experimental photoinduced spectra of the corresponding polymer
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International Nuclear Information System (INIS)
Zichova, M.; Vodak, M.; Kostrhun, L.; Nadvornik, V.; Stransky, J.
1986-01-01
A group of 24 patients with acute viral hepatitis B was assessed for specific antibodies against the ''core'' antigen class IgM (HB c AB IgM) during 1st-4th week of the illness. These specific antibodies were positive in all patients, the mean titre being 10 -5 . The high content of these antibodies persisted for 1-2 months after the onset of the disease. The assessment of specific antibodies against ''core'' antigen class IgM was also made in a group of 39 patients with chronic hepatitis. In these patients positive HB c Ab IgM with a lower content were found (titre 10 -3 ) than in the group with acute viral hepatitis B. Based on the results the conclusion is made that specific antibodies HB c Ab class IgM are, in addition to the estimation of the surface antigen of the hepatitis B virus (HB s Ag), one more indicator of acute viral hepatitis B. The assessment is diagnostically valuable, in particular in acute hepatitis of obscure etiology, in acute jaundice of obscure etiology for the period of low and short-term antigenemia. (author). 6 figs., 1 tab., 14 refs
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Lack of evidence of CD40 ligand involvement in transfusion-related acute lung injury
Tuinman, P. R.; Gerards, M. C.; Jongsma, G.; Vlaar, A. P.; Boon, L.; Juffermans, N. P.
2011-01-01
Activated platelets have been implicated in playing a major role in transfusion-related acute lung injury (TRALI), as platelets can trigger neutrophils, resulting in vascular damage. We hypothesized that binding of platelet CD40 ligand (CD40L) to endothelial CD40 is essential in the onset of TRALI.
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Moriyama, Kenji; Yoshizawa-Sugata, Naoko; Masai, Hisao
2018-03-09
Rap1-interacting protein 1 (Rif1) regulates telomere length in budding yeast. We previously reported that, in metazoans and fission yeast, Rif1 also plays pivotal roles in controlling genome-wide DNA replication timing. We proposed that Rif1 may assemble chromatin compartments that contain specific replication-timing domains by promoting chromatin loop formation. Rif1 also is involved in DNA lesion repair, restart after replication fork collapse, anti-apoptosis activities, replicative senescence, and transcriptional regulation. Although multiple physiological functions of Rif1 have been characterized, biochemical and structural information on mammalian Rif1 is limited, mainly because of difficulties in purifying the full-length protein. Here, we expressed and purified the 2418-amino-acid-long, full-length murine Rif1 as well as its partially truncated variants in human 293T cells. Hydrodynamic analyses indicated that Rif1 forms elongated or extended homo-oligomers in solution, consistent with the presence of a HEAT-type helical repeat segment known to adopt an elongated shape. We also observed that the purified murine Rif1 bound G-quadruplex (G4) DNA with high specificity and affinity, as was previously shown for Rif1 from fission yeast. Both the N-terminal (HEAT-repeat) and C-terminal segments were involved in oligomer formation and specifically bound G4 DNA, and the central intrinsically disordered polypeptide segment increased the affinity for G4. Of note, pulldown assays revealed that Rif1 simultaneously binds multiple G4 molecules. Our findings support a model in which Rif1 modulates chromatin loop structures through binding to multiple G4 assemblies and by holding chromatin fibers together. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.
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Extended Ladder-Type Benzo[ k ]tetraphene-Derived Oligomers
Energy Technology Data Exchange (ETDEWEB)
Lee, Jongbok [Department of Chemistry, Texas A& M University, 3255 TAMU College Station TX 77843-3255 USA; Li, Huanbin [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, State Key Laboratory of Silicon Materials, Department of Polymer Science and Engineering, Zhejiang University, 38 Zheda Rd Hangzhou 310027 China; Kalin, Alexander J. [Department of Chemistry, Texas A& M University, 3255 TAMU College Station TX 77843-3255 USA; Yuan, Tianyu [Department of Materials Science and Engineering, Texas A& M University, 3003 TAMU College Station TX 77843-3003 USA; Wang, Chenxu [Department of Materials Science and Engineering, Texas A& M University, 3003 TAMU College Station TX 77843-3003 USA; Olson, Troy [Department of Chemistry, Texas A& M University, 3255 TAMU College Station TX 77843-3255 USA; Li, Hanying [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, State Key Laboratory of Silicon Materials, Department of Polymer Science and Engineering, Zhejiang University, 38 Zheda Rd Hangzhou 310027 China; Fang, Lei [Department of Chemistry, Texas A& M University, 3255 TAMU College Station TX 77843-3255 USA; Department of Materials Science and Engineering, Texas A& M University, 3003 TAMU College Station TX 77843-3003 USA
2017-10-02
Well-defined, fused-ring aromatic oligomers represent promising candidates for the fundamental understanding and application of advanced carbon-rich materials, though bottom-up synthesis and structure–property correlation of these compounds remain challenging. In this work, an efficient synthetic route was employed to construct extended benzo[k]tetraphene-derived oligomers with up to 13 fused rings. The molecular and electronic structures of these compounds were clearly elucidated. Precise correlation of molecular sizes and crystallization dynamics was established, thus demonstrating the pivotal balance between intermolecular interaction and molecular mobility for optimized processing of highly ordered solids of these extended conjugated molecules.
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Pronk, A; Yu, F; Vlaanderen, J; Tielemans, E; Preller, L; Bobeldijk, I; Deddens, J A; Latza, U; Baur, X; Heederik, D
2006-09-01
To study inhalation and dermal exposure to hexamethylene diisocyanate (HDI) and its oligomers as well as personal protection equipment (PPE) use during task performance in conjunction with urinary hexamethylene diamine (HDA) in car body repair shop workers and industrial spray painters. Personal task based inhalation samples (n = 95) were collected from six car body repair shops and five industrial painting companies using impingers with di-n-butylamine (DBA) in toluene. In parallel, dermal exposure was assessed using nitril rubber gloves. Gloves were submerged into DBA in toluene after sampling. Analysis for HDI and its oligomers was performed by LC-MS/MS. Urine samples were collected from 55 workers (n = 291) and analysed for HDA by GC-MS. Inhalation exposure was strongly associated with tasks during which aerosolisation occurs. Dermal exposure occurred during tasks that involve direct handling of paint. In car body repair shops associations were found between detectable dermal exposure and glove use (odds ratio (OR) 0.22, 95% confidence interval (CI) 0.09 to 0.57) and inhalation exposure level (OR 1.34, 95% CI 0.97 to 1.84 for a 10-fold increase). HDA in urine could be demonstrated in 36% and 10% of car body repair shop workers and industrial painting company workers respectively. In car body repair shops, the frequency of detectable HDA was significantly elevated at the end of the working day (OR 2.13, 95% CI 1.07 to 4.22 for 3-6 pm v 0-8 am). In both branches HDA was detected in urine of approximately 25% of the spray painters. In addition HDA was detected in urine of a large proportion of non-spray painters in car body repair shops. Although (spray) painting with lacquers containing isocyanate hardeners results in the highest external exposures to HDI and oligomers, workers that do not perform paint related tasks may also receive a considerable internal dose.
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Ramirez-Romero, R; Desneux, N; Decourtye, A; Chaffiol, A; Pham-Delègue, M H
2008-06-01
Genetically modified Bt crops are increasingly used worldwide but side effects and especially sublethal effects on beneficial insects remain poorly studied. Honey bees are beneficial insects for natural and cultivated ecosystems through pollination. The goal of the present study was to assess potential effects of two concentrations of Cry1Ab protein (3 and 5000 ppb) on young adult honey bees. Following a complementary bioassay, our experiments evaluated effects of the Cry1Ab on three major life traits of young adult honey bees: (a) survival of honey bees during sub-chronic exposure to Cry1Ab, (b) feeding behaviour, and (c) learning performance at the time that honey bees become foragers. The latter effect was tested using the proboscis extension reflex (PER) procedure. The same effects were also tested using a chemical pesticide, imidacloprid, as positive reference. The tested concentrations of Cry1Ab protein did not cause lethal effects on honey bees. However, honey bee feeding behaviour was affected when exposed to the highest concentration of Cry1Ab protein, with honey bees taking longer to imbibe the contaminated syrup. Moreover, honey bees exposed to 5000 ppb of Cry1Ab had disturbed learning performances. Honey bees continued to respond to a conditioned odour even in the absence of a food reward. Our results show that transgenic crops expressing Cry1Ab protein at 5000 ppb may affect food consumption or learning processes and thereby may impact honey bee foraging efficiency. The implications of these results are discussed in terms of risks of transgenic Bt crops for honey bees.
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Excitations and optical properties of phenylene-based conjugated polymers and oligomers
Brazovskii, S.; Kirova, N.; Bishop, A. R.; Klimov, V.; McBranch, D.; Barashkov, N. N.; Ferraris, J. P.
1998-01-01
We present a combined experimental and theoretical study of the ground and photoexcited optical properties of a model oligomer of PPV, MEH-DSB. Our theoretical picture is based upon a band description of electronic states of PPV oligomers, while invoking corrections from Coulomb interactions. The necessary discrete energy levels at low and intermediate energies appear naturally, in addition to the lower energy delocalized states. On this basis we identify the most important features in direct optical absorption for both high (4-6 eV) and low (2-4 eV) photon energies as well as in photoinduced absorption (PA) and stimulated photoemissions (SE) in MEH-DSB solutions, which represent the limit of noninteracting oligomers. While in agreement with previous interpretations for three absorption peaks (2.74, 4.46 and 6.2 eV), we give a new assignment for the most disputed 3.62 eV one as well as for the two PA peaks.
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Clinical significance of determination of serum leptin and AsAb, EmAb levels in infertile women
International Nuclear Information System (INIS)
Luo Jian; Zhou Minglian; Sun Gang; He Haoming
2010-01-01
Objective: To study the clinical significance of determination of serum leptin, AsAb, and EmAb levels in infertile women. Methods: Serum leptin (with RIA) and AsAb, EmAb (with ELISA) levels were detected in 32 infertile women and 35 controls. Results: Serum leptin levels in infertile women were significantly lower than those in controls (P<0.01). Serum AsAb and EmAb were both positive in 25 of the 32 infertile women (78.1%) and EmAb (one of two Abs) was positive in the rest 7 women (21.9%). These positive rates were also significantly higher than the respective ones in the controls (both P<0.01). Conclusion: Lower serum leptin level with highly positive AsAb and EmAb might be the chief cause of infertility in women. (authors)
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Radioimmunotherapy of human colon cancer xenografts by using 131I labeled-CAb1 F(ab')2
International Nuclear Information System (INIS)
Li Ling; Xu Huiyun; Mi Li; Bian Huijie; Qin Jun; Xiong Hua; Feng Qiang; Wen Ning; Tian Rong; Xu Liqing; Shen Xiaomei; Tang Hao; Chen Zhinan
2006-01-01
Purpose: Therapeutic efficacy, suitable dose, and administration times of 131 I-CAb 1 F(ab') 2 , a new monoclonal antibody therapeutics specifically directed against a cell surface-associated glycoprotein of colon cancer, were investigated in this article. Methods and Materials: In human colon cancer xenografts, 131 I-CAb 1 F(ab') 2 at the dose of 125 μCi, 375 μCi, and 1125 μCi were administrated intraperitoneally on Days 6 and 18 after implantation of HR8348 cells with CAb 1 high reactivity. Survival time and tumor growth inhibition rate were used to evaluate the efficacy and safety of 131 I-CAb 1 F(ab') 2 in treatment of colon cancer xenografts. Results: Treatment of 125, 375, and 1125 μCi 131 I-CAb1 F(ab') 2 did not significantly decrease the mean survival time of nude mice when compared with nontreated groups (p = 0.276, 0.865, 0.582, respectively). Moreover, the mean survival times of nude mice receiving 375 μCi and 1125 μCi 131 I-CAb1 F(ab') 2 were significantly longer than that of 5-FU-treated groups (p 0.018 and 0.042). Tumor growth inhibition rates of the first therapy were 35.67% and 41.37%, with corresponding 131 I-labeled antibody dosage of 375 μCi and 1125 μCi. After single attack dosage, second reinforcement therapy may rise efficacy significantly. Tumor growth inhibition rates of 125 μCi, 375 μCi, and 1125 μCi 131 I-labeled antibody on Day 20 posttherapy were 42.65%, 56.56%, and 84.41%, respectively. Histopathology examination revealed that tissue necrosis of various degrees was found in 131 I-CAb1 F(ab') 2 -treated groups. Conclusion: 131 I-CAb 1 F(ab') 2 is safe and effective for colon cancer. It may be a novel and potentially adjuvant therapeutics for colon cancer
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Directory of Open Access Journals (Sweden)
Xing Y
2017-04-01
Full Text Available Yun Xing,1,2 Xiao-Zhen Feng,2 Lipeng Zhang,1 Jiating Hou,2 Guo-Cheng Han,2 Zhencheng Chen2 1Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, 2School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, People’s Republic of China Abstract: Soluble beta-amyloid (Aβ oligomer is believed to be the most important toxic species in the brain of Alzheimer’s disease (AD patients. Thus, it is critical to develop a simple method for the selective detection of Aβ oligomer with low cost and high sensitivity. In this paper, we report an electrochemical method for the detection of Aβ oligomer with a peptide as the bioreceptor and silver nanoparticle (AgNP aggregates as the redox reporters. This strategy is based on the conversion of AgNP-based colorimetric assay into electrochemical analysis. Specifically, the peptide immobilized on the electrode surface and presented in solution triggered together the in situ formation of AgNP aggregates, which produced a well-defined electrochemical signal. However, the specific binding of Aβ oligomer to the immobilized peptide prevented the in situ assembly of AgNPs. As a result, a poor electrochemical signal was observed. The detection limit of the method was found to be 6 pM. Furthermore, the amenability of this method for the analysis of Aβ oligomer in serum and artificial cerebrospinal fluid (aCSF samples was demonstrated. Keywords: electrochemical biosensors, Alzheimer’s disease, beta-amyloid oligomer, peptide, silver nanoparticles
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2010-07-01
... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Information for Waste Management Units... Subpart G of Part 63—Information for Waste Management Units To Be Submitted With Notification of Compliance Status a,b Waste management unit identification c Description d Wastewater stream(s) received or...
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Roche, Julien; Shen, Yang; Lee, Jung Ho; Ying, Jinfa; Bax, Ad
2016-02-09
The pathogenesis of Alzheimer's disease is characterized by the aggregation and fibrillation of amyloid peptides Aβ(1-40) and Aβ(1-42) into amyloid plaques. Despite strong potential therapeutic interest, the structural pathways associated with the conversion of monomeric Aβ peptides into oligomeric species remain largely unknown. In particular, the higher aggregation propensity and associated toxicity of Aβ(1-42) compared to that of Aβ(1-40) are poorly understood. To explore in detail the structural propensity of the monomeric Aβ(1-40) and Aβ(1-42) peptides in solution, we recorded a large set of nuclear magnetic resonance (NMR) parameters, including chemical shifts, nuclear Overhauser effects (NOEs), and J couplings. Systematic comparisons show that at neutral pH the Aβ(1-40) and Aβ(1-42) peptides populate almost indistinguishable coil-like conformations. Nuclear Overhauser effect spectra collected at very high resolution remove assignment ambiguities and show no long-range NOE contacts. Six sets of backbone J couplings ((3)JHNHα, (3)JC'C', (3)JC'Hα, (1)JHαCα, (2)JNCα, and (1)JNCα) recorded for Aβ(1-40) were used as input for the recently developed MERA Ramachandran map analysis, yielding residue-specific backbone ϕ/ψ torsion angle distributions that closely resemble random coil distributions, the absence of a significantly elevated propensity for β-conformations in the C-terminal region of the peptide, and a small but distinct propensity for αL at K28. Our results suggest that the self-association of Aβ peptides into toxic oligomers is not driven by elevated propensities of the monomeric species to adopt β-strand-like conformations. Instead, the accelerated disappearance of Aβ NMR signals in D2O over H2O, particularly pronounced for Aβ(1-42), suggests that intermolecular interactions between the hydrophobic regions of the peptide dominate the aggregation process.
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Xing, Fuguo; Zhang, Wei; Selvaraj, Jonathan Nimal; Liu, Yang
2015-05-01
Food processing methods contribute to DNA degradation, thereby affecting genetically modified organism detection and quantification. This study evaluated the effect of food processing methods on the relative transgenic content of genetically modified rice with Cry1Ab. In steamed rice and rice noodles, the levels of Cry1Ab were ⩾ 100% and <83%, respectively. Frying and baking in rice crackers contributed to a reduction in Pubi and Cry1Ab, while microwaving caused a decrease in Pubi and an increase in Cry1Ab. The processing methods of sweet rice wine had the most severe degradation effects on Pubi and Cry1Ab. In steamed rice and rice noodles, Cry1Ab was the most stable, followed by SPS and Pubi. However, in rice crackers and sweet rice wine, SPS was the most stable, followed by Cry1Ab and Pubi. Therefore, Cry1Ab is a better representative of transgenic components than is Pubi because the levels of Cry1Ab were less affected compared to Pubi. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Langen Ralf
2008-10-01
Full Text Available Abstract Background The multifunctional protein vitronectin is present within the deposits associated with Alzheimer disease (AD, age-related macular degeneration (AMD, atherosclerosis, systemic amyloidoses, and glomerulonephritis. The extent to which vitronectin contributes to amyloid formation within these plaques, which contain misfolded, amyloidogenic proteins, and the role of vitronectin in the pathophysiology of the aforementioned diseases is currently unknown. The investigation of vitronectin aggregation is significant since the formation of oligomeric and fibrillar structures are common features of amyloid proteins. Results We observed vitronectin immunoreactivity in senile plaques of AD brain, which exhibited overlap with the amyloid fibril-specific OC antibody, suggesting that vitronectin is deposited at sites of amyloid formation. Of particular interest is the growing body of evidence indicating that soluble nonfibrillar oligomers may be responsible for the development and progression of amyloid diseases. In this study we demonstrate that both plasma-purified and recombinant human vitronectin readily form spherical oligomers and typical amyloid fibrils. Vitronectin oligomers are toxic to cultured neuroblastoma and retinal pigment epithelium (RPE cells, possibly via a membrane-dependent mechanism, as they cause leakage of synthetic vesicles. Oligomer toxicity was attenuated in RPE cells by the anti-oligomer A11 antibody. Vitronectin fibrils contain a C-terminal protease-resistant fragment, which may approximate the core region of residues essential to amyloid formation. Conclusion These data reveal the propensity of vitronectin to behave as an amyloid protein and put forth the possibilities that accumulation of misfolded vitronectin may contribute to aggregate formation seen in age-related amyloid diseases.
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Hernández-Rodríguez, Carmen Sara; Hernández-Martínez, Patricia; Van Rie, Jeroen; Escriche, Baltasar; Ferré, Juan
2013-01-01
First generation of insect-protected transgenic corn (Bt-corn) was based on the expression of Cry1Ab or Cry1Fa proteins. Currently, the trend is the combination of two or more genes expressing proteins that bind to different targets. In addition to broadening the spectrum of action, this strategy helps to delay the evolution of resistance in exposed insect populations. One of such examples is the combination of Cry1A.105 with Cry1Fa and Cry2Ab to control O. nubilalis and S. frugiperda. Cry1A.105 is a chimeric protein with domains I and II and the C-terminal half of the protein from Cry1Ac, and domain III almost identical to Cry1Fa. The aim of the present study was to determine whether the chimeric Cry1A.105 has shared binding sites either with Cry1A proteins, with Cry1Fa, or with both, in O. nubilalis and in S. frugiperda. Brush-border membrane vesicles (BBMV) from last instar larval midguts were used in competition binding assays with 125I-labeled Cry1A.105, Cry1Ab, and Cry1Fa, and unlabeled Cry1A.105, Cry1Aa, Cry1Ab, Cry1Ac, Cry1Fa, Cry2Ab and Cry2Ae. The results showed that Cry1A.105, Cry1Ab, Cry1Ac and Cry1Fa competed with high affinity for the same binding sites in both insect species. However, Cry2Ab and Cry2Ae did not compete for the binding sites of Cry1 proteins. Therefore, according to our results, the development of cross-resistance among Cry1Ab/Ac, Cry1A.105, and Cry1Fa proteins is possible in these two insect species if the alteration of shared binding sites occurs. Conversely, cross-resistance between these proteins and Cry2A proteins is very unlikely in such case. PMID:23861865
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Energy Technology Data Exchange (ETDEWEB)
Zichova, M; Vodak, M; Kostrhun, L; Nadvornik, V; Stransky, J
1987-12-31
A group of 24 patients with acute viral hepatitis B was assessed for specific antibodies against the ''core'' antigen class IgM (HB/sub c/AB IgM) during 1st-4th week of the illness. These specific antibodies were positive in all patients, the mean titre being 10/sup -5/. The high content of these antibodies persisted for 1-2 months after the onset of the disease. The assessment of specific antibodies against ''core'' antigen class IgM was also made in a group of 39 patients with chronic hepatitis. In these patients positive HB/sub c/Ab IgM with a lower content were found (titre 10/sup -3/) than in the group with acute viral hepatitis B. Based on the results the conclusion is made that specific antibodies HB/sub c/Ab class IgM are, in addition to the estimation of the surface antigen of the hepatitis B virus (HB/sub s/Ag), one more indicator of acute viral hepatitis B. The assessment is diagnostically valuable, in particular in acute hepatitis of obscure etiology, in acute jaundice of obscure etiology for the period of low and short-term antigenemia. (author). 6 figs., 1 tab., 14 refs.
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α-Synuclein oligomers and clinical implications for Parkinson disease
Kalia, Lorraine V.; Kalia, Suneil K.; McLean, Pamela J.; Lozano, Andres M.; Lang, Anthony E.
2012-01-01
Protein aggregation within the central nervous system has been recognized as a defining feature of neurodegenerative diseases since the early 20th century. Since that time, there has been a growing list of neurodegenerative disorders, including Parkinson disease, which are characterized by inclusions of specific pathogenic proteins. This has led to the long-held dogma that these characteristic protein inclusions, which are composed of large insoluble fibrillar protein aggregates and visible by light microscopy, are responsible for cell death in these diseases. However, the correlation between protein inclusion formation and cytotoxicity is inconsistent suggesting another form of the pathogenic proteins may be contributing to neurodegeneration. There is emerging evidence implicating soluble oligomers, smaller protein aggregates not detectable by conventional microscopy, as potential culprits in the pathogenesis of neurodegenerative diseases. The protein α-synuclein is well recognized to contribute to the pathogenesis of Parkinson disease and is the major component of Lewy bodies and Lewy neurites. However, α-synuclein also forms oligomeric species with certain conformations being toxic to cells. The mechanisms by which these α-synuclein oligomers cause cell death are being actively investigated as they may provide new strategies for diagnosis and treatment of Parkinson disease and related disorders. Here we review the possible role of α-synuclein oligomers in cell death in Parkinson disease and discuss the potential clinical implications. PMID:23225525
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International Nuclear Information System (INIS)
Yuan, Yiyang; Krogh, Paul Henning; Bai, Xue; Roelofs, Dick; Chen, Fajun; Zhu-Salzman, Keyan; Liang, Yuyong; Sun, Yucheng; Ge, Feng
2014-01-01
The impact of Bt proteins on non-target arthropods is less understood than their effects on target organisms where the mechanism of toxic action is known. Here, we report the effects of two Bt proteins, Cry1Ab and Cry1Ac, on gene expression in the non-target collembolan, Folsomia candida. A customized microarray was used to study gene expression in F. candida specimens that were exposed to Cry1Ab and Cry1Ac. All selected transcripts were subsequently confirmed by qPCR. Eleven transcripts were finally verified, and three of them were annotated. The responses of all eleven transcripts were tested in specimens for both Cry1Ab and Cry1Ac at a series of concentrations. These transcripts were separated into two and three groups for Cry1Ab and Cry1Ac, respectively, depend on their expression levels. However, those eleven transcripts did not respond to the Bt proteins in Bt-rice residues. -- Highlights: • We examined the effects of Bt proteins on gene expression of Folsomia candida. • Eleven transcripts were up-regulated by Bt proteins (Cry1Ab and Cry1Ac). • Only three of the eleven transcripts were annotated. • The responses of 11 transcripts were tested on both Cry1Ab and Cry1Ac. • These transcripts did not respond to the Bt proteins in Bt-rice residues. -- Eleven potential molecular biomarkers of Folsomia candida to Cry1Ab and Cry1Ac were screened by microarray and qPCR analysis
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Pronk, A; Yu, F; Vlaanderen, J; Tielemans, E; Preller, L; Bobeldijk, I; Deddens, J A; Latza, U; Baur, X; Heederik, D
2006-01-01
Objectives To study inhalation and dermal exposure to hexamethylene diisocyanate (HDI) and its oligomers as well as personal protection equipment (PPE) use during task performance in conjunction with urinary hexamethylene diamine (HDA) in car body repair shop workers and industrial spray painters. Methods Personal task based inhalation samples (n = 95) were collected from six car body repair shops and five industrial painting companies using impingers with di‐n‐butylamine (DBA) in toluene. In parallel, dermal exposure was assessed using nitril rubber gloves. Gloves were submerged into DBA in toluene after sampling. Analysis for HDI and its oligomers was performed by LC‐MS/MS. Urine samples were collected from 55 workers (n = 291) and analysed for HDA by GC‐MS. Results Inhalation exposure was strongly associated with tasks during which aerosolisation occurs. Dermal exposure occurred during tasks that involve direct handling of paint. In car body repair shops associations were found between detectable dermal exposure and glove use (odds ratio (OR) 0.22, 95% confidence interval (CI) 0.09 to 0.57) and inhalation exposure level (OR 1.34, 95% CI 0.97 to 1.84 for a 10‐fold increase). HDA in urine could be demonstrated in 36% and 10% of car body repair shop workers and industrial painting company workers respectively. In car body repair shops, the frequency of detectable HDA was significantly elevated at the end of the working day (OR 2.13, 95% CI 1.07 to 4.22 for 3–6 pm v 0–8 am). In both branches HDA was detected in urine of ∼25% of the spray painters. In addition HDA was detected in urine of a large proportion of non‐spray painters in car body repair shops. Conclusion Although (spray) painting with lacquers containing isocyanate hardeners results in the highest external exposures to HDI and oligomers, workers that do not perform paint related tasks may also receive a considerable internal dose. PMID:16728504
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Rescue of failed filtering blebs with ab interno trephination.
Shihadeh, Wisam A; Ritch, Robert; Liebmann, Jeffrey M
2006-06-01
We evaluated the effectiveness of ab interno automated trephination as a technique for rescuing failed mature filtering blebs. A retrospective chart review of 40 failed blebs of 38 patients who had a posttrephination follow-up period of at least 3 months was done. With success defined as intraocular pressure (IOP) control with other modalities of management. Complications were few. We believe that ab interno trephination is an excellent option for rescuing selected failed filtering blebs.
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Directory of Open Access Journals (Sweden)
Maria C Walsh
Full Text Available BACKGROUND: The objective of this study was to evaluate potential long-term (110 days and age-specific effects of feeding genetically modified Bt maize on peripheral immune response in pigs and to determine the digestive fate of the cry1Ab gene and truncated Bt toxin. METHODOLOGY/PRINCIPAL FINDINGS: Forty day old pigs (n = 40 were fed one of the following treatments: 1 isogenic maize-based diet for 110 days (isogenic; 2 Bt maize-based diet (MON810 for 110 days (Bt; 3 Isogenic maize-based diet for 30 days followed by Bt maize-based diet for 80 days (isogenic/Bt; and 4 Bt maize-based diet (MON810 for 30 days followed by isogenic maize-based diet for 80 days (Bt/isogenic. Blood samples were collected during the study for haematological analysis, measurement of cytokine and Cry1Ab-specific antibody production, immune cell phenotyping and cry1Ab gene and truncated Bt toxin detection. Pigs were sacrificed on day 110 and digesta and organ samples were taken for detection of the cry1Ab gene and the truncated Bt toxin. On day 100, lymphocyte counts were higher (P<0.05 in pigs fed Bt/isogenic than pigs fed Bt or isogenic. Erythrocyte counts on day 100 were lower in pigs fed Bt or isogenic/Bt than pigs fed Bt/isogenic (P<0.05. Neither the truncated Bt toxin nor the cry1Ab gene were detected in the organs or blood of pigs fed Bt maize. The cry1Ab gene was detected in stomach digesta and at low frequency in the ileum but not in the distal gastrointestinal tract (GIT, while the Bt toxin fragments were detected at all sites in the GIT. CONCLUSIONS/SIGNIFICANCE: Perturbations in peripheral immune response were thought not to be age-specific and were not indicative of Th 2 type allergenic or Th 1 type inflammatory responses. There was no evidence of cry1Ab gene or Bt toxin translocation to organs or blood following long-term feeding.
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Liang, Bin; Wang, Xin; Song, Xiaosu; Bai, Rui; Yang, Huiyu; Yang, Zhiming; Xiao, Chuanshi; Bian, Yunfei
2017-09-01
ATP-binding cassette transporter A1 (ABCA1) plays a crucial role in reverse cholesterol transport and exhibits anti-atherosclerosis effects. Some microRNAs (miRs) regulate ABCA1 expression, and recent studies have shown that miR-20a/b might play a critical role in atherosclerotic diseases. Here, we attempted to clarify the potential contribution of miR-20a/b in post-transcriptional regulation of ABCA1, cholesterol efflux, and atherosclerosis. We performed bioinformatics analysis and found that miR-20a/b was highly conserved and directly bound to ABCA1 mRNA with low binding free energy. Luciferase-reporter assay also confirmed that miR-20a/b significantly reduced luciferase activity associated with the ABCA1 3' untranslated region reporter construct. Additionally, miR-20a/b decreased ABCA1 expression, which, in turn, decreased cholesterol efflux and increased cholesterol content in THP-1 and RAW 264.7 macrophage-derived foam cells. In contrast, miR-20a/b inhibitors increased ABCA1 expression and cholesterol efflux, decreased cholesterol content, and inhibited foam-cell formation. Consistent with our in vitro results, miR-20a/b-treated ApoE -/- mice showed decreased ABCA1expression in the liver and reductions of reverse cholesterol transport in vivo. Furthermore, miR-20a/b regulated the formation of nascent high-density lipoprotein and promoted atherosclerotic development, whereas miR-20a/b knockdown attenuated atherosclerotic formation. miR-20 is a new miRNA capable of targeting ABCA1 and regulating ABCA1 expression. Therefore, miR-20 inhibition constitutes a new strategy for ABCA1-based treatment of atherosclerosis. Copyright © 2017 Elsevier B.V. All rights reserved.
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Organic heterostructures based on arylenevinylene oligomers deposited by MAPLE
Czech Academy of Sciences Publication Activity Database
Socol, M.; Preda, N.; Vacareanu, L.; Grigoras, M.; Socol, G.; Mihailescu, I. N.; Stanculescu, F.; Jelínek, Miroslav; Stanculescu, A.; Stoicanescu, M.
2014-01-01
Roč. 302, May (2014), s. 216-222 ISSN 0169-4332 Institutional support: RVO:68378271 Keywords : organic heterostructures * MAPLE * oligomer * optoelectronica Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.711, year: 2014
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Remoroza, C; Cord-Landwehr, S; Leijdekkers, A G M; Moerschbacher, B M; Schols, H A; Gruppen, H
2012-09-01
The combined action of endo-polygalacturonase (endo-PGII), pectin lyase (PL), pectin methyl esterase (fungal PME) and RG-I degrading enzymes enabled the extended degradation of methylesterified and acetylated sugar beet pectins (SBPs). The released oligomers were separated, identified and quantified using hydrophilic interaction liquid chromatography (HILIC) with online electrospray ionization ion trap mass spectrometry (ESI-IT-MS(n)) and evaporative light scattering detection (ELSD). By MS(n), the structures of galacturonic acid (GalA) oligomers having an acetyl group in the O-2 and/or O-3 positions eluting from the HILIC column were elucidated. The presence of methylesterified and/or acetylated galacturonic acid units within an oligomer reduced the interaction with the HILIC column significantly compared to the unsubstituted GalA oligomers. The HILIC column enables a good separation of most oligomers present in the digest. The use of ELSD to quantify oligogalacturonides was validated using pure GalA standards and the signal was found to be independent of the chemical structure of the oligomer being detected. The combination of chromatographic and enzymatic strategies enables to distinguish SBPs having different methylesters and acetyl group distribution. Copyright © 2012 Elsevier Ltd. All rights reserved.
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New strategy for stable-isotope-aided, multidimensional NMR spectroscopy of DNA oligomers
Energy Technology Data Exchange (ETDEWEB)
Ono, Okira; Tate, Shin-Ichi; Kainosho, Masatsune [Tokyo Metropolitan Univ., Tokyo (Japan)
1994-12-01
Nuclear Magnetic Resonance (NMR) is the most efficient method for determining the solution structures of biomolecules. By applying multidimensional heteronuclear NMR techniques to {sup 13}C/{sup 15}N-labeled proteins, we can determine the solution structures of proteins with molecular mass of 20 to 30kDa at an accuracy similar to that of x-ray crystallography. Improvements in NMR instrumentation and techniques as well as the development of protein engineering methods for labeling proteins have rapidly advanced multidimensional heteronuclear NMR of proteins. In contrast, multidimensional heteronuclear NMR studies of nucleic acids is less advanced because there were no efficient methods for preparing large amounts of labeled DNA/RNA oligomers. In this report, we focused on the chemical synthesis of DNA oligomers labeled at specific residue(s). RNA oligomers with specific labels, which are difficult to synthesize by the enzyme method, can be synthesized by the chemical method. The specific labels are useful for conformational analysis of larger molecules such as protein-nucleic acid complexes.
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Diode laser surgery. Ab interno and ab externo versus conventional surgery in rabbits.
Karp, C L; Higginbotham, E J; Edward, D P; Musch, D C
1993-10-01
Fibroblastic proliferation of subconjunctival tissues remains a primary mechanism of failure in filtration surgery. Minimizing the surgical manipulation of episcleral tissues may reduce scarring. Laser sclerostomy surgery involves minimal tissue dissection, and is gaining attention as a method of potentially improving filter duration in high-risk cases. Twenty-five New Zealand rabbits underwent filtration surgery in one eye, and the fellow eye remained as the unoperated control. Ten rabbits underwent ab externo diode laser sclerostomy surgery, ten underwent ab interno diode sclerostomy surgery, and five had posterior sclerostomy procedures. Filtration failure was defined as a less-than-4-mmHg intraocular pressure (IOP) difference between the operative and control eyes. The mean time to failure for the ab externo, ab interno, and conventional posterior sclerostomy techniques measured 17.4 +/- 11.5, 13.1 +/- 6.7, and 6.0 +/- 3.1 days, respectively. In a comparison of the laser-treated groups with the conventional procedure, the time to failure was significantly longer (P = 0.02) for the ab externo filter. The mean ab interno sclerostomy duration was longer than the posterior lip procedure, but this difference was not statistically significant (P = 0.15). The overall level of IOP reduction was similar in the three groups. These data suggest that diode laser sclerostomy is a feasible technique in rabbits, and the ab externo approach resulted in longer filter duration than the conventional posterior lip procedure in this model.
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Andreassen, Monica; Bøhn, Thomas; Wikmark, Odd-Gunnar; Bodin, Johanna; Traavik, Terje; Løvik, Martinus; Nygaard, Unni Cecilie
2016-05-04
In genetically modified (GM) crops there is a risk that the inserted genes may introduce new allergens and/or adjuvants into the food and feed chain. The MON810 maize, expressing the insecticidal Cry1Ab toxin, is grown in many countries worldwide. In animal models, intranasal and intraperitoneal immunisations with the purified Cry1Ab proteins have induced immune responses, and feeding trials with Cry1Ab-containing feed have revealed some altered immune responses. Previous investigations have primarily measured antibody responses to the protein, while investigations of clinical food allergy symptoms, or allergy promotion (adjuvant effect) associated with the Cry1Ab protein are largely missing. We aimed to investigate immunogenic, allergenic and adjuvant properties of purified Cry1Ab toxin (trypCry1Ab, i.e., trypsin activated Cry1Ab) in a mouse model of food allergy. Female C3H/HeJ mice were immunized by intragastric gavage of 10 μg purified, trypsin activated Cry1Ab toxin (trypCry1Ab) alone or together with the food allergen lupin. Cholera toxin was added as a positive control for adjuvant effect to break oral tolerance. Clinical symptoms (anaphylaxis) as well as humoral and cellular responses were assessed. In contrast to results from previous airway investigations, we observed no indication of immunogenic properties of trypCry1Ab protein after repeated intragastric exposures to one dose, with or without CT as adjuvant. Moreover, the results indicated that trypCry1Ab given by the intragastric route was not able to promote allergic responses or anaphylactic reactions against the co-administered allergen lupin at the given dose. The study suggests no immunogenic, allergenic or adjuvant capacity of the given dose of trypCry1Ab protein after intragastric exposure of prime aged mice.
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Mishra, Ashish K.
Investigating quaternary structure (oligomerization) of macromolecules (such as proteins and nucleic acids) in living systems (in vivo) has been a great challenge in biophysics, due to molecular diffusion, fluctuations in several biochemical parameters such as pH, quenching of fluorescence by oxygen (when fluorescence methods are used), etc. We studied oligomerization of membrane receptors in living cells by means of Fluorescence (Forster) Resonance Energy Transfer (FRET) using fluorescent markers and two photon excitation fluorescence micro-spectroscopy. Using suitable FRET models, we determined the stoichiometry and quaternary structure of various macromolecular complexes. The proteins of interest for this work are : (1) sigma-1 receptor and (2) rhodopsin, are described as below. (1) Sigma-1 receptors are molecular chaperone proteins, which also regulate ion channels. S1R seems to be involved in substance abuse, as well as several diseases such as Alzheimer's. We studied S1R in the presence and absence of its ligands haloperidol (an antagonist) and pentazocine +/- (an agonist), and found that at low concentration they reside as a mixture of monomers and dimers and that they may form higher order oligomers at higher concentrations. (2) Rhodopsin is a prototypical G protein coupled receptor (GPCR) and is directly involved in vision. GPCRs form a large family of receptors that participate in cell signaling by responding to external stimuli such as drugs, thus being a major drug target (more than 40% drugs target GPCRs). Their oligomerization has been largely controversial. Understanding this may help to understand the functional role of GPCRs oligomerization, and may lead to the discovery of more drugs targeting GPCR oligomers. It may also contribute toward finding a cure for Retinitis Pigmentosa, which is caused by a mutation (G188R) in rhodopsin, a disease which causes blindness and has no cure so far. Comparing healthy rhodopsin's oligomeric structure with that
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Toxic prefibrillar α-synuclein amyloid oligomers adopt a distinctive antiparallel β-sheet structure.
Celej, María Soledad; Sarroukh, Rabia; Goormaghtigh, Erik; Fidelio, Gerardo D; Ruysschaert, Jean-Marie; Raussens, Vincent
2012-05-01
Parkinson's disease is an age-related movement disorder characterized by the presence in the mid-brain of amyloid deposits of the 140-amino-acid protein AS (α-synuclein). AS fibrillation follows a nucleation polymerization pathway involving diverse transient prefibrillar species varying in size and morphology. Similar to other neurodegenerative diseases, cytotoxicity is currently attributed to these prefibrillar species rather than to the insoluble aggregates. Nevertheless, the underlying molecular mechanisms responsible for cytotoxicity remain elusive and structural studies may contribute to the understanding of both the amyloid aggregation mechanism and oligomer-induced toxicity. It is already recognized that soluble oligomeric AS species adopt β-sheet structures that differ from those characterizing the fibrillar structure. In the present study we used ATR (attenuated total reflection)-FTIR (Fourier-transform infrared) spectroscopy, a technique especially sensitive to β-sheet structure, to get a deeper insight into the β-sheet organization within oligomers and fibrils. Careful spectral analysis revealed that AS oligomers adopt an antiparallel β-sheet structure, whereas fibrils adopt a parallel arrangement. The results are discussed in terms of regions of the protein involved in the early β-sheet interactions and the implications of such conformational arrangement for the pathogenicity associated with AS oligomers.
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Hao, Mingyang; Wu, Hongwu; Qiu, Feng; Wang, Xiwen
2018-03-07
To improve the interfacial bonding of sisal fiber-reinforced polylactide biocomposites, polylactide (PLA) and sisal fibers (SF) were melt-blended to fabricate bio-based composites via in situ reactive interfacial compatibilization with addition of a commercial grade epoxy-functionalized oligomer Joncryl ADR @ -4368 (ADR). The FTIR (Fourier Transform infrared spectroscopy) analysis and SEM (scanning electron microscope) characterization demonstrated that the PLA molecular chain was bonded to the fiber surface and the epoxy-functionalized oligomer played a hinge-like role between the sisal fibers and the PLA matrix, which resulted in improved interfacial adhesion between the fibers and the PLA matrix. The interfacial reaction and microstructures of composites were further investigated by thermal and rheological analyses, which indicated that the mobility of the PLA molecular chain in composites was restricted because of the introduction of the ADR oligomer, which in turn reflected the improved interfacial interaction between SF and the PLA matrix. These results were further justified with the calculation of activation energies of glass transition relaxation (∆ E a ) by dynamic mechanical analysis. The mechanical properties of PLA/SF composites were simultaneously reinforced and toughened with the addition of ADR oligomer. The interfacial interaction and structure-properties relationship of the composites are the key points of this study.
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2015-05-08
Supplementary material for “Finding the stable structures of N1−xWX with an ab - initio high-throughput approach” Michael J. Mehl∗ Center for...AND SUBTITLE Supplementary Material for ’Finding the Stable Structures of N1-xWX with an ab - initio High-throughput Approach’ 5a. CONTRACT NUMBER 5b...and J. Hafner, Ab initio molecular dynamics for open-shell transition metals, Phys. Rev. B 48, 13115–13118 (1993). 2 G. Kresse and J. Hafner, Ab initio
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Peters, Philip J; Westheimer, Emily; Cohen, Stephanie; Hightow-Weidman, Lisa B; Moss, Nicholas; Tsoi, Benjamin; Hall, Laura; Fann, Charles; Daskalakis, Demetre C; Beagle, Steve; Patel, Pragna; Radix, Asa; Foust, Evelyn; Kohn, Robert P; Marmorino, Jenni; Pandori, Mark; Fu, Jie; Samandari, Taraz; Gay, Cynthia L
2016-02-16
Although acute HIV infection contributes disproportionately to onward HIV transmission, HIV testing has not routinely included screening for acute HIV infection. To evaluate the performance of an HIV antigen/antibody (Ag/Ab) combination assay to detect acute HIV infection compared with pooled HIV RNA testing. Multisite, prospective, within-individual comparison study conducted between September 2011 and October 2013 in 7 sexually transmitted infection clinics and 5 community-based programs in New York, California, and North Carolina. Participants were 12 years or older and seeking HIV testing, without known HIV infection. All participants with a negative rapid HIV test result were screened for acute HIV infection with an HIV Ag/Ab combination assay (index test) and pooled human immunodeficiency virus 1 (HIV-1) RNA testing. HIV RNA testing was the reference standard, with positive reference standard result defined as detectable HIV-1 RNA on an individual RNA test. Number and proportion with acute HIV infections detected. Among 86,836 participants with complete test results (median age, 29 years; 75.0% men; 51.8% men who have sex with men), established HIV infection was diagnosed in 1158 participants (1.33%) and acute HIV infection was diagnosed in 168 participants (0.19%). Acute HIV infection was detected in 134 participants with HIV Ag/Ab combination testing (0.15% [95% CI, 0.13%-0.18%]; sensitivity, 79.8% [95% CI, 72.9%-85.6%]; specificity, 99.9% [95% CI, 99.9%-99.9%]; positive predictive value, 59.0% [95% CI, 52.3%-65.5%]) and in 164 participants with pooled HIV RNA testing (0.19% [95% CI, 0.16%-0.22%]; sensitivity, 97.6% [95% CI, 94.0%-99.4%]; specificity, 100% [95% CI, 100%-100%]; positive predictive value, 96.5% [95% CI, 92.5%-98.7%]; sensitivity comparison, P testing detected 82% of acute HIV infections detectable by pooled HIV RNA testing. Compared with rapid HIV testing alone, HIV Ag/Ab combination testing increased the relative HIV diagnostic yield (both
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Enhanced Solubilization of Fluoranthene by Hydroxypropyl β-Cyclodextrin Oligomer for Bioremediation
Directory of Open Access Journals (Sweden)
Kyeong Hui Park
2018-01-01
Full Text Available Fluoranthene (FT is a polycyclic aromatic hydrocarbon (PAH, consisting of naphthalene and benzene rings connected by a five-member ring. It is widespread in the environment. The hydrophobicity of FT limits its availability for biological uptake and degradation. In this study, hydroxypropyl β-cyclodextrin oligomers (HP-β-CD-ol were synthesized with epichlorohydrin (EP, while the solubility enhancement of FT by HP-β-CD-ol was investigated in water. The synthesized HP-β-CD-ol was characterized by MALDI-TOF mass spectrometry (MS, 1H NMR, and 13C NMR spectroscopy. The solubility of FT increased 178-fold due to the complex formation with HP-β-CD oligomers. The inclusion complexes of FT/HP-β-CD-ol were analyzed using Fourier-Transform Infrared (FT-IR, Differential Scanning Calorimetry (DSC, Scanning Electron Microscope (SEM, and Nuclear Overhauser Effect Spectroscopy Nuclear magnetic resonance (NOESY NMR spectroscopy. On the basis of these results, HP-β-CD-ol is recommended as a potential solubilizer for the development of PAH removal systems.
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Synthesis and Electronic Properties of Length-Defined 9,10-Anthrylene-Butadiynylene Oligomers.
Nagaoka, Maiko; Tsurumaki, Eiji; Nishiuchi, Mai; Iwanaga, Tetsuo; Toyota, Shinji
2018-05-18
Linear π-conjugated oligomers consisting of anthracene and diacetylene units were readily synthesized by a one-pot process that involved desilylation and oxidative coupling from appropriate building units. We were able to isolate length-defined oligomers ranging from 2-mer to 6-mer as stable and soluble solids. The bathochromic shifts in the UV-vis spectra suggested that the π-conjugation was extended with elongation of the linear chain. Cyclic voltammetric measurements showed characteristic reversible oxidation waves that were dependent on the number of anthracene units.
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Chitteti, Brahmananda Reddy; Kacena, Melissa A; Voytik-Harbin, Sherry L; Srour, Edward F
2015-10-01
To recreate the in vivo hematopoietic cell microenvironment or niche and to study the impact of extracellular matrix (ECM) biophysical properties on hematopoietic progenitor cell (HPC) proliferation and function, mouse bone-marrow derived HPC (Lin-Sca1+cKit+/(LSK) were cultured within three-dimensional (3D) type I collagen oligomer matrices. To generate a more physiologic milieu, 3D cultures were established in both the presence and absence of calvariae-derived osteoblasts (OB). Collagen oligomers were polymerized at varying concentration to give rise to matrices of different fibril densities and therefore matrix stiffness (shear storage modulus, 50-800 Pa). Decreased proliferation and increased clonogenicity of LSK cells was associated with increase of matrix stiffness regardless of whether OB were present or absent from the 3D culture system. Also, regardless of whether OB were or were not added to the 3D co-culture system, LSK within 800 Pa collagen oligomer matrices maintained the highest percentage of Lin-Sca1+ cells as well as higher percentage of cells in quiescent state (G0/G1) compared to 50 Pa or 200Pa matrices. Collectively, these data illustrate that biophysical features of collagen oligomer matrices, specifically fibril density-induced modulation of matrix stiffness, provide important guidance cues in terms of LSK expansion and differentiation and therefore maintenance of progenitor cell function. Copyright © 2015. Published by Elsevier B.V.
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Afrin, Rehana; Ganbaatar, Narangerel; Aono, Masashi; Cleaves, H. James; Yano, Taka-aki; Hara, Masahiko
2018-01-01
The interaction strength of progressively longer oligomers of glycine, (Gly), di-Gly, tri-Gly, and penta-Gly, with a natural pyrite surface was directly measured using the force mode of an atomic force microscope (AFM). In recent years, selective activation of abiotically formed amino acids on mineral surfaces, especially that of pyrite, has been proposed as an important step in many origins of life scenarios. To investigate such notions, we used AFM-based force measurements to probe possible non-covalent interactions between pyrite and amino acids, starting from the simplest amino acid, Gly. Although Gly itself interacted with the pyrite surface only weakly, progressively larger unbinding forces and binding frequencies were obtained using oligomers from di-Gly to penta-Gly. In addition to an expected increase of the configurational entropy and size-dependent van der Waals force, the increasing number of polar peptide bonds, among others, may be responsible for this observation. The effect of chain length was also investigated by performing similar experiments using l-lysine vs. poly-l-lysine (PLL), and l-glutamic acid vs. poly-l-glutamic acid. The results suggest that longer oligomers/polymers of amino acids can be preferentially adsorbed on pyrite surfaces. PMID:29370126
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Yuan, Zhen; Yang, Lifeng; Chen, Baian; Zhu, Ting; Hassan, Mohammad Farooque; Yin, Xiaomin; Zhou, Xiangmei; Zhao, Deming
2015-06-01
The formation of neurotoxic prion protein (PrP) oligomers is thought to be a key step in the development of prion diseases. Recently, it was determined that the sonication and shaking of recombinant PrP can convert PrP monomers into β-state oligomers. Herein, we demonstrate that β-state oligomeric PrP can be generated through protein misfolding cyclic amplification from recombinant full-length hamster, human, rabbit, and mutated rabbit PrP, and that these oligomers can be used for subsequent research into the mechanisms of PrP-induced neurotoxicity. We have characterized protein misfolding cyclic amplification-induced monomer-to-oligomer conversion of PrP from three species using western blotting, circular dichroism, size-exclusion chromatography, and resistance to proteinase K (PK) digestion. We have further shown that all of the resulting β-oligomers are toxic to primary mouse cortical neurons independent of the presence of PrP(C) in the neurons, whereas the corresponding monomeric PrP were not toxic. In addition, we found that this toxicity is the result of oligomer-induced apoptosis via regulation of Bcl-2, Bax, and caspase-3 in both wild-type and PrP(-/-) cortical neurons. It is our hope that these results may contribute to our understanding of prion transformation within the brain. We found that β-state oligomeric PrPs can be generated through protein misfolding cyclic amplification (PMCA) from recombinant full-length hamster, human, rabbit, and mutated rabbit PrP. β-oligomers are toxic to primary mouse cortical neurons independent of the presence of PrP(C) in the neurons, while the corresponding monomeric PrPs were not toxic. This toxicity is the result of oligomers-induced apoptosis via regulation of Bcl-2, Bax, and caspase-3. These results may contribute to our understanding of prion transformation within the brain. © 2015 International Society for Neurochemistry.
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Charge transfer in conjugated oligomers encapsulated into carbon nanotubes
Energy Technology Data Exchange (ETDEWEB)
Almadori, Y.; Alvarez, L.; Michel, T.; Le Parc, R.; Bantignies, J.L.; Hermet, P.; Sauvajol, J.L. [Laboratoire Charles Coulomb UMR 5521, Universite Montpellier 2, 34095 Montpellier (France); Laboratoire Charles Coulomb UMR 5521, CNRS, 34095 Montpellier (France); Arenal, R. [Laboratoire d' Etude des Microstructures, CNRS-ONERA, 92322 Chatillon (France); Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, U. Zaragoza, 50018 Zaragoza (Spain); Babaa, R. [Laboratoire de Chimie des Surfaces et Interfaces, CEA, IRAMIS, SPCSI, 91191 Gif-sur-Yvette Cedex (France); Chemical Engineering Department, University of Technology PETRONAS, UTP, Ipoh-Perak (Malaysia); Jouselme, B.; Palacin, S. [Laboratoire de Chimie des Surfaces et Interfaces, CEA, IRAMIS, SPCSI, 91191 Gif-sur-Yvette Cedex (France)
2011-11-15
This study deals with a hybrid system consisting in quaterthiophene derivative encapsulated inside single-walled and multi-walled carbon nanotubes. Investigations of the encapsulation step are performed by transmission electron microscopy. Raman spectroscopy data point out different behaviors depending on the laser excitation energy with respect to the optical absorption of quaterthiophene. At low excitation energy (far from the oligomer resonance window) there is no significant modification of the Raman spectra before and after encapsulation. By contrast, at high excitation energy (close to the oligomer resonance window), Raman spectra exhibit a G-band shift together with an important RBM intensity loss, suggesting a significant charge transfer between the inserted molecule and the host nanotubes. Those results suggest a photo induced process leading to a significant charge transfer. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
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Directory of Open Access Journals (Sweden)
Li Yanbin
2006-03-01
Full Text Available Abstract Background Avian influenza virus H5N1 has demonstrated considerable pandemic potential. Currently, no effective vaccines for H5N1 infection are available, so passive immunotherapy may be an alternative strategy. To investigate the possible therapeutic effect of antibody against highly pathogenic H5N1 virus on a mammal host, we prepared specific equine anti-H5N1 IgGs from horses vaccinated with inactivated H5N1 virus, and then obtained the F(ab'2 fragments by pepsin digestion of IgGs. Methods The horses were vaccinated with inactivated H5N1 vaccine to prepare anti-H5N1 IgGs. The F(ab'2 fragments were purified from anti-H5N1 hyperimmune sera by a protocol for 'enhanced pepsin digestion'. The protective effect of the F(ab'2 fragments against H5N1 virus infection was determined in cultured MDCK cells by cytopathic effect (CPE assay and in a BALB/c mouse model by survival rate assay. Results By the protocol for 'enhanced pepsin digestion', total 16 g F(ab'2 fragments were finally obtained from one liter equine antisera with the purity of over 90%. The H5N1-specific F(ab'2 fragments had a HI titer of 1:1024, and the neutralization titre of F(ab'2 reached 1: 2048. The in vivo assay showed that 100 μg of the F(ab'2 fragments could protect BALB/c mice infected with a lethal dose of influenza H5N1 virus. Conclusion The availability of highly purified H5N1-specific F(ab'2 fragments may be promising for treatment of influenza H5N1 infection. Our work has provided experimental support for the application of the therapeutic equine immunoglobulin in future large primate or human trials.
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International Nuclear Information System (INIS)
Lomonosova, N.V.
1995-01-01
Using the methods of birefringence, isometrical heating, IR-dichroism and thermal optical analysis change in structure of oriented polymer-oligomer systems on the base of PS (M>10 6 ) and epoxyacrylic (EA) oligomers of aliphatic and aromatic structure is studied during the process of irradiation by fast electrons. Their mechanical properties are studied and it is established that introduction of aliphatic epoxyacrylate to PS and subsequent irradiation allow to obtain composite materials with higher values of strength, modulus of elasticity and softening temperature in isotropic and oriented states. 6 refs., 2 figs., 3 tabs
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Amyloid-beta 40 as a biomarker of cognitive impairment in acute ischemic stroke
Directory of Open Access Journals (Sweden)
Aleksey A. Kulesh
2017-01-01
Full Text Available Aim: to study the role of amyloid-beta 40 (Aβ 40 in the development of cognitive impairment in acute ischemic stroke.Materials and methods. The study included 70 patients aged 33–86 years, 46 men and 24 women. In patients with acute ischemic stroke cognitive status was assessed with Mini-Mental State Examination (MMSE, Montreal Cognitive Assessment Test (MoCA, Frontal Assessment Battery (FAB, Schulte tables, Clock Drawing Test, Test for Semantic Verbal Fluency and Five Words Test. The concentration of Aβ 40 in the cerebrospinal fluid was determined. Morphometric (size of the infarct and leukoaraiosis area, volume of the brain ventricles and hippocampus and diffusion-tensor parameters of MRI (fractional anisotropy of putamen, thalamus, hippocampus, corpus callosum, limbs of the internal capsule, the cingulate, the superior longitudinal and inferior fronto-occipital tracts were studied.Results. The concentration of Aβ 40 in the cerebrospinal fluid was 436,4 (226,0–514,0 pg/ml. The protein level was associated with the result of subtests «Orientation» (MMSE and «Attention» (MoCA, as well as indirect recall with cues in MoCA. Patients with MMSE score of 24–27 points were characterized by a lower concentration of Aβ 40 as compared to patients with a score less than 24 points. Aβ 40 concentration more than 436,4 pg/mL was associated with a more severe somatic co-morbidity of stroke (hypertension, lower hemoglobin and albumin level, higher erythrocyte sedimentation rate, a smaller volume of the brain ventricles, lower fractional anisotropy of the thalamus, cingulate tracts and contralateral hippocampus. Aβ 40 concentration more than 436,4 pg/mL was also associated with a lower global cognitive status (according to the MMSE and MoCA, as well as the reduction in certain cognitive functions, namely, attention, visual-spatial functions and memory.Conclusions. The concentration of Aβ 40 in the cerebrospinal fluid is a biological marker of
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Flame retardant cotton fabrics by electron beam-induced polymerization of vinyl phosphonate oligomer
International Nuclear Information System (INIS)
Sawai, Takeshi; Ametani, Kazuo; Enomoto, Ichiro
1988-01-01
Vinyl phosphonate oligomer is presently used commercially as a cellulosic flame retardant in conjugation with N-methylol acrylamide, using a persulfate catalyst and a thermal cure. This combination can also be cured at room temperature with electron beams, as can the vinyl phosphonate alone. For the textile application, fixation of flame retardants by electron beams with low energy is one of the most promising applications. For the purpose of preparing flame resistant cotton fabrics such as bed sheets and pajamas, flame retardant curing of vinyl phosphonate oligomer on cotton fabrics was examined using electron beams from a self-sealed electron beam processor and gamma rays from a 60 Co source. A joint investigation was undertaken by the Tokyo Metropolitan Textile Research Institute and Tokyo Metropolitan Isotope Research Center to determine the feasibility of curing vinyl phosphonate oligomer on the cotton fabrics for textile finishing. (author)
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Impact of Air Pollutants on Outpatient Visits for Acute Respiratory Outcomes
Directory of Open Access Journals (Sweden)
Ran Li
2017-01-01
Full Text Available The air pollution in China is a severe problem. The aim of our study was to investigate the impact of air pollutants on acute respiratory outcomes in outpatients. Outpatient data from 2 December 2013 to 1 December 2014 were collected, as well as air pollutant data including ozone (O3, nitrogen dioxide (NO2, carbon monoxide (CO, sulfur dioxide (SO2, and particulate matter (PM2.5 and PM10. We screened six categories of acute respiratory outcomes and analyzed their associations with different air pollutant exposures, including upper respiratory tract infection (URTI, acute bronchitis (AB, community-acquired pneumonia (CAP, acute exacerbation of chronic obstructive pulmonary disease (AECOPD, acute exacerbation of asthma (AE-asthma, and acute exacerbation of bronchiectasis (AEBX. A case-crossover design with a bidirectional control sampling approach was used for statistical analysis. A total of 57,144 patients were enrolled for analysis. PM2.5, PM10, NO2, SO2, and CO exposures were positively associated with outpatient visits for URTI, AB, CAP, and AEBX. PM10, SO2, and CO exposures were positively associated with outpatient visits for AECOPD. Exposure to O3 was positively associated with outpatient visits for AE-asthma, but negatively associated with outpatient visits for URTI, CAP, and AEBX. In conclusion, air pollutants had acute effects on outpatient visits for acute respiratory outcomes, with specific outcomes associated with specific pollutants.
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International Nuclear Information System (INIS)
Anderson, C.J.; Schwarz, S.W.; Connett, J.M.
1995-01-01
Antibody fragments labeled with a radiometal using bifunctional chelates generally undergo renal clearance followed by trapping of the metabolites, leading to high radiation doses to the kidneys. Copper-64-labeled BAT-2IT-1A3-F(ab') 2 was recently reported to accumulate in colorectal tumors in an animal model, however, kidney uptake was also high. In this study, the preparation of 64 Cu-BAT-2IT-1A3-F(ab') 2 was optimized to reduce the renal uptake. The bifunctional chelate 6-bromoacetamidobenzyl-1,4,8,11-tetraazacyclotetradecane-N,N',N double-prime,N'double-prime-tetraacetic acid (BAT) was conjugated to 1A3-F(ab') 2 using the linking agent 2-iminothiolane (2IT). The conjugation reaction produced 20% of a lower molecular weight impurity found to be TETA-1A3-Fab'. The conjugation procedure was optimized to include FPLC purification of the BAT-2IT-1A3-F(ab') 2 from TETA-1A3-Fab' after conjugation prior to labeling with 64 Cu. The biodistribution of 64 Cu-labeled FPLC-purified and unpurified conjugates was determined in normal Sprague-Dawley rats and tumor-bearing Golden Syrian hamsters. Human absorbed doses were calculated from rat biodistribution data and PET imaging of a baboon. Upon FPLC purification of the BAT-2IT-1A3-F(ab') 2 , the immunoreactivity of 64 Cu-labeled 1A3-F(ab') 2 was significantly improved over that of non-FPLC-purified 64 Cu-BAT-2IT-1A3-F(ab') 2 , and the kidney uptake was decreased in normal rats. The biodistribution in hamsters showed some improvement in both tumor uptake and kidney clearance with FPLC-purified 64 Cu-BAT-2IT-1A3-F(ab') 2 .The improved dosimetry of 64 Cu-labeled FPLC purified BAT-2IT-1A3-F(ab') 2 should more readily allow this agent to be investigated clinically to image colorectal cancer using PET. 33 refs., 7 figs., 3 tabs
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Conjugated Polymers and Oligomers: Structural and Soft Matter Aspects
DEFF Research Database (Denmark)
This book identifies modern topics and current trends of structural and soft matter aspects of conjugated polymers and oligomers. Each chapter recognizes an active research line where structural perspective dominates research and therefore the book covers fundamental aspects of persistent...
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Directory of Open Access Journals (Sweden)
Yan-Bing Xi
2017-05-01
Full Text Available Objective: To study the correlation of serum monocyte chemoattractant protein-1 (MCP-1 and vascular endothelial cadherin (VE-cadherin levels with neural function and carotid atherosclerosis in patients with acute cerebral infarction. Methods: A total of 78 patients who were diagnosed with acute cerebral infarction in our hospital between May 2013 and August 2016 were selected as pathological group, and 80 healthy volunteers who received physical examination in our hospital during the same period were selected as control group. Serum was collected to determine the levels of MCP-1, VE-cadherin, nerve injury molecules, inflammatory mediators, proteases and their hydrolysate. Results: Serum MCP-1, VE-cadherin, NGB, NSE, S100β, HMGB-1, sCD40L, YKL-40, visfatin, CatK, MMP9 and ICTP levels of pathological group were significantly higher than those of control group; serum MCP-1 and VE-cadherin levels of pathological group were positively correlated with NGB, NSE, S100β, HMGB-1, sCD40L, YKL-40, visfatin, CatK, MMP9 and ICTP levels. Conclusion: Serum MCP-1 and VE-cadherin levels abnormally increase in patients with acute cerebral infarction, and are closely related to the nerve injury and atherosclerosis process.
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Dietary flavanols and procyanidin oligomers from cocoa (Theobroma cacao) inhibit platelet function.
Murphy, Karen J; Chronopoulos, Andriana K; Singh, Indu; Francis, Maureen A; Moriarty, Helen; Pike, Marilyn J; Turner, Alan H; Mann, Neil J; Sinclair, Andrew J
2003-06-01
Flavonoids may be partly responsible for some health benefits, including antiinflammatory action and a decreased tendency for the blood to clot. An acute dose of flavanols and oligomeric procyanidins from cocoa powder inhibits platelet activation and function over 6 h in humans. This study sought to evaluate whether 28 d of supplementation with cocoa flavanols and related procyanidin oligomers would modulate human platelet reactivity and primary hemostasis and reduce oxidative markers in vivo. Thirty-two healthy subjects were assigned to consume active (234 mg cocoa flavanols and procyanidins/d) or placebo (cocoa flavanols and procyanidins/d) tablets in a blinded parallel-designed study. Platelet function was determined by measuring platelet aggregation, ATP release, and expression of activation-dependent platelet antigens by using flow cytometry. Plasma was analyzed for oxidation markers and antioxidant status. Plasma concentrations of epicatechin and catechin in the active group increased by 81% and 28%, respectively, during the intervention period. The active group had significantly lower P selectin expression and significantly lower ADP-induced aggregation and collagen-induced aggregation than did the placebo group. Plasma ascorbic acid concentrations were significantly higher in the active than in the placebo group (P antioxidant status did not change in either group. Cocoa flavanol and procyanidin supplementation for 28 d significantly increased plasma epicatechin and catechin concentrations and significantly decreased platelet function. These data support the results of acute studies that used higher doses of cocoa flavanols and procyanidins.
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Directory of Open Access Journals (Sweden)
Gajalakshmi
Full Text Available ABSTRACT Thiophene oligomer has been investigated using DFT/TDDFT calculations with an aim to check its suitability for opto electronic applications and also to analyse the influence of π-bridge. Our results revealed that thiophene oligomers have excellent π-conjugation throughout. FMO analysis give an estimate of band gap of thiophene oligomer and further revealed HOMO are localized on π - bridge, donor group and LUMO are localized on π - bridge and acceptor group. A TDDFT calculation has been performed to understand the absorption properties of them in gas phase and solvent phase. PCM calculations convey that absorption maxima show positive solvatochromism. Among the designed candidates, the one with more π - bridge show higher wavelength of absorption maxima and would be a choice for better optoelectronic materials. NBO analysis provides support for complete delocalization in these systems. It is interesting to note that oligomer with more π-bridge display an enhanced optoelectronic properties than with less π - bridge.
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DePass, L R; Maronpot, R R; Weil, C S
1985-01-01
Several important components of photocurable coatings were studied for dermal tumorigenic activity by repeated application to the skin of mice. The substances tested were 2-ethylhexyl acrylate (EHA) and methylcarbamoyloxyethyl acrylate (MCEA) (monomers); neopentyl glycol diacrylate (NPGDA), esterdiol-204-diacrylate (EDDA), and pentaerythritol tri(tetra)acrylate (PETA) (cross-linkers); and three acrylated urethane oligomers. For each bioassay, 40 C3H/HeJ male mice were dosed 3 times weekly on the dorsal skin for their lifetime with the highest dose of the test agent that caused no local irritation or reduction in body weight gain. Two negative control groups received acetone (diluent) only. A positive control group received 0.2% methylcholanthrene (MC). NPGDA and EHA had significant tumorigenic activity with tumor yields of eight and six tumor-bearing mice (three and two malignancies), respectively. The MC group had 34 mice with carcinomas and 1 additional mouse with a papilloma. MCEA had no dermal tumorigenic activity but resulted in early mortality. No skin tumors in the treatment area were observed in the other groups. Additional studies will be necessary to elucidate possible relationships between structure and tumorigenic activity for the acrylates.
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Directory of Open Access Journals (Sweden)
Nübling Georg
2012-07-01
Full Text Available Abstract Background Fibrillar amyloid-like deposits and co-deposits of tau and α-synuclein are found in several common neurodegenerative diseases. Recent evidence indicates that small oligomers are the most relevant toxic aggregate species. While tau fibril formation is well-characterized, factors influencing tau oligomerization and molecular interactions of tau and α-synuclein are not well understood. Results We used a novel approach applying confocal single-particle fluorescence to investigate the influence of tau phosphorylation and metal ions on tau oligomer formation and its coaggregation with α-synuclein at the level of individual oligomers. We show that Al3+ at physiologically relevant concentrations and tau phosphorylation by GSK-3β exert synergistic effects on the formation of a distinct SDS-resistant tau oligomer species even at nanomolar protein concentration. Moreover, tau phosphorylation and Al3+ as well as Fe3+ enhanced both formation of mixed oligomers and recruitment of α-synuclein in pre-formed tau oligomers. Conclusions Our findings provide a new perspective on interactions of tau phosphorylation, metal ions, and the formation of potentially toxic oligomer species, and elucidate molecular crosstalks between different aggregation pathways involved in neurodegeneration.
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Castruita, Griselda; Arias, Eduardo; Moggio, Ivana; Pérez, Fátima; Medellín, Diana; Torres, Román; Ziolo, Ronald; Olivas, Amelia; Giorgetti, Emilia; Muniz-Miranda, Maurizio
2009-11-01
Two series of 2,5-di(alkoxy)phenyleneethynylene oligomers were synthesized by Sonogashira-Heck coupling reaction. The chemical structure was corroborated by 1H, 13C, APT, DEPT-135 NMR, Raman, FTIR and MALDI-TOF mass spectrometry. The chemical structure of the molecules has been varied in order to study the effect on the physicochemical and optoelectronic properties of the different chain lengths of the lateral substituents (dodecanoxy and butoxy), of different terminal groups (H, Br and I), of different chain length (3, 5 and 7 repeat units in the main conjugated backbone). The thermal properties were analyzed by DSC, TGA and by temperature-dependent X-ray diffraction. The diffraction studies of the oligomers revealed a crystalline behavior for the butoxy series, while for the dodecanoxy series the X-ray patterns are consistent with a supramolecular organization formed of randomly distributed crystalline domains that exhibit a periodic structure at small angles, indicating the presence of a lamellar order. The optical properties can be modulated within a series by increasing the length of the conjugated oligomer chain. On the contrary, neither the length of the alkoxy substituents nor the terminal groups have effect on the shape of the absorption and emission spectra.
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Charge transport and dielectric relaxation processes in anilin-based oligomers
Czech Academy of Sciences Publication Activity Database
Mrlík, M.; Moučka, R.; Ilčíková, M.; Bober, Patrycja; Kazantseva, N.; Špitálský, Z.; Trchová, Miroslava; Stejskal, Jaroslav
2014-01-01
Roč. 192, June (2014), s. 37-42 ISSN 0379-6779 Institutional support: RVO:61389013 Keywords : aniline-based oligomers * conductivity * dielectric properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.252, year: 2014
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Photopolymerizable silicone monomers, oligomers, and resins
International Nuclear Information System (INIS)
Jacobine, A.F.; Nakos, S.T.
1992-01-01
The purpose of this chapter is to acquaint the general photopolymer researcher with the historical development of the chemistry and technology of photopolymerizable silicone monomers, fluids, and resins. The current status of research in these areas is assessed. The focus of this chapter is not only on the polymer chemistry and application of this technology, but also on important aspects of the synthetic chemistry involved in the preparation of UV-curable silicone monomers, oligomers, and resins. 236 refs., 6 tabs
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Theory of microphase separation in homopolymer-oligomer mixtures
Energy Technology Data Exchange (ETDEWEB)
Olemskoi, Alexander [Department of Physical Electronics, Sumy State University, Rimskii-Korsakov St. 2, 40007 Sumy (Ukraine)]. E-mail: alex@ufn.ru; Savelyev, Alexey [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290 (United States)]. E-mail: alexsav@unc.edu
2005-11-01
This work starts with the review of theoretical methods proposed, during past decades, for description of phase behavior in different polymer systems, involving variety of linear polymers (regular and polydisperse block (co)polymers, random polymers) and the polymer systems with non-covalent bonds of different strength. Microphase separation (MS) into different ordered mesophases is known to be the principal property of such systems. It is shown that most of the theoretical approaches proposed for description of the MS are based on the simple random phase approximation (RPA). It turns out, however, that mean field RPA method applied to description of the systems with non-covalent bonds does not provide the whole picture of MS. We show that the problem here arises when one treats both Flory-Huggins non-associated interactions and non-covalent bonds (hydrogen, ionic) within the unified RPA scheme, which is obviously rough for description of the latter type of interactions. Such a theory was developed in a few recent papers for the systems involving weak hydrogen bonds between homopolymer chains and the low molecular weight oligomers (surfactants). However, it leaves some experimental data unaccounted. The purpose of this review is to consider more detailed theory which is able to explain not only all the experimental data for the above systems but also to take into account the strength variation of non-bonding interactions. In particular, we consider the strong ionic interactions, weak hydrogen bonding, and the interactions of intermediate strength between polymer chain and short oligomers within our unifying theory. To develop such a description in a self-consistent way we propose to use a general field theory of stochastic systems. The mesoscopic (lamellar) structure of the periodically alternating layers of stretched homopolymer chains surrounded by perpendicularly oriented oligomeric tails is studied for the systems with both strong (ionic) and weak (hydrogen
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Theory of microphase separation in homopolymer-oligomer mixtures
International Nuclear Information System (INIS)
Olemskoi, Alexander; Savelyev, Alexey
2005-01-01
This work starts with the review of theoretical methods proposed, during past decades, for description of phase behavior in different polymer systems, involving variety of linear polymers (regular and polydisperse block (co)polymers, random polymers) and the polymer systems with non-covalent bonds of different strength. Microphase separation (MS) into different ordered mesophases is known to be the principal property of such systems. It is shown that most of the theoretical approaches proposed for description of the MS are based on the simple random phase approximation (RPA). It turns out, however, that mean field RPA method applied to description of the systems with non-covalent bonds does not provide the whole picture of MS. We show that the problem here arises when one treats both Flory-Huggins non-associated interactions and non-covalent bonds (hydrogen, ionic) within the unified RPA scheme, which is obviously rough for description of the latter type of interactions. Such a theory was developed in a few recent papers for the systems involving weak hydrogen bonds between homopolymer chains and the low molecular weight oligomers (surfactants). However, it leaves some experimental data unaccounted. The purpose of this review is to consider more detailed theory which is able to explain not only all the experimental data for the above systems but also to take into account the strength variation of non-bonding interactions. In particular, we consider the strong ionic interactions, weak hydrogen bonding, and the interactions of intermediate strength between polymer chain and short oligomers within our unifying theory. To develop such a description in a self-consistent way we propose to use a general field theory of stochastic systems. The mesoscopic (lamellar) structure of the periodically alternating layers of stretched homopolymer chains surrounded by perpendicularly oriented oligomeric tails is studied for the systems with both strong (ionic) and weak (hydrogen
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NEXAFS characterization of DNA components and molecular-orientation of surface-bound DNA oligomers
International Nuclear Information System (INIS)
Samuel, Newton T.; Lee, C.-Y.; Gamble, Lara J.; Fischer, Daniel A.; Castner, David G.
2006-01-01
Single stranded DNA oligomers (ssDNA) immobilized onto solid surfaces forms the basis for several biotechnological applications such as DNA microarrays, affinity separations, and biosensors. Surface structure of Surface-bound oligomers is expected to significantly influence their biological activity and interactions with the environment. In this study near-edge X-ray absorption fine structure spectroscopy (NEXAFS) is used to characterize the components of DNA (nucleobases, nucleotides and nucleosides) and the orientation information of surface-bound ssDNA. The K-edges of carbon, nitrogen and oxygen have spectra with features that are characteristic of the different chemical species present in the nucleobases of DNA. The effect of addition of the DNA sugar and phosphate components on the NEXAFS K-edge spectra was also investigated. The polarization-dependent nitrogen K-edge NEXAFS data show significant changes for different orientations of surface bound ssDNA. These results establish NEXAFS as a powerful technique for chemical and structural characterization of surface-bound DNA oligomers
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Tratamento químico superficial e metalização de ABS, PVC e blendas de PVC/ABS
Directory of Open Access Journals (Sweden)
Ana Paula Kurek
2015-04-01
Full Text Available Visando à substituição do ABS em peças cromadas, amostras de PVC e blendas de PVC/ABS, na razão mássica de 20/80, 40/60 e 60/40, foram submetidas ao pré-tratamento em solução sulfocrômica sob diferentes condições de concentração, tempo e temperatura e sendo em seguida cromadas. As modificações na superfície das peças após o condicionamento foram analisadas por microscopia eletrônica de varredura, microscopia de força atômica e rugosidade. A qualidade da deposição metálica foi avaliada por inspeção visual e teste de adesão. Os resultados mostraram que, aumentando a concentração de PVC nas peças necessitou-se de condições operacionais mais agressivas, tais como maiores temperaturas de banho, tempo de imersão e concentração de solução sulfocrômica para que ocorresse a adesão da camada metálica. De todas as condições testadas com a solução condicionante sulfocrômica no tratamento das peças de PVC e blendas PVC/ABS de 20/80 e 40/60, a concentração de 350 g/L de ácido crômico e 400 g/L de ácido sulfúrico, temperatura de 70°C e tempo de imersão de 15 minutos, ocasionou deposição do metal em toda a superfície das peças, as quais foram aprovadas nos testes de adesão e corrosão.
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Genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food
Directory of Open Access Journals (Sweden)
Makoto Nakai
2014-01-01
Full Text Available Here, we conducted in vitro genotoxicity tests to evaluate the genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food. Styrene oligomers were extracted with acetone and the extract was subjected to the Ames test (OECD test guideline No. 471 and the in vitro chromosomal aberration test (OECD test guideline No. 473 under good laboratory practice conditions. The concentrations of styrene dimers and trimers in the concentrated extract were 540 and 13,431 ppm, respectively. Extraction with acetone provided markedly higher concentrations of styrene oligomers compared with extraction with 50% ethanol aqueous solution, which is the food simulant currently recommended for use in safety assessments of polystyrene by both the United States Food and Drug Administration and the European Food Safety Authority. And these high concentrations of styrene dimers and trimers were utilized for the evaluation of genotoxicity in vitro. Ames tests using five bacterial tester strains were negative both in the presence or absence of metabolic activation. The in vitro chromosomal aberration test using Chinese hamster lung cells (CHL/IU was also negative. Together, these results suggest that the risk of the genotoxicity of styrene oligomers that migrate from polystyrene food packaging into food is very low.
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Zaidi, Sayyed K; Perez, Andrew W; White, Elizabeth S; Lian, Jane B; Stein, Janet L; Stein, Gary S
2017-06-20
Acute myeloid leukemia (AML) is characterized by an aggressive clinical course and frequent cytogenetic abnormalities that include specific chromosomal translocations. The 8;21 chromosomal rearrangement disrupts the key hematopoietic RUNX1 transcription factor, and contributes to leukemia through recruitment of co-repressor complexes to RUNX1 target genes, altered subnuclear localization, and deregulation of the myeloid gene regulatory program. However, a role of non-coding microRNAs (miRs) in t(8;21)-mediated leukemogenesis is minimally understood. We present evidence of an interplay between the tumor suppressor miR-29b-1 and the AML1-ETO (also designated RUNX1-RUNX1T1) oncogene that is encoded by the t(8;21). We find that AML1-ETO and corepressor NCoR co-occupy the miR-29a/b-1 locus and downregulate its expression in leukemia cells. Conversely, re-introduction of miR-29b-1 in leukemia cells expressing AML1-ETO causes significant downregulation at the protein level through direct targeting of the 3' untranslated region of the chimeric transcript. Restoration of miR-29b-1 expression in leukemia cells results in decreased cell growth and increased apoptosis. The AML1-ETO-dependent differentiation block and transcriptional program are partially reversed by miR-29b-1. Our findings establish a novel regulatory circuit between the tumor-suppressive miR-29b-1 and the oncogenic AML1-ETO that controls the leukemic phenotype in t(8;21)-carrying acute myeloid leukemia.
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Energy Technology Data Exchange (ETDEWEB)
Lamki, L M; Murray, J L; Rosenblum, M G; Patt, Y Z; Babaian, Richard; Unger, M W
1988-08-01
We have evaluated immunoscintigraphy in cancer patients using four /sup 111/In-labelled murine monoclonal antibodies (MoAb): 96.5 (anti-P97 of melanoma), ZME-018 (anti-high molecular weight antibody of melanoma), ZCE-025 (anti-CEA for colon cancer) and PAY-276 (anti-prostatic acid phosphatase for prostatic cancer). The effect of increasing the doses of unlabelled MoAb (co-infused with 1 mg labelled MoAb) on the relative body distribution of each labelled MoAb was assessed. Localization in the liver decreased significantly in all cases, with increasing MoAb dose, except for ZME-018. Localization in other organs increased significantly as the liver activity decreased. The spleen activity, however, fell in the case of MoAb ZME-018. Blood-pool activity increased with MoAb dose in all four MoAbs. These findings correlated with the rise in the detection rate of metastases, the plasma half-life, and other pharmacokinetic parameters. However, the dose level at which this correlation occurred varied with each antibody. These data demonstrate the co-infusion of unlabelled MoAb with /sup 111/In-labelled MoAb could alter the organ distribution, pharmacokinetics and tumour uptake in a favourable manner, though the degree to which this occurs depends on the antibody in question.
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DEFF Research Database (Denmark)
Yuan, Yiyang; Krogh, Paul Henning; Bai, Xue
2014-01-01
The impact of Bt proteins on non-target arthropods is less understood than their effects on target organisms where the mechanism of toxic action is known. Here, we report the effects of two Bt proteins, Cry1Ab and Cry1Ac, on gene expression in the non-target collembolan, Folsomia candida....... A customized microarray was used to study gene expression in F. candida specimens that were exposed to Cry1Ab and Cry1Ac. All selected transcripts were subsequently confirmed by qPCR. Eleven transcripts were finally verified, and three of them were annotated. The responses of all eleven transcripts were...... tested in specimens for both Cry1Ab and Cry1Ac at a series of concentrations. These transcripts were separated into two and three groups for Cry1Ab and Cry1Ac, respectively, depend on their expression levels. However, those eleven transcripts did not respond to the Bt proteins in Bt-rice residues....
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DEFF Research Database (Denmark)
Mysling, Simon; Betzer, Cristine; Jensen, Poul Henning
2013-01-01
Soluble oligomers formed by α-synuclein (αSN) are suspected to play a central role in neuronal cell death during Parkinson's disease. While studies have probed the surface structure of these oligomers, little is known about the backbone dynamics of αSN when they form soluble oligomers. Using...... analyses performed on αSN fibrils and indicated a possible zipperlike maturation mechanism for αSN aggregates. We find the protected N-terminus (residues 4-17) to be of particular interest, as this region has previously been observed to be highly dynamic for both monomeric and fibrillar αSN. This region...... has mainly been described in relation to membrane binding of αSN, and structuring may be important in relation to disease....
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Wang, Keng; Tao, Lei; Su, Jianbing; Zhang, Yueyang; Zou, Binhua; Wang, Yiyuan; Li, Xiaojuan
2016-09-01
Objective To observe the immunosuppressive function of regulatory B cells (Bregs) in vitro after activated by CpG oligodeoxynucleotide (CpG-ODN) and anti-CD40 mAb. Methods Mice splenic CD5(+)CD1d(high)B cells and CD5(-)CD1d(low)B cells were sorted by flow cytometry. These B cells were first stimulated with CpG-ODN combined with anti-CD40 mAb for 24 hours, and then co-cultured with purified CD4(+)T cells. The interleukin 10 (IL-10) expression in the activated Bregs and other B cell subset, as well as the proliferation and interferon γ (IFN-γ) expression in the CD4(+) T cells activated by anti-CD3 mAb plus anti-CD28 mAb were determined by flow cytometry. Results CD5(+)CD1d(high) B cells activated by CpG-ODN plus anti-CD40 mAb blocked the up-regulated CD4(+)T proliferation and significantly reduced the IFN-γ level. At the same time, activated CD5(-)CD1d(low)B cells showed no inhibitory effect on CD4(+)T cells. Further study revealed that IL-10 expression in the CD5(+)CD1d(high) B cells were much higher than that in the CD5(-)CD1d(low)B cells after stimulated with CpG-ODN combined with anti-CD40 mAb for 24 hours. Conclusion CD5(+)CD1d(high) B cells activated by CpG-ODN combined with anti-CD40 mAb have immune inhibitory effects on CD4(+)T cell activation in vitro , which possibly due to IL-10 secretion.
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New tool for spreading proteins to the environment: Cry1Ab toxin immobilized to bioplastics.
Moldes, Cristina; Farinós, Gema P; de Eugenio, Laura I; García, Pedro; García, José L; Ortego, Félix; Hernández-Crespo, Pedro; Castañera, Pedro; Prieto, María A
2006-08-01
A new tool to provide an environmentally friendly way to deliver active proteins to the environment has been developed, based on the use of polyhydroxyalkanoate (PHA, bioplastic) granules. To illustrate this novel approach, a derived Cry1Ab insect-specific toxin protein was in vivo immobilized into PHA granules through the polypeptide tag BioF. The new toxin, named Fk-Bt1, was shown to be active against Sesamia nonagrioides (Lepidoptera: Noctuidae). The dose-mortality responses of the new toxin granule formulation (PFk-Bt1) and purified Cry1Ab have been compared, demonstrating the effectiveness of PFk-Bt1 and suggesting a common mode of action.
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Savateev, A.; Pronkin, S.; Epping, J.; Willinger, M.; Antonietti, M.; Dontsova, D.
2017-01-01
The thermally induced topotactic transformation of organic polymeric semiconductors is achieved using similarity of the chemical structures of the two C,N,H-containing materials. Namely, the oligomer of 3-aminotriazole-1,2,4 (OATA) is transformed into an electronically modified graphitic carbon nitride (OATA-CN) upon heating at 550 °C. During the transition, the flat band potential of the organic semiconductor is only slightly shifted from -0.11 eV to -0.06 eV, while the optical band gap is s...
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Brendle, Katrina; Schwarz, Ulrike; Jäger, Patrick; Weis, Patrick; Kappes, Manfred
2016-11-03
We have combined ion mobility mass spectrometry with quantum chemical calculations to investigate the gas-phase structures of multiply negatively charged oligomers of meso-tetra(4-sulfonatophenyl)metalloporphyrins comprising the divalent metal centers Zn II , Cu II , and Pd II . Sets of candidate structures were obtained by geometry optimizations based on calculations at both the semiempirical PM7 and density functional theory (DFT) levels. The corresponding theoretical cross sections were calculated with the projection approximation and also with the trajectory method. By comparing these collision cross sections with the respective experimental values we were able to assign oligomer structures up to the tetramer. In most cases the cross sections of the lowest energy isomers predicted by theory were found to agree with the measurements to within the experimental uncertainty (2%). Specifically, we find that for a given oligomer size the structures are independent of the metal center but depend strongly on the charge state. Oligomers in low charge states with a correspondingly larger number of sodium counterions tend to form stacked, cofacial structures reminiscent of H-aggregate motifs observed in solution. By contrast, in higher charge states, the stack opens to form coplanar structures.
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Energy Technology Data Exchange (ETDEWEB)
Katayama, Sonja, E-mail: sonja.katayama@med.uni-heidelberg.de [Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld, Heidelberg (Germany); Striecker, Thorbjoern; Kessel, Kerstin [Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld, Heidelberg (Germany); Sterzing, Florian [Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld, Heidelberg (Germany); Department of Radiation Oncology, German Cancer Research Center, Im Neuenheimer Feld, Heidelberg (Germany); Habl, Gregor [Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld, Heidelberg (Germany); Edler, Lutz [Department of Biostatistics, German Cancer Research Center, Im Neuenheimer Feld, Heidelberg (Germany); Debus, Juergen [Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld, Heidelberg (Germany); Department of Radiation Oncology, German Cancer Research Center, Im Neuenheimer Feld, Heidelberg (Germany); Herfarth, Klaus [Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld, Heidelberg (Germany)
2014-11-15
Purpose: Hypofractionated radiation therapy as primary treatment for prostate cancer is currently being investigated in large phase 3 trials. However, there are few data on postoperative hypofractionation. The Radiation therapy for the Prostate Bed With or Without the Pelvic Lymph Nodes (PRIAMOS 1) trial was initiated as a prospective phase 2 trial to assess treatment safety and toxicity of a hypofractionated intensity modulated radiation therapy (IMRT) of the prostate bed. Methods and Materials: From February to September 2012, 40 patients with indications for adjuvant or salvage radiation therapy were enrolled. One patient dropped out before treatment. Patients received 54 Gy in 18 fractions to the prostate bed with IMRT and daily image guidance. Gastrointestinal (GI) and genitourinary (GU) toxicities (according to National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0) were recorded weekly during treatment and 10 weeks after radiation therapy. Results: Overall acute toxicity was favorable, with no recorded adverse events grade ≥3. Acute GI toxicity rates were 56.4% (grade 1) and 17.9% (grade 2). Acute GU toxicity was recorded in 35.9% of patients (maximum grade 1). Urinary stress incontinence was not influenced by radiation therapy. The incidence of grade 1 urinary urge incontinence increased from 2.6% before to 23.1% 10 weeks after therapy, but grade 2 urge incontinence remained unchanged. Conclusions: Postoperative hypofractionated IMRT of the prostate bed is tolerated well, with no severe acute side effects.
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Coronavirus nucleocapsid proteins assemble constitutively in high molecular oligomers
Cong, Yingying; Kriegenburg, Franziska; de Haan, Cornelis A. M.; Reggiori, Fulvio
2017-01-01
Coronaviruses (CoV) are enveloped viruses and rely on their nucleocapsid N protein to incorporate the positive-stranded genomic RNA into the virions. CoV N proteins form oligomers but the mechanism and relevance underlying their multimerization remain to be fully understood. Using in vitro pull-down
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Directory of Open Access Journals (Sweden)
Yingying Wang
2015-12-01
Full Text Available Bacillus thuringiensis (Bt Cry toxins from the Cry1A family demonstrate significantly different toxicities against members of the family Noctuidae for unknown reasons. In this study, membrane potential was measured and analyzed in freshly isolated midgut samples from Mythimna separata and Agrotis ipsilon larvae under oral administration and in vitro incubation with Bt toxin Cry1Ab to elucidate the mechanism of action for further control of these pests. Bioassay results showed that the larvae of M. separata achieved a LD50 of 258.84 ng/larva at 24 h after ingestion; M. separata larvae were at least eightfold more sensitive than A. ipsilon larvae to Cry1Ab. Force-feeding showed that the observed midgut apical-membrane potential (Vam of M. separata larvae was significantly depolarized from −82.9 ± 6.6 mV to −19.9 ± 7.2 mV at 8 h after ingestion of 1 μg activated Cry1Ab, whereas no obvious changes were detected in A. ipsilon larvae with dosage of 5 μg Cry1Ab. The activated Cry1Ab caused a distinct concentration-dependent depolarization of the apical membrane; Vam was reduced by 50% after 14.7 ± 0.2, 9.8 ± 0.4, and 7.6 ± 0.6 min of treatment with 1, 5, and 10 μg/mL Cry1Ab, respectively. Cry1Ab showed a minimal effect on A. ipsilon larvae even at 20 μg/mL, and Vam decreased by 26.3% ± 2.3% after 15 min. The concentrations of Cry1Ab displayed no significant effect on the basolateral side of the epithelium. The Vam of A. ipsilon (−33.19 ± 6.29 mV, n = 51 was only half that of M. separata (−80.94 ± 6.95 mV, n = 75. The different degrees of sensitivity to Cry1Ab were speculatively associated with various habits, as well as the diverse physiological or biochemical characteristics of the midgut cell membranes.
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International Nuclear Information System (INIS)
Porzio, William; Destri, Silvia; Giovanella, Umberto; Pasini, Mariacecilia; Marin, Luminita; Iosip, Mariana Dana; Campione, Marcello
2007-01-01
A series of three thiophene based oligomers has been extensively characterized. The chemical design has been addressed to obtain ionization potential (IP) and electronic affinity (EA) values matching the work function of commonly used electrode materials. Such IP and EA values were tested by cyclovoltammetry. In order to tune electron-donation and drawing strength the sequence of the molecule subunits in the oligomer has been varied. The thermal properties with particular reference to their stability during preparation and operation were checked by using differential scanning calorimetry, polarised light microscopy and thermogravimetric analysis techniques. Prototypes of thin film field effect transistor, based on this series of oligomers have been electrically and structurally characterized. The long axes of the molecules are oriented nearly perpendicular to the gate insulator, in agreement with both highly sensitive X-ray diffraction and atomic force microscopy. From powder diffraction data the structure of oligomer I was solved. A general relation is envisaged between charge mobility and packing closeness in the series. For the most promising molecule a study of mobility/temperature behaviour was performed yielding interesting results
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Gao, Hongfei; Wen, Luke; Wu, Yuhua; Fu, Zhifeng; Wu, Gang
2017-11-15
The development of genetically modified (GM) insect-resistant crops has aroused great public concern about the risks on the eco-environment resulting from a release of toxic Cry proteins (such as Cry1Ab) to the soil. Therefore, it is of crucial importance to measure the Cry proteins level and the GM crops content. Here, we have tested for the first time a method that uses novel carbon nanospheres (CNPs) label-free electrochemiluminescent (ECL) immunosensor for the ultrasensitive quantification of Cry1Ab and GM crops. In this work, novel CNPs were prepared from printer toner with a very facile approach, and linked with anti-Cry1Ab antibodies to modify a golden working electrode. The immunoreaction between Cry1Ab and its antibody formed an immunocomplex on the bioreceptor region of the sensor, which inhibited electron transfer between the electrode surface and the ECL substance, leading to a decrease of ECL response. Under the optimal conditions, the fabricated label-free ECL immunosensor determined Cry1Ab down to 3.0pgmL -1 within a linear range of 0.010-1.0ngmL -1 , showing significant improvement of sensitivity than that of most previous reports. Meanwhile, the proposed method was successfully applied for GM rice BT63 and GM maize MON810 detections down to 0.010% and 0.020%, respectively. Due to its outstanding advantages such as high sensitivity, ideal selectivity, simple fabrication, rapid detection, and low cost, the developed method can be considered as a powerful and pioneering tool for GM crops detection. Its use can also be extended to other toxin protein sensing in foods. Copyright © 2017. Published by Elsevier B.V.
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Directory of Open Access Journals (Sweden)
Thomas Fischöder
2017-08-01
Full Text Available Repeats of the disaccharide unit N-acetyllactosamine (LacNAc occur as type 1 (Galβ1, 3GlcNAc and type 2 (Galβ1, 4GlcNAc glycosylation motifs on glycoproteins and glycolipids. The LacNAc motif acts as binding ligand for lectins and is involved in many biological recognition events. To the best of our knowledge, we present, for the first time, the synthesis of LacNAc type 1 oligomers using recombinant β1,3-galactosyltransferase from Escherichia coli and β1,3-N-acetylglucosaminyltranferase from Helicobacter pylori. Tetrasaccharide glycans presenting LacNAc type 1 repeats or LacNAc type 1 at the reducing or non-reducing end, respectively, were conjugated to bovine serum albumin as a protein scaffold by squarate linker chemistry. The resulting multivalent LacNAc type 1 presenting neo-glycoproteins were further studied for specific binding of the tumor-associated human galectin 3 (Gal-3 and its truncated counterpart Gal-3∆ in an enzyme-linked lectin assay (ELLA. We observed a significantly increased affinity of Gal-3∆ towards the multivalent neo-glycoprotein presenting LacNAc type 1 repeating units. This is the first evidence for differences in glycan selectivity of Gal-3∆ and Gal-3 and may be further utilized for tracing Gal-3∆ during tumor progression and therapy.
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International Nuclear Information System (INIS)
Chen Yujuan; Liu Xueyuan; Bian Weihong; Du Xinlu; Yang Hongyan
2006-01-01
Objective: To investigate the dynamic changes of serum insulin-like growth factor-1 (IGF-1) levels in patients with acute cerebrovascular accident. Methods: Serum IGF-1 levels were determined with RIA in 40 patients with cerebral infarction, 20 patients with lacunar infarcts and 40 patients with cerebral haemorrhage within 3days after onset and on d14 as well as in 30 controls. Results: The serum IGF-1 levels in patients with cerebral vascular accidents were significantly lower than those in controls (P 0.05). Conclusion: Serum levels of IGF-1 dropped markedly during the acute stage after cerebrovascular accident and the magnitude might reflect the severity of the event, IGF-1 might be capable of crossing the blood-brain barrier after cerebrovascular accident and providing some protection against nerve injury, this fact might be of potential clinical applicability. (authors)
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Rapamycin-induced oligomer formation system of FRB-FKBP fusion proteins.
Inobe, Tomonao; Nukina, Nobuyuki
2016-07-01
Most proteins form larger protein complexes and perform multiple functions in the cell. Thus, artificial regulation of protein complex formation controls the cellular functions that involve protein complexes. Although several artificial dimerization systems have already been used for numerous applications in biomedical research, cellular protein complexes form not only simple dimers but also larger oligomers. In this study, we showed that fusion proteins comprising the induced heterodimer formation proteins FRB and FKBP formed various oligomers upon addition of rapamycin. By adjusting the configuration of fusion proteins, we succeeded in generating an inducible tetramer formation system. Proteins of interest also formed tetramers by fusing to the inducible tetramer formation system, which exhibits its utility in a broad range of biological applications. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
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MHD stability studies in the Proto S-1 A/B device
International Nuclear Information System (INIS)
Munson, C.; Janos, A.; Newhouse, M.; Salberta, E.; Wysocki, F.; Yamada, M.
1982-01-01
An experimental study of the gross MHD stability properties of Spheromak plasmas in the Proto S-1 A/B device is presented. Utilizing the previously demonstrated S-1 slow formation technique, plasmas have been produced which exhibit the predicted tilting instability in a regime of slightly negative field index. A relatively simple passive coil system suggested by numerical stability studies has proven to be effective in stabilizing the observed tilting mode
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DEFF Research Database (Denmark)
Shiraishi, Takehiko; Nielsen, Peter E
2012-01-01
We have explored the merits of a novel delivery strategy for the antisense oligomers based on cell penetrating peptide (CPP) conjugated to a carrier PNA with sequence complementary to part of the antisense oligomer. The effect of these carrier CPP-PNAs was evaluated by using antisense PNA targeting......-PNA (cPNA1(7)-(D-Arg)8) and hexamer carrier decanoyl-CPP-PNA (Deca-cPNA1(6)-(D-Arg)8), respectively, without showing significant additional cellular toxicity. Most interestingly, the activity reached the same level obtained by enhancement with endosomolytic chloroquine (CQ) treatment, suggesting...... that the carrier might facilitate endosomal escape. Furthermore, 50% downregulation of luciferase expression at 60 nM siRNA was obtained using this carrier CPP-PNA delivery strategy (with CQ co-treatment) for a single stranded antisense RNA targeting normal luciferase mRNA. These results indicated that CPP...
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40 CFR 40.115-1 - Construction.
2010-07-01
... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Construction. 40.115-1 Section 40.115-1... DEMONSTRATION GRANTS § 40.115-1 Construction. May include the preliminary planning to determine the economic and... action necessary to the construction of a facility, the erection, acquisition, alteration, remodeling...
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Directory of Open Access Journals (Sweden)
Manuel Salmón
2013-10-01
Full Text Available Tonsil Actisil FF, which is a commercial bentonitic clay, promotes the formation of cycloveratrylene macrocycles and benzyl oligomers from the corresponding benzyl alcohols in good yields under microwave heating and infrared irradiation in the absence of solvent in both cases. The catalytic reaction is sensitive to the type of substituent on the aromatic ring. Thus, when benzyl alcohol was substituted with a methylenedioxy, two methoxy or three methoxy groups, a cyclooligomerisation process was induced. Unsubstituted, methyl and methoxy benzyl alcohols yielded linear oligomers. In addition, computational chemistry calculations were performed to establish a validated mechanistic pathway to explain the growth of the obtained linear oligomers.
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International Nuclear Information System (INIS)
Lomonosova, N.V.
1995-01-01
The change in the structure of oriented polymer-oligomer systems based on polystyrene (PS) with M > 10 6 and epoxy acrylate oligomers (aliphatic and aromatic) under irradiation by accelerated electrons was studied using birefringence, isometric heating, IR dichroism, and thermooptical analysis. Mechanical properties of these systems were investigated. It was found that, by adding aliphatic epoxy acrylate to PS and further irradiating this mixture, one can obtain both isotropic and oriented composites with higher strengths, elasticity moduli, and glass transition temperatures
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Böttger, Rita; Schaller, Jörg; Lintow, Sven; Gert Dudel, E
2015-03-01
The increasing cultivation of genetically modified corn plants (Zea mays) during the last decades is suggested as a potential risk to the environment. One of these genetically modified variety expressed the insecticidal Cry1Ab protein originating from Bacillus thuringiensis (Bt), resulting in resistance against Ostrinia nubilalis, the European corn borer. Transgenic litter material is extensively studied regarding the decomposition in soils. However, only a few field studies analyzed the fate of the Cry1Ab protein and the impact of green and senescent leaf litter from corn on the decomposition rate and related ecosystem functions in aquatic environments. Consequently, a microbial litter decomposition experiment was conducted under controlled semi-natural conditions in batch culture using two maize varieties: one variety with Cry1Ab and another one with the appertaining Iso-line as control treatment. The results showed no significant differences between the treatment with Cry1Ab and the Iso-line regarding loss of total mass in dry weight of 43% for Iso-line and 45% for Bt-corn litter, lignin content increased to 137.5% (Iso-line) and 115.7% (Bt-corn), and phenol loss decreased by 53.6% (Iso-line), 62.2% (Bt-corn) during three weeks of the experiment. At the end of the experiment Cry1Ab protein was still detected with 6% of the initial concentration. A slightly but significant lower cellulose content was found for the Cry1Ab treatment compared to the Iso-line litter at the end of the experiment. The significant higher total protein (25%) and nitrogen (25%) content in Bt corn, most likely due to the additionally expression of the transgenic protein, may increase the microbial cellulose degradation and decrease microbial lignin degradation. In conclusion a relevant year by year input of protein and therefore nitrogen rich Bt corn litter into aquatic environments may affect the balanced nutrient turnover in aquatic ecosystems. Copyright © 2014 Elsevier Inc. All rights
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International Nuclear Information System (INIS)
Hwang, Hyun-Sik; Khang, Dahl-Young
2015-01-01
‘Smart’ (or selective) electrode for charge carriers, both electrons and holes, in organic bulk-heterojunction (BHJ) solar cells using insertion layers made of hydrophobically-recovered and contact-printed siloxane oligomers between electrodes and active material has been demonstrated. The siloxane oligomer insertion layer has been formed at a given interface simply by conformally-contacting a cured slab of polydimethylsiloxane stamp for less than 100 s. All the devices, either siloxane oligomer printed at one interface only or printed at both interfaces, showed efficiency enhancement when compared to non-printed ones. The possible mechanism that is responsible for the observed efficiency enhancement has been discussed based on the point of optimum symmetry and photocurrent analysis. Besides its simplicity and large-area applicability, the demonstrated contact-printing technique does not involve any vacuum or wet processing steps and thus can be very useful for the roll-based, continuous production scheme for organic BHJ solar cells. - Highlights: • Carrier-selective insertion layer in organic bulk heterojunction solar cells • Simple contact-printing of siloxane oligomers improves cell efficiency. • Printed siloxane layer reduces carrier recombination at electrode surfaces. • Siloxane insertion layer works equally well at both electrode surfaces. • Patterned PDMS stamp shortens the printing time within 100 s
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Bentsen, Christopher; McLaughlin, Lisa; Mitchell, Elizabeth; Ferrera, Carol; Liska, Sally; Myers, Robert; Peel, Sheila; Swenson, Paul; Gadelle, Stephane; Shriver, M Kathleen
2011-12-01
A multi-center study was conducted to evaluate the Bio-Rad GS HIV Combo Ag/Ab EIA, a 4th generation HIV-1/HIV-2 assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma in adult and pediatric populations. The objectives of the study were to assess assay performance for the detection of acute HIV infections; sensitivity in known HIV positive samples; percent agreement with HIV status; specificity in low and high risk individuals of unknown HIV status; and to compare assay performance to a 3rd generation HIV assay. The evaluation included testing 9150 samples at four U.S. clinical trial sites, using three kit lots. Unlinked samples were from routine testing, repositories or purchased from vendors. GS HIV Combo Ag/Ab EIA detection in samples from individuals in two separate populations with acute HIV infection was 95.2% (20/21) and 86.4% (38/44). Sensitivity was 100% (1603/1603) in known antibody positive [HIV-1 Groups M and O, and HIV-2] samples. HIV p24 antigen detection was 100% (53/53) in HIV-1 culture supernatants. HIV-1 seroconversion panel detection improved by a range of 0-20 days compared to a 3rd generation HIV test. Specificity was 99.9% (5989/5996) in low risk, 99.9% (959/960) in high risk and 100% (100/100) in pediatric populations. The GS HIV Combo Ag/Ab EIA significantly reduced the diagnostic window when compared to the 3rd generation screening assay, enabling earlier diagnosis of HIV infection. The performance parameters of the Bio-Rad GS HIV Combo Ag/Ab EIA are well suited for use in HIV diagnostic settings. Copyright © 2011 Elsevier B.V. All rights reserved.
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Atomistic simulation of CO 2 solubility in poly(ethylene oxide) oligomers
Hong, Bingbing; Panagiotopoulos, Athanassios Z.
2013-01-01
We have performed atomistic molecular dynamics simulations coupled with thermodynamic integration to obtain the excess chemical potential and pressure-composition phase diagrams for CO2 in poly(ethylene oxide) oligomers. Poly(ethylene oxide
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Biosorption of Acid Blue 290 (AB 290) and Acid Blue 324 (AB 324) dyes on Spirogyra rhizopus
International Nuclear Information System (INIS)
Ozer, Ayla; Akkaya, Goenuel; Turabik, Meral
2006-01-01
In this study, the biosorption of Acid Blue 290 and Acid Blue 324 on Spirogyra rhizopus, a green algae growing on fresh water, was studied with respect to initial pH, temperature, initial dye concentration and biosorbent concentration. The optimum initial pH and temperature values for AB 290 and AB 324 biosorption were found to be 2.0, 30 deg. C and 3.0, 25 deg. C, respectively. It was observed that the adsorbed AB 290 and AB 324 amounts increased with increasing the initial dye concentration up to 1500 and 750 mg/L, respectively. The Langmuir, Freundlich, Redlich-Peterson and Koble-Corrigan isotherm models were applied to the experimental equilibrium data and the isotherm constants were determined by using Polymath 4.1 software. The monolayer coverage capacities of S. rhizopus for AB 290 and AB 324 dyes were found as 1356.6 mg/g and 367.0 mg/g, respectively. The intraparticle diffusion model and the pseudo-second order kinetic model were applied to the experimental data in order to describe the removal mechanism of these acidic dyes by S. rhizopus. The pseudo-second order kinetic model described very well the biosorption kinetics of AB 290 and AB 324 dyes. Thermodynamic studies showed that the biosorption of AB 290 and AB 324 on S. rhizopus was exothermic in nature
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Directory of Open Access Journals (Sweden)
Cláudia A Zago
Full Text Available Plasmodium chabaudi infection induces a rapid and intense splenic CD4(+ T cell response that contributes to both disease pathogenesis and the control of acute parasitemia. The subsequent development of clinical immunity to disease occurs concomitantly with the persistence of low levels of chronic parasitemia. The suppressive activity of regulatory T (T(reg cells has been implicated in both development of clinical immunity and parasite persistence. To evaluate whether IL-2 is required to induce and to sustain the suppressive activity of T(reg cells in malaria, we examined in detail the effects of anti-IL-2 treatment with JES6-1 monoclonal antibody (mAb on the splenic CD4(+ T cell response during acute and chronic P. chabaudi AS infection in C57BL/6 mice. JES6-1 treatment on days 0, 2 and 4 of infection partially inhibits the expansion of the CD4(+CD25(+Foxp3(+ cell population during acute malaria. Despite the concomitant secretion of IL-2 and expression of high affinity IL-2 receptor by large CD4(+ T cells, JES6-1 treatment does not impair effector CD4(+ T cell activation and IFN-γ production. However, at the chronic phase of the disease, an enhancement of cellular and humoral responses occurs in JES6-1-treated mice, with increased production of TNF-α and parasite-specific IgG2a antibodies. Furthermore, JES6-1 mAb completely blocked the in vitro proliferation of CD4(+ T cells from non-treated chronic mice, while it further increased the response of CD4(+ T cells from JES6-1-treated chronic mice. We conclude that JES6-1 treatment impairs the expansion of T(reg cell population during early P. chabaudi malaria and enhances the Th1 cell response in the late phase of the disease.
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In vitro synthesis and purification of PhIP-deoxyguanosine and PhIP-DNA oligomer covalent complexes
Energy Technology Data Exchange (ETDEWEB)
Freeman, J.
1994-12-01
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine compound formed when meats are cooked at high temperatures. PhIP damages DNA by forming covalent complexes with DNA carcinogen. In an effort to understand how the binding of PhIP to DNA may cause cancer, it is important to characterize the structures of PhIP-damaged DNA molecules. Our HPLC data support fluorescence and {sup 32}P Post-labeling studies which indicate the formation of several species of 2{prime}deoxyguanosine-(dG) or oligodeoxynucleotide-PhIP adducts. The reaction of PhIP with dG resulted in a reddish precipitate that was likely the major adduct, N-(deoxyguanosin-8-yl)-PhIP (dG-C8-PhIP) adduct, with a more polar adduct fraction remaining in the supernatant. Reversed-phase HPLC analysis of the adducts in the supernatant revealed the existence of species of much shorter retention times than the dG-C8-PhIP adduct, confirming that these species are more polar than dG-C8-PhIP. At least four adducts were formed in the reaction of PhIP with DNA oligomer. HPLC analysis of the PhIP-DNA oligomer supernatant after butanol extractions revealed four unresolved peaks which spectra had maximum wavelengths between 340 and 360 nm. Though adduct peaks were not completely resolved, there was {approximately}3 minutes interval between the DNA oligomer peak and the adduct peaks. Furthermore, fluorescence emission data of the DNA oligomer-PhIP adduct solution show heterogeneous binding. The more polar PhIP adducts were fraction-collected and their structures will be solved by nuclear magnetic resonance or x-ray crystallography.
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Longworth, Mitchell; Banister, Samuel D.; Mack, James B. C.; Glass, Michelle; Connor, Mark; Kassiou, Michael
2016-01-01
Indazole-derived synthetic cannabinoids (SCs) featuring an alkyl substituent at the 1-position and l-valinamide at the 3-carboxamide position (e.g., AB-CHMINACA) have been identified by forensic chemists around the world, and are associated with serious adverse health effects. Regioisomerism is possible for indazole SCs, with the 2-alkyl-2H-indazole regioisomer of AB-CHMINACA recently identified in SC products in Japan. It is unknown whether this regiosiomer represents a manufacturing impurit...
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Crespo, André L B; Spencer, Terence A; Nekl, Emily; Pusztai-Carey, Marianne; Moar, William J; Siegfried, Blair D
2008-01-01
Standardization of toxin preparations derived from Bacillus thuringiensis (Berliner) used in laboratory bioassays is critical for accurately assessing possible changes in the susceptibility of field populations of target pests. Different methods were evaluated to quantify Cry1Ab, the toxin expressed by 80% of the commercially available transgenic maize that targets the European corn borer, Ostrinia nubilalis (Hübner). We compared three methods of quantification on three different toxin preparations from independent sources: enzyme-linked immunosorbent assay (ELISA), sodium dodecyl sulfate-polyacrylamide gel electrophoresis and densitometry (SDS-PAGE/densitometry), and the Bradford assay for total protein. The results were compared to those obtained by immunoblot analysis and with the results of toxin bioassays against susceptible laboratory colonies of O. nubilalis. The Bradford method resulted in statistically higher estimates than either ELISA or SDS-PAGE/densitometry but also provided the lowest coefficients of variation (CVs) for estimates of the Cry1Ab concentration (from 2.4 to 5.4%). The CV of estimates obtained by ELISA ranged from 12.8 to 26.5%, whereas the CV of estimates obtained by SDS-PAGE/densitometry ranged from 0.2 to 15.4%. We standardized toxin concentration by using SDS-PAGE/densitometry, which is the only method specific for the 65-kDa Cry1Ab protein and is not confounded by impurities detected by ELISA and Bradford assay for total protein. Bioassays with standardized Cry1Ab preparations based on SDS-PAGE/densitometry showed no significant differences in LC(50) values, although there were significant differences in growth inhibition for two of the three Cry1Ab preparations. However, the variation in larval weight caused by toxin source was only 4% of the total variation, and we conclude that standardization of Cry1Ab production and quantification by SDS-PAGE/densitometry may improve data consistency in monitoring efforts to identify changes in
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2016-01-01
The pathogenesis of Alzheimer’s disease is characterized by the aggregation and fibrillation of amyloid peptides Aβ1–40 and Aβ1–42 into amyloid plaques. Despite strong potential therapeutic interest, the structural pathways associated with the conversion of monomeric Aβ peptides into oligomeric species remain largely unknown. In particular, the higher aggregation propensity and associated toxicity of Aβ1–42 compared to that of Aβ1–40 are poorly understood. To explore in detail the structural propensity of the monomeric Aβ1–40 and Aβ1–42 peptides in solution, we recorded a large set of nuclear magnetic resonance (NMR) parameters, including chemical shifts, nuclear Overhauser effects (NOEs), and J couplings. Systematic comparisons show that at neutral pH the Aβ1–40 and Aβ1–42 peptides populate almost indistinguishable coil-like conformations. Nuclear Overhauser effect spectra collected at very high resolution remove assignment ambiguities and show no long-range NOE contacts. Six sets of backbone J couplings (3JHNHα, 3JC′C′, 3JC′Hα, 1JHαCα, 2JNCα, and 1JNCα) recorded for Aβ1–40 were used as input for the recently developed MERA Ramachandran map analysis, yielding residue-specific backbone ϕ/ψ torsion angle distributions that closely resemble random coil distributions, the absence of a significantly elevated propensity for β-conformations in the C-terminal region of the peptide, and a small but distinct propensity for αL at K28. Our results suggest that the self-association of Aβ peptides into toxic oligomers is not driven by elevated propensities of the monomeric species to adopt β-strand-like conformations. Instead, the accelerated disappearance of Aβ NMR signals in D2O over H2O, particularly pronounced for Aβ1–42, suggests that intermolecular interactions between the hydrophobic regions of the peptide dominate the aggregation process. PMID:26780756
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Swanson, Eric; Breckenridge, Leigham; McMahon, Lloyd; Som, Sreemoyee; McConnell, Ian; Bloom, George S.
2017-01-01
Aggregates composed of the microtubule associated protein, tau, are a hallmark of Alzheimer’s disease and non-Alzheimer’s tauopathies. Extracellular tau can induce the accumulation and aggregation of intracellular tau, and tau pathology can be transmitted along neural networks over time. There are six splice variants of central nervous system tau, and various oligomeric and fibrillar forms are associated with neurodegeneration in vivo. The particular extracellular forms of tau capable of transferring tau pathology from neuron to neuron remain ill defined, however, as do the consequences of intracellular tau aggregation on neuronal physiology. The present study was undertaken to compare the effects of extracellular tau monomers, oligomers, and filaments comprising various tau isoforms on the behavior of cultured neurons. We found that 2N4R or 2N3R tau oligomers provoked aggregation of endogenous intracellular tau much more effectively than monomers or fibrils, or of oligomers made from other tau isoforms, and that a mixture of all six isoforms most potently provoked intracellular tau accumulation. These effects were associated with invasion of tau into the somatodendritic compartment. Finally, we observed that 2N4R oligomers perturbed fast axonal transport of membranous organelles along microtubules. Intracellular tau accumulation was often accompanied by increases in the run length, run time and instantaneous velocity of membranous cargo. This work indicates that extracellular tau oligomers can disrupt normal neuronal homeostasis by triggering axonal tau accumulation and loss of the polarized distribution of tau, and by impairing fast axonal transport. PMID:28482642
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Karlsson, Louise; Carlsson, Björn; Hiemke, Christoph; Ahlner, Johan; Bengtsson, Finn; Schmitt, Ulrich; Kugelberg, Fredrik C
2013-11-01
According to both in vitro and in vivo data P-glycoprotein (P-gp) may restrict the uptake of several antidepressants into the brain, thus contributing to the poor success rate of current antidepressant therapies. The therapeutic activity of citalopram resides in the S-enantiomer, whereas the R-enantiomer is practically devoid of serotonin reuptake potency. To date, no in vivo data are available that address whether the enantiomers of citalopram and its metabolites are substrates of P-gp. P-gp knockout (abcb1ab (-/-)) and wild-type (abcb1ab (+/+)) mice underwent acute (single-dose) and chronic (two daily doses for 10 days) treatment with citalopram (10mg/kg) or escitalopram (5mg/kg) Serum and brain samples were collected 1-6h after the first or last i.p. injection for subsequent drug analysis by an enantioselective HPLC method. In brain, 3-fold higher concentrations of S- and R-citalopram, and its metabolites, were found in abcb1ab (-/-) mice than in abcb1ab (+/+) mice after both acute and chronic citalopram treatments. After escitalopram treatment, the S-citalopram brain concentration was 3-5 times higher in the knockout mice than in controls. The results provide novel evidence that the enantiomers of citalopram are substrates of P-gp. Possible clinical and toxicological implications of this finding need to be further elucidated. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.
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Directory of Open Access Journals (Sweden)
Yakun Zhang
2017-11-01
Full Text Available The fall webworm, Hyphantria cunea (Drury is a major invasive pest in China. Aminopeptidase N (APN isoforms in lepidopteran larvae midguts are known for their involvement in the mode of action of insecticidal crystal (Cry proteins from Bacillus thuringiensis. In the present work, we identified a putative Cry1Ab toxin-binding protein, an APN isoform designated HcAPN3, in the midgut of H. cunea by ligand blot and mass spectrometry. HcAPN3 was highly expressed throughout all larval developmental stages and was abundant in the midgut and hindgut tissues. HcAPN3 was down-regulated at 6 h, then was up-regulated significantly at 12 h and 24 h after Cry1Ab toxin treatment. We expressed HcAPN3 in insect cells and detected its interaction with Cry1Ab toxin by ligand blot assays. Furthermore, RNA interference (RNAi against HcAPN3 using oral delivery and injection of double-stranded RNA (dsRNA resulted in a 61–66% decrease in transcript level. Down-regulating of the expression of HcAPN3 was closely associated with reduced susceptibility of H. cunea to Cry1Ab. In addition, the HcAPN3E fragment peptide expressed in Escherichia coli enhanced Cry1Ab toxicity against H. cunea larvae. This work represents the first evidence to suggest that an APN in H. cunea is a putative binding protein involved in Cry1Ab susceptibility.
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Directory of Open Access Journals (Sweden)
Martin Ingelsson
2016-09-01
Full Text Available Adverse intra- and extracellular effects of toxic α-synuclein are believed to be central to the pathogenesis in Parkinson’s disease and other disorders with Lewy body pathology in the nervous system. One of the physiological roles of α-synuclein relates to the regulation of neurotransmitter release at the presynapse, although it is still unclear whether this mechanism depends on the action of monomers or smaller oligomers. As for the pathogenicity, accumulating evidence suggest that prefibrillar species, rather than the deposits per se, are responsible for the toxicity in affected cells. In particular, larger oligomers or protofibrils of α-synuclein have been shown to impair protein degradation as well as the function of several organelles, such as the mitochondria and the endoplasmic reticulum. Accumulating evidence further suggest that oligomers/protofibrils may have a toxic effect on the synapse, which may lead to disrupted electrophysiological properties. In addition, recent data indicate that oligomeric α-synuclein species can spread between cells, either as free-floating proteins or via extracellular vesicles, and thereby act as seeds to propagate disease between interconnected brain regions. Taken together, several lines of evidence suggest that α-synuclein have neurotoxic properties and therefore should be an appropriate molecular target for therapeutic intervention in Parkinson’s disease and other disorders with Lewy pathology. In this context, immunotherapy with monoclonal antibodies against α-synuclein oligomers/protofibrils should be a particularly attractive treatment option.
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Sequence-Specific Targeting of Bacterial Resistance Genes Increases Antibiotic Efficacy
Wong, Michael; Daly, Seth M.; Greenberg, David E.; Toprak, Erdal
2016-01-01
The lack of effective and well-tolerated therapies against antibiotic-resistant bacteria is a global public health problem leading to prolonged treatment and increased mortality. To improve the efficacy of existing antibiotic compounds, we introduce a new method for strategically inducing antibiotic hypersensitivity in pathogenic bacteria. Following the systematic verification that the AcrAB-TolC efflux system is one of the major determinants of the intrinsic antibiotic resistance levels in Escherichia coli, we have developed a short antisense oligomer designed to inhibit the expression of acrA and increase antibiotic susceptibility in E. coli. By employing this strategy, we can inhibit E. coli growth using 2- to 40-fold lower antibiotic doses, depending on the antibiotic compound utilized. The sensitizing effect of the antisense oligomer is highly specific to the targeted gene’s sequence, which is conserved in several bacterial genera, and the oligomer does not have any detectable toxicity against human cells. Finally, we demonstrate that antisense oligomers improve the efficacy of antibiotic combinations, allowing the combined use of even antagonistic antibiotic pairs that are typically not favored due to their reduced activities. PMID:27631336
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Targeting α-synuclein oligomers
DEFF Research Database (Denmark)
van Diggelen, Femke
Parkinson’s Disease (PD) is a complex disease, characterised by degeneration of neocortical, limbic and nigrostriatal neurons. It is unknown what initiates neurodegeneration, but soluble oligomers of the protein α-synuclein (αSn) seem to be particularly toxic, compared to insoluble fibrils...... unique characteristics, e.g. they were recognized by different conformational antibodies and DHA–αSOs also formed a second elongated species in addition to the dominant spherical species. Although further functional testing is needed, this suggests that each species has its own distinct toxic mechanism......+/K+ ATPase, V-type ATPase, VDAC, CaMKII and Rab-3A. The identification of these targets is a first step towards unravelling the toxic pathways which are activated upon synaptic binding of extracellularly added αSOs, and hopefully will contribute to the discovery of new disease modifying compounds, which can...
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Pronk, A.; Yu, F.; Vlaanderen, J.; Tielemans, E.; Preller, L.; Bobeldijk, I.; Deddens, J.A.; Latza, U.; Baur, X.; Heederik, D.
2006-01-01
Objectives: To study inhalation and dermal exposure to hexamethylene diisocyanate (HDI) and its oligomers as well as personal protection equipment (PPE) use during task performance in conjunction with urinary hexamethylene diamine (HDA) in car body repair shop workers and industrial spray painters.
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Fleuren, Emmy D. G.; Versleijen-Jonkers, Yvonne M. H.; Heskamp, Sandra; Roeffen, Melissa H. S.; Bouwman, Wilbert H.; Molkenboer-Kuenen, Janneke D. M.; van Laarhoven, Hanneke W. M.; Oyen, Wim J. G.; Boerman, Otto C.; van der Graaf, Winette T. A.
2013-01-01
To investigate whether F(ab')2-fragments of the monoclonal Insulin-like Growth Factor-1 Receptor (IGF-1R) antibody R1507 (F(ab')2-R1507) can successfully target IGF-1R in Ewing sarcomas (ES). BALB/c nude mice were subcutaneously implanted with IGF-1R-expressing human ES xenografts (EW-5 and EW-8)
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Kalberer, Markus; Sax, Mirjam; Samburova, Vera
2006-10-01
Only a minor fraction of the total organic aerosol mass can be resolved on a molecular level. High molecular weight compounds in organic aerosols have recently gained much attention because this class of compound potentially explains a major fraction of the unexplained organic aerosol mass. These compounds have been identified with different mass spectrometric methods, and compounds with molecular masses up to 1000 Da are found in secondary organic aerosols (SOA) generated from aromatic and terpene precursors in smog chamber experiments. Here, we apply matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to SOA particles from two biogenic precursors, alpha-pinene and isoprene. Similar oligomer patterns are found in these two SOA systems, but also in SOA from trimethylbenzene, an anthropogenic SOA precursor. However, different maxima molecular sizes were measured for these three SOA systems. While oligomers in alpha-pinene and isoprene have sizes mostly below 600-700 Da, they grow up to about 1000 Da in trimethylbenzene-SOA. The final molecular size of the oligomers is reached early during the particle aging process, whereas other particle properties related to aging, such as the overall acid concentration or the oligomer concentration, increase continuously over a much longer time scale. This kinetic behavior of the oligomer molecular size growth can be explained by a chain growth kinetic regime. Similar oligomer mass patterns were measured in aqueous extracts of ambient aerosol samples (measured with the same technique). Distinct differences between summer and winter were observed. In summer a few single mass peaks were measured with much higher intensity than in winter, pointing to a possible difference in the formation processes of these compounds in winter and summer.
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Directory of Open Access Journals (Sweden)
mohammad saeed sasan
2014-12-01
Full Text Available ABSTRACT Background: Acute respiratory infections (ARI are the main cause for antibiotic (AB use in all age groups specially the first two years of life. The local information about the pattern of AB prescription in ARI is a necessary part for any program which aims logical use of AB. The current study was designed to find the frequency and types of AB administration for ARI in young children (
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Segal, L; Penman, M G; Piriou, Y
2018-01-01
The potential systemic toxicity of Oligopin®, a French Maritime Pine Bark extract (FMPBE) rich in procyanidolic oligomers, was evaluated in an acute oral limit test and a 90-day repeated dose oral toxicity study with Sprague Dawley rats. The potential mutagenicity was assessed in a bacterial reverse mutation assay and in vitro mammalian chromosome aberration assay with human lymphocytes. The results indicate that Oligopin® was nongenotoxic in both bacterial and human cell assays, was not acutely toxic via oral administration at up to 2000 mg/kg and was well tolerated following 90 days of oral administration to SD rats, with a no observed adverse effect level of 1000 mg/kg/day. The lack of significant adverse systemic effects in the 90 day study is concordant with findings from several human clinical trials. The acute toxicity and mutagenicity data are consistent with data reported by AFSSA in a summary of FMPBE safety, in which a NOAEL of 100 mg/kg/day was established. In contrast, the NOAEL derived from the 90-day study with Oligopin® was 1000 mg/kg/day, suggesting that it is less systemically toxic than other FMPBE previously evaluated in subchronic studies, and comparable to proanthocyanidins extracted from grape seeds, which are widely used as nutritional supplement ingredients.
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Podocyte changes upon induction of albuminuria in Thy-1.1 transgenic mice.
Smeets, Bart; Dijkman, Henry B P M; te Loeke, Nathalie A J M; van Son, Jacco P H F; Steenbergen, Eric J; Assmann, Karel J M; Wetzels, Jack F M; Groenen, Patricia J T A
2003-12-01
Thy-1.1 transgenic mice, characterized by ectopic expression of the Thy-1.1 protein on podocytes, spontaneously develop proteinuria and focal glomerulosclerosis (FGS). Injection of a monoclonal antibody (mAb) directed against the Thy-1.1 protein in young transgenic mice induces a massive albuminuria that is followed by an accelerated FGS within 3 weeks. This albuminuria is complement and leukocyte independent. The time course of proteinuria, the pathogenesis of the acute proteinuria and the dose dependency of FGS are unknown. Albuminuria was measured in Thy-1.1 transgenic mice after injection of different doses of anti-Thy-1.1 mAb and at different time points within the first 24 h after injection. Podocytic foot processes and slit pore diameter were quantitated by electron microscopy. Changes in expression of slit pore constituents (podocin, CD2AP, nephrin and ZO-1), cytoskeleton-associated proteins (actin, alpha-actinin, ezrin and synaptopodin), the GDH-podocyte adhesion molecules alpha(3)-integrin, and heparan sulfate were studied by immunofluorescence. FGS was scored by light microscopy at 3 weeks after induction of albuminuria. Albuminuria in Thy-1.1 transgenic mice was observed within 10 min after anti-Thy-1.1 mAb injection. This rapid development of albuminuria was accompanied by a reduction in number of podocytic foot processes from 20.0 +/- 0.7/10 microm glomerular basement membrane (GBM) in saline-treated transgenic mice to 8.0 +/- 0.5 and 2.2 +/- 0.2 in anti-Thy-1.1-treated mice, at 10 min and 8 h after treatment, respectively. In addition, we observed a significant decrease in width of remaining slit pores, from 32.7 +/- 1.1 to 26.8 +/- 1.4 nm at 10 min after mAb injection. By immunofluorescence, we did not observe major changes in the expression pattern of any of the proteins studied. There was no correlation between the injected dose of the anti-Thy-1.1 mAb and the acute albuminuria. In contrast, the percentage of FGS at 3 weeks correlated with the
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NMR structure of the Arctic mutation of the Alzheimer's Aβ(1-40) peptide docked to SDS micelles
Usachev, K. S.; Filippov, A. V.; Khairutdinov, B. I.; Antzutkin, O. N.; Klochkov, V. V.
2014-11-01
The “Arctic” point mutation of the Alzheimer's amyloid β-peptide is a rare mutation leading to an early onset of Alzheimer's disease. The peptide may interact with neuronal membranes, where it can provide its toxic effects. We used 2D NMR spectroscopy to investigate the conformation of the “Arctic” mutant of Aβ1-40 Alzheimer's amyloid peptide in sodium dodecyl sulfate micelle solutions, which are the type of amphiphilic structures mimicking some properties of biomembranes. The study showed that the Arctic mutant of Aβ1-40 interacts with the surface of SDS micelles mainly through the Leu17-Asn27 310-helical region, while the Ile31-Val40 region is buried in the hydrophobic interior of the micelle. In contrast, wild-type Aβ1-40 interacts with SDS micelles through the Lys16-Asp23 α-helical region and Gly29-Met35. Both the Arctic mutant and the wild-type Aβ1-40 peptides interactions with SDS micelles are hydrophobic in nature. Aβ peptides are thought to be capable of forming pores in biomembranes that can cause changes in neuronal and endothelial cell membrane permeability. It has also been shown that Aβ peptides containing the “Arctic” mutation are more neurotoxic and aggregate more readily than the wild-type Aβ peptides at physiological conditions. Here, we propose that the extension of the helical structure of Leu17-Asn27 and a high aliphaticity (neutrality) of the C-terminal region in the Arctic Aβ peptides are consistent with the idea that formation of ion-permeable pores by Aβ oligomers may be one of prevailing mechanisms of a larger neuronal toxicity of the Arctic Aβ compared to the wild-type Aβ peptides, independent of oxidative damage and lipid peroxidation.
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SAXS and stability studies of iron-induced oligomers of bacterial frataxin CyaY.
Directory of Open Access Journals (Sweden)
Mostafa Fekry
Full Text Available Frataxin is a highly conserved protein found in both prokaryotes and eukaryotes. It is involved in several central functions in cells, which include iron delivery to biochemical processes, such as heme synthesis, assembly of iron-sulfur clusters (ISC, storage of surplus iron in conditions of iron overload, and repair of ISC in aconitase. Frataxin from different organisms has been shown to undergo iron-dependent oligomerization. At least two different classes of oligomers, with different modes of oligomer packing and stabilization, have been identified. Here, we continue our efforts to explore the factors that control the oligomerization of frataxin from different organisms, and focus on E. coli frataxin CyaY. Using small-angle X-ray scattering (SAXS, we show that higher iron-to-protein ratios lead to larger oligomeric species, and that oligomerization proceeds in a linear fashion as a results of iron oxidation. Native mass spectrometry and online size-exclusion chromatography combined with SAXS show that a dimer is the most common form of CyaY in the presence of iron at atmospheric conditions. Modeling of the dimer using the SAXS data confirms the earlier proposed head-to-tail packing arrangement of monomers. This packing mode brings several conserved acidic residues into close proximity to each other, creating an environment for metal ion binding and possibly even mineralization. Together with negative-stain electron microscopy, the experiments also show that trimers, tetramers, pentamers, and presumably higher-order oligomers may exist in solution. Nano-differential scanning fluorimetry shows that the oligomers have limited stability and may easily dissociate at elevated temperatures. The factors affecting the possible oligomerization mode are discussed.
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International Nuclear Information System (INIS)
Mehrabzadeh, M.; Honarkar, H.
2001-01-01
In this research a product of triplet blend of polyvinyl chloride, acrylonitrile-butadiene-styrene, acrylonitrile butadiene rubber (PVC/Abs/Nbr) is obtained. The physical, mechanical and thermal behaviour as well as morphology of the blend were studied. Results show that optimum properties in ratio PVC/Abs: 60/40 is obtained. For substituting the Nbr by a portion of Dop to modify the migration to surface, a triplet blend of PVC/Abs/Nbr was made. Experiments with constant amount of Nbr and variable Dop and vice versa were carried out. For preparation of triplet blend from PVC/Abs, a ratio of 60/40 was used. The best results were obtained for a blend with Nbr (10%) and PVC powder, 20% Nbr and PVC granules containing 34% Dop and the thermo formability of PVC/Abs/Nbr blend was examined as well
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International Nuclear Information System (INIS)
Du Tongxin; Wang Zizheng; Cao Jiwei; Wu Jindan; Tao Xiaojun
2009-01-01
Objective: To study the changes of serum TI, C-peptide, GAD-Ab and INS-Ab in different groups of patients with DM2 (age,course of disease and degree of obesity). Methods: Serum C-peptide(with CLIA), INS-Ab(with RIA) and TI, GAD-Ab(with ELISA) contents were measured in altogether 428 patients with DM2. Relationship between changes of the above parameters and different groups of patients was studide in accordance with age, course of disease and degree of obesity respectively. Results: 1)Relationship among different age groups:(below 50, n=86, 51-70, n=216, over 71 n=126). The serum levels of the 4 parameters were significantly higher in all age group than those in the controls(n=40). Among the various age groups, the levels of all parameters were significantly lower in age group below 50 than the levels,in the other 2 groups with the only exception of INS-Ab, which was not significantly different from that in age group 51-70.The levels were significantly different between age-group 51-70 and age groups over 70, with the only exception of GAD-Ab, which was about the same in the two age-groups. 2)Relationship between changes of serum levels and course of disease(below 5yrs n=157, 6-10yrs n=168,over 1yrs,n=103). The serum levels in patients with disease less than 5years were significantly lower than those in other groups with the exception of GAD-Ab, which was not significantly different from that in patients with disease 6-10 years. 3) Relationship among different degree of obesity(non-obese, BMI BMI≥25, n=202, super-obese BMI≥32 n=50): The serum levels of all the parameters were significantly lower in the non-obese subjects than those in the other two groups.The levels in the super-obese group were also significantly higher than those in the obese group (P<0.01, P<0.05). Conclusion: Serum levels of the 4 parameters (TI, C-peptide, GAD-Ab, INS-Ab)were significantly increased in patients with DM2, especially in the older patients with prolonged course of disease as
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40 CFR 40.135-1 - Preapplication coordination.
2010-07-01
... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Preapplication coordination. 40.135-1 Section 40.135-1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE RESEARCH AND DEMONSTRATION GRANTS § 40.135-1 Preapplication coordination. (a) All applicants. (1...
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Length dependence of rectification in organic co-oligomer spin rectifiers
International Nuclear Information System (INIS)
Hu Gui-Chao; Zhang Zhao; Li Ying; Ren Jun-Feng; Wang Chuan-Kui
2016-01-01
The rectification ratio of organic magnetic co-oligomer diodes is investigated theoretically by changing the molecular length. The results reveal two distinct length dependences of the rectification ratio: for a short molecular diode, the charge-current rectification changes little with the increase of molecular length, while the spin-current rectification is weakened sharply by the length; for a long molecular diode, both the charge-current and spin-current rectification ratios increase quickly with the length. The two kinds of dependence switch at a specific length accompanied with an inversion of the rectifying direction. The molecular ortibals and spin-resolved transmission analysis indicate that the dominant mechanism of rectification suffers a change at this specific length, that is, from asymmetric shift of molecular eigenlevels to asymmetric spatial localization of wave functions upon the reversal of bias. This work demonstrates a feasible way to control the rectification in organic co-oligomer spin diodes by adjusting the molecular length. (paper)
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Tumor delivery of antisense oligomer using trastuzumab within a streptavidin nanoparticle
Energy Technology Data Exchange (ETDEWEB)
Wang, Yi [University of Massachusetts Medical School, Division of Nuclear Medicine, Department of Radiology, Worcester, MA (United States); Yale University, Yale PET Center, Department of Diagnostic Radiology, New Haven, CT (United States); Liu, Xinrong; Chen, Ling; Cheng, Dengfeng; Rusckowski, Mary [University of Massachusetts Medical School, Division of Nuclear Medicine, Department of Radiology, Worcester, MA (United States); Hnatowich, Donald J. [University of Massachusetts Medical School, Division of Nuclear Medicine, Department of Radiology, Worcester, MA (United States); Umass Medical School, Department of Radiology, Worcester, MA (United States)
2009-12-15
Trastuzumab (Herceptin trademark) is often internalized following binding to Her2+ tumor cells. The objective of this study was to investigate whether trastuzumab can be used as a specific carrier to deliver antisense oligomers into Her2+ tumor cells both in vitro and in vivo. A biotinylated MORF oligomer antisense to RhoC mRNA and its biotinylated sense control were labeled with either lissamine for fluorescence detection or {sup 99m}Tc for radioactivity detection and were linked to biotinylated trastuzumab via streptavidin. The nanoparticles were studied in SUM190 (RhoC+, Her2+) study and SUM149 (RhoC+, Her2-) control cells in culture and as xenografts in mice. As evidence of unimpaired Her2+ binding of trastuzumab within the nanoparticle, accumulations were clearly higher in SUM190 compared to SUM149 cells and, by whole-body imaging, targeting of SUM190 tumor was similar to that expected for a radiolabeled trastuzumab. As evidence of internalization, fluorescence microscopy images of cells grown in culture and obtained from xenografts showed uniform cytoplasm distribution of the lissamine-MORF. An invasion assay showed decreased RhoC expression in SUM190 cells when incubated with the antisense MORF nanoparticles at only 100 nM. Both in cell culture and in animals, the nanoparticle with trastuzumab as specific carrier greatly improved tumor delivery of the antisense oligomer against RhoC mRNA into tumor cells overexpressing Her2 and may be of general utility. (orig.)
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Genetics Home Reference: GM2-gangliosidosis, AB variant
... Resources Genetic Testing (1 link) Genetic Testing Registry: Tay-Sachs disease, variant AB General Information from MedlinePlus (5 links) ... AB variant Activator Deficiency/GM2 Gangliosidosis Activator-deficient Tay-Sachs disease GM2 Activator Deficiency Disease GM2 gangliosidosis, type AB ...
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Co-stimulation by anti-immunoglobulin is required for B cell activation by CD40Llow T cells
DEFF Research Database (Denmark)
Poudrier, J; Owens, T
1994-01-01
cell Ag specificity by using anti-CD3/T cell receptor (TcR) monoclonal antibodies (mAb) to activate T cells. To study the role of sIg engagement in the responsiveness of B cells to T help, we pre-treated small resting B cells with soluble anti-kappa mAb prior to contact with an activated Th1 clone...... strongly. Low buoyant density B cells also responded to CD40Llow Th cells. There was no B cell response to resting Th cells. mAb against CD54/intercellular adhesion molecule-1 or major histocompatibility complex (MHC) class II completely inhibited B cell responses to CD40Llow Th1 cells, equivalent...
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Organization of the resting TCR in nanoscale oligomers.
Schamel, Wolfgang W A; Alarcón, Balbino
2013-01-01
Despite the low affinity of the T-cell antigen receptor (TCR) for its peptide/major histocompatibility complex (pMHC) ligand, T cells are very sensitive to their antigens. This paradox can be resolved if we consider that the TCR may be organized into pre-existing oligomers or nanoclusters. Such structures could improve antigen recognition by increasing the functional affinity (avidity) of the TCR-pMHC interaction and by allowing cooperativity between individual TCRs. Up to approximately 20 TCRs become tightly apposed in these nanoclusters, often in a linear manner, and such structures could reflect a relatively generalized phenomenon: the non-random concentration of membrane receptors in specific areas of the plasma membrane known as protein islands. The association of TCRs into nanoclusters can explain the enhanced kinetics of the pMHC-TCR interaction in two dimensional versus three dimensional systems, but also their existence calls for a revision of the TCR triggering models based on pMHC-induced TCR clustering. Interestingly, the B-cell receptor and the FcεRI have also been shown to form nanoclusters, suggesting that the formation of pre-existing receptor oligomers could be widely used in the immune system. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.
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Directory of Open Access Journals (Sweden)
Juozas Kulys
2005-10-01
Full Text Available Abstract: Ab initio quantum chemical calculations have been applied to the study of the molecular structure of phenol derivatives and oligomers produced during peroxidasecatalyzed oxidation. The interaction of substrates and oligomers with Arthromyces ramosus peroxidase was analyzed by docking methods. The most possible interaction site of oligomers is an active center of the peroxidase. The complexation energy increases with increasing oligomer length. However, the complexed oligomers do not form a precise (for the reaction hydrogen bonding network in the active center of the enzyme. It seems likely that strong but non productive docking of the oligomers determines peroxidase inhibition during the reaction.
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The kinetic characteristics of two Rhizopus oryzae exo-polygalacturonases acting on galacturonic acid oligomers (GalpA) were determined using isothermal titration calorimetry (ITC). RPG15 hydrolyzing (GalpA)2 demonstrated a Km of 55 uM and kcat of 10.3 s^-1^ while RPG16 was shown to have greater af...
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Plasma Endothelin-1 Levels in Preterm Neonatal Infants with Acute Respiratory Failure
Directory of Open Access Journals (Sweden)
D. V. Dmitriyev
2008-01-01
Full Text Available Increased pulmonary vascular resistance in preterm infants is associated with acute respiratory failure (ARF and at the same time endothelin-1 (E-1 plays an important role in neonatal pulmonary vascular responsiveness. Methods. Endothelin-1 levels were measured in two blood samples in 12 preterm infants with ARF and in 12 controls (at 32.2±1.3 and 29.8±1.2 weeks of gestation, respectively by enzyme immunoassay. For this, the first and second blood samples were taken at 18 to 40 hours after birth. Results. The plasma level of E-1 in the first sample did not differ between the neonates of both groups. In the second sample, significantly higher E-1 concentrations were observed in the newborns with ARF than in the controls. In the first sample, E-1 concentration were higher than in the second one in both groups (p<0.001. There was a significant positive correlation between the second E-1 sample and the SNAPPE 2 scale rating (r=0.38; p=0.02. The plasma level of E-1 in the first sample did not differ in both groups (11.9 and 12.2 pg/ml, respectively. Conclusion. Neonates with and without ARF had the similar plasma E-1 levels in the first sample, by taking into account the fact that the E-1 levels were higher in ARF than in the controls at 18 to 40 hour after birth. Increased vascular resistance in ARF may be associated with the high level of E-1. Key words: endothe-lin-1, acute respiratory failure.
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Programmable Oligomers Targeting 5′-GGGG-3′ in the Minor Groove of DNA and NF-κB Binding Inhibition
Chenoweth, David M.; Poposki, Julie A.; Marques, Michael A.; Dervan, Peter B.
2009-01-01
A series of hairpin oligomers containing benzimidazole (Bi) and imidazopyridine (Ip) rings were synthesized and screened to target 5′-WGGGGW-3′, a core sequence in the DNA binding site of NF-κB, a prolific transcription factor important in biology and disease. Five Bi and Ip containing oligomers bound to the 5′-WGGGGW-3′ site with high affinity. One of the oligomers (Im-Im-Im-Im-γ-PyBi-PyBi-β-Dp) was able to inhibit DNA binding by the transcription factor NF-κB. PMID:17095230
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Optical monitoring of spinal cord subcellular damage after acute spinal cord injury
Shadgan, Babak; Manouchehri, Neda; So, Kitty; Shortt, Katelyn; Fong, Allan; Streijger, Femke; Macnab, Andrew; Kwon, Brian K.
2018-02-01
Introduction: Sudden physical trauma to the spinal cord results in acute spinal cord injury (SCI), leading to spinal cord (SC) tissue destruction, acute inflammation, increased SC intraparenchymal pressure, and tissue ischemia, hypoxia, and cellular necrosis. The ability to monitor SC tissue viability at subcellular level, using a real-time noninvasive method, would be extremely valuable to clinicians for estimating acute SCI damage, and adjusting and monitoring treatment in the intensive care setting. This study examined the feasibility and sensitivity of a custommade near infrared spectroscopy (NIRS) sensor to monitor the oxidation state of SC mitochondrial cytochrome aa3 (CCO), which reflects the subcellular damage of SC tissue in an animal model of SCI. Methods: Six anesthetized Yorkshire pigs were studied using a custom-made multi-wavelength NIRS system with a miniaturized optical sensor applied directly on the surgically exposed SC at T9. The oxidation states of SC tissue hemoglobin and CCO were monitored before, during and after acute SCI, and during mean arterial pressure alterations. Results: Non-invasive NIRS monitoring reflected changes in SC tissue CCO, simultaneous but independent of changes in hemoglobin saturation following acute SCI. A consistent decrease in SC tissue CCO chromophore concentration (-1.98 +/- 2.1 ab, pElevation of mean arterial pressure can reduce SC tissue damage as suggested by different researchers and observed by significant increase in SC tissue CCO concentration (1.51 +/- 1.7 ab, p<0.05) in this study. Conclusions: This pilot study indicates that a novel miniaturized multi-wave NIRS sensor has the potential to monitor post-SCI changes of SC cytochrome aa3 oxygenation state in real time. Further development of this method may offer new options for improved SCI care.
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Erythema Ab igne after footbath with Chinese herbal remedies
Directory of Open Access Journals (Sweden)
Jeng-Feng Chen
2011-01-01
Full Text Available Erythema ab igne (EAI is a reticulated, telangiectatic, and hyperpigmented skin eruption resulting from chronic exposure to long-term moderate heat. The incidence has decreased substantially today because of the advent of modern central heating systems. Recently, we encountered a patient who developed EAI after 2 weeks of footbaths with Chinese herbal remedies, which she used to treat her acute ankle sprain. Alternative Chinese medicine, such as herbal footbath, is a prevalent medical practice to treat acute pains as well as many chronic musculoskeletal ailments among Chinese and Asian populations. It has also become increasingly popular in Western countries in the past decade. Herein, we would like to report an uncommon case of iatrogenic EAI caused by footbath and raise the attention of clinicians to such rare, potentially malignant-transforming, dermatosis.
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Foley, Joseph; Hill, Shannon E; Miti, Tatiana; Mulaj, Mentor; Ciesla, Marissa; Robeel, Rhonda; Persichilli, Christopher; Raynes, Rachel; Westerheide, Sandy; Muschol, Martin
2013-09-28
Deposits of fibrils formed by disease-specific proteins are the molecular hallmark of such diverse human disorders as Alzheimer's disease, type II diabetes, or rheumatoid arthritis. Amyloid fibril formation by structurally and functionally unrelated proteins exhibits many generic characteristics, most prominently the cross β-sheet structure of their mature fibrils. At the same time, amyloid formation tends to proceed along one of two separate assembly pathways yielding either stiff monomeric filaments or globular oligomers and curvilinear protofibrils. Given the focus on oligomers as major toxic species, the very existence of an oligomer-free assembly pathway is significant. Little is known, though, about the structure of the various intermediates emerging along different pathways and whether the pathways converge towards a common or distinct fibril structures. Using infrared spectroscopy we probed the structural evolution of intermediates and late-stage fibrils formed during in vitro lysozyme amyloid assembly along an oligomeric and oligomer-free pathway. Infrared spectroscopy confirmed that both pathways produced amyloid-specific β-sheet peaks, but at pathway-specific wavenumbers. We further found that the amyloid-specific dye thioflavin T responded to all intermediates along either pathway. The relative amplitudes of thioflavin T fluorescence responses displayed pathway-specific differences and could be utilized for monitoring the structural evolution of intermediates. Pathway-specific structural features obtained from infrared spectroscopy and Thioflavin T responses were identical for fibrils grown at highly acidic or at physiological pH values and showed no discernible effects of protein hydrolysis. Our results suggest that late-stage fibrils formed along either pathway are amyloidogenic in nature, but have distinguishable structural fingerprints. These pathway-specific fingerprints emerge during the earliest aggregation events and persist throughout the
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Foley, Joseph; Hill, Shannon E.; Miti, Tatiana; Mulaj, Mentor; Ciesla, Marissa; Robeel, Rhonda; Persichilli, Christopher; Raynes, Rachel; Westerheide, Sandy; Muschol, Martin
2013-09-01
Deposits of fibrils formed by disease-specific proteins are the molecular hallmark of such diverse human disorders as Alzheimer's disease, type II diabetes, or rheumatoid arthritis. Amyloid fibril formation by structurally and functionally unrelated proteins exhibits many generic characteristics, most prominently the cross β-sheet structure of their mature fibrils. At the same time, amyloid formation tends to proceed along one of two separate assembly pathways yielding either stiff monomeric filaments or globular oligomers and curvilinear protofibrils. Given the focus on oligomers as major toxic species, the very existence of an oligomer-free assembly pathway is significant. Little is known, though, about the structure of the various intermediates emerging along different pathways and whether the pathways converge towards a common or distinct fibril structures. Using infrared spectroscopy we probed the structural evolution of intermediates and late-stage fibrils formed during in vitro lysozyme amyloid assembly along an oligomeric and oligomer-free pathway. Infrared spectroscopy confirmed that both pathways produced amyloid-specific β-sheet peaks, but at pathway-specific wavenumbers. We further found that the amyloid-specific dye thioflavin T responded to all intermediates along either pathway. The relative amplitudes of thioflavin T fluorescence responses displayed pathway-specific differences and could be utilized for monitoring the structural evolution of intermediates. Pathway-specific structural features obtained from infrared spectroscopy and Thioflavin T responses were identical for fibrils grown at highly acidic or at physiological pH values and showed no discernible effects of protein hydrolysis. Our results suggest that late-stage fibrils formed along either pathway are amyloidogenic in nature, but have distinguishable structural fingerprints. These pathway-specific fingerprints emerge during the earliest aggregation events and persist throughout the
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Brela, Mateusz Z.; Boczar, Marek; Malec, Leszek M.; Wójcik, Marek J.; Nakajima, Takahito
2018-05-01
Hydrogen bond networks in uracil, 1-methyluracil and 1-methyl-4-thiouracil were studied by ab initio molecular dynamics as well as analysis of the orbital interactions. The power spectra calculated by ab initio molecular dynamics for atoms involved in hydrogen bonds were analyzed. We calculated spectra by using anharmonic approximation based on the autocorrelation function of the atom positions obtained from the Born-Oppenheimer simulations. Our results show the differences between hydrogen bond networks in uracil and its methylated derivatives. The studied methylated derivatives, 1-methyluracil as well as 1-methyl-4-thiouracil, form dimeric structures in the crystal phase, while uracil does not form that kind of structures. The presence of sulfur atom instead oxygen atom reflects weakness of the hydrogen bonds that build dimers.
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Gao, Wentong; Bie, Mengyao; Liu, Fu; Chang, Pengshan; Quan, Yiwu
2017-05-10
Polysulfide sealants have been commercially applied in many industrial fields. In this article, we study the self-healing property of the epoxy resin-cured polysulfide sealants for the first time. The obtained sealants showed a flexible range of ultimate elongation of 157-478% and a tensile strength of 1.02-0.75 MPa corresponding to different polysulfide oligomers. By taking advantage of the dynamic reversible exchange of disulfide bonds, polysulfide sealants exhibited good self-healing ability under a moderate thermal stimulus. A higher molecular weight and a lower degree of cross-linking of polysulfide oligomer were helpful in improving the ultimate elongation and healing efficiency of the polysulfide sealants. After subjecting to a temperature of 75 °C for 60 min, both the tensile strength and ultimate elongation of a fully cut sample, LP55-F, were restored to 91% of the original values, without affecting the sealing property. Furthermore, the sample exhibited excellent reshaping and reprocessing abilities. These outcomes offer a paradigm toward sustainable industrial applications of the polysulfide-based sealants.
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"Nail" and "comb" effects of cholesterol modified NIPAm oligomers on cancer targeting liposomes
Li, Wengang; Deng, Lin; Moosa, Basem; Wang, Guangchao; Mashat, Afnan; Khashab, Niveen M.
2014-01-01
Thermosensitive liposomes are a promising approach to controlled release and reduced drug cytotoxicity. Low molecular weight N-isopropylacrylamide (NIPAm) oligomers (NOs) with different architectures (main chain NOs (MCNOs) and side chain NOs (SCNOs)) were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization and radical polymerization and then separately used to prepare thermosensitive liposomes. A more controlled and enhanced release was observed for both NO liposomes compared to pristine ones. Two release mechanisms depending on the oligomer architecture, namely "nail" for MCNOs and "comb" for SCNOs, are proposed. In addition to thermosensitivity, the cancer targeting property of NO liposomes was achieved by further biotinylation of the delivery system. © The Royal Society of Chemistry.
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Eslami, Hossein; Müller-Plathe, Florian
2010-01-14
Our new simulation scheme in isosurface-isothermal-isobaric ensemble [Eslami, H.; Mozaffari, F.; Moghadasi, J.; Müller-Plathe, F. J. Chem. Phys. 2008, 129, 194702], developed to simulate confined fluids in equilibrium with bulk, is applied to simulate polyamide-6,6 oligomers confined between graphite surfaces. The reverse nonequilibrium molecular dynamics simulation technique is employed to shear the graphite surfaces. In this work, six confined systems, with different surface separations, as well as the bulk fluid are simulated. Our results show a viscosity increase with respect to the bulk fluid, with decreasing distance between surfaces. Also, the calculated viscosities of the confined systems show an oscillatory behavior with maxima corresponding to well-formed layers between the surfaces. We observe a substantial slip at the surfaces, with the slip length depending on the shear rate and on the slit width. The slip length and the slip velocity show oscillatory behavior with out-of-phase oscillations with respect to the solvation force oscillations. Moreover, the temperature difference between coldest and hottest parts of the simulation box depends on the shear rate and on the layering effect (solvation force oscillations). An analysis of oligomer deformation under flow shows preferential alignment of oligomers parallel to the surfaces with increasing shear rate.
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Comparison of Directigen Flu A+B with Real Time PCR in the Diagnosis of Influenza.
Bosevska, Golubinka; Panovski, Nikola; Janceska, Elizabeta; Mikik, Vladimir; Topuzovska, Irena Kondova; Milenkovik, Zvonko
2015-01-01
Early diagnosis and treatment of patients with influenza is the reason why physicians need rapid high-sensitivity influenza diagnostic tests that require no complex lab equipment and can be performed and interpreted within 15 min. The Aim of this study was to compare the rapid Directigen Flu A+B test with real time PCR for detection of influenza viruses in the Republic of Macedonia. One-hundred-eight respiratory samples (combined nose and throat swabs) were routinely collected for detection of influenza virus during influenza seasons. Forty-one patients were pediatric cases and 59 were adult. Their mean age was 23 years. The patients were allocated into 6 age groups: 0-4 yrs, 5-9 yrs, 10-14 yrs, 15-19 yrs, 20-64 yrs and > 65 yrs. Each sample was tested with Directigen Flu A+B and CDC real time PCR kit for detection and typisation/subtypisation of influenza according to the lab diagnostic protocol. Directigen Flu A+B identified influenza A virus in 20 (18.5%) samples and influenza B virus in two 2 (1.9%) samples. The high specificity (100%) and PPV of Directigen Flu A+B we found in our study shows that the positive results do not need to be confirmed. The overall sensitivity of Directigen Flu A+B is 35.1% for influenza A virus and 33.0% for influenza B virus. The sensitivity for influenza A is higher among children hospitalized (45.0%) and outpatients (40.0%) versus adults. Directigen Flu A+B has relatively low sensitivity for detection of influenza viruses in combined nose and throat swabs. Negative results must be confirmed.
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Directory of Open Access Journals (Sweden)
Helena Elding Larsson
Full Text Available The humoral Idiotypic Network consisting of antibodies and their anti-idiotypic antibodies (anti-Id can be temporarily upset by antigen exposure. In the healthy immune response the original equilibrium is eventually restored through counter-regulatory mechanisms. In certain autoimmune diseases however, autoantibody levels exceed those of their respective anti-Id, indicating a permanent disturbance in the respective humoral Idiotypic Network. We investigated anti-Id directed to a major Type 1 diabetes (T1D-associated autoantibody (GAD65Ab in two independent cohorts during progression to disease. Samples taken from participants of the Natural History Study showed significantly lower anti-Id levels in individuals that later progressed to T1D compared to non-progressors (anti-Id antibody index of 0.06 vs. 0.08, respectively, p = 0.02. We also observed a significant inverse correlation between anti-Id levels and age at sampling, but only in progressors (p = 0.014. Finally, anti-Id levels in progressors showed a significant decline during progression as compared to longitudinal anti-Id levels in non-progressors (median rate of change: -0.0004 vs. +0.0004, respectively, p = 0.003, suggesting a loss of anti-Id during progression. Our analysis of the Diabetes Prediction in Skåne cohort showed that early in life (age 2 individuals at risk have anti-Id levels indistinguishable from those in healthy controls, indicating that low anti-Id levels are not an innate characteristic of the immune response in individuals at risk. Notably, anti-Id levels declined significantly in individuals that later developed GAD65Ab suggesting that the decline in anti-Id levels precedes the emergence of GAD65Ab (median rate of change: -0.005 compared to matched controls (median rate of change: +0.001 (p = 0.0016. We conclude that while anti-Id are present early in life, their levels decrease prior to the appearance of GAD65Ab and to the development of T1D.
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Tanaka, Shiho; Miyamoto, Kazuhisa; Noda, Hiroaki; Endo, Haruka; Kikuta, Shingo; Sato, Ryoichi
2016-04-01
In a previous report, seven Cry1Ab-resistant strains were identified in the silkworm, Bombyx mori; these strains were shown to have a tyrosine insertion at position 234 in extracellular loop 2 of the ABC transporter C2 (BmABCC2). This insertion was confirmed to destroy the receptor function of BmABCC2 and confer the strains resistance against Cry1Ab and Cry1Ac. However, these strains were susceptible to Cry1Aa. In this report, we examined the mechanisms of the loss of receptor function of the transporter by expressing mutations in Sf9 cells. After replacement of one or two of the five amino acid residues in loop 2 of the susceptible BmABCC2 gene [BmABCC2_S] with alanine, cells still showed susceptibility, retaining the receptor function. Five mutants with single amino acid insertions at position 234 in BmABCC2 were also generated, resulting in loop 2 having six amino acids, which corresponds to replacing the tyrosine insertion in the resistant BmABCC2 gene [BmABCC2_R(+(234)Y)] with another amino acid. All five mutants exhibited loss of function against Cry1Ab and Cry1Ac. These results suggest that the amino acid sequence in loop 2 is less important than the loop size (five vs. six amino acids) or loop structure for Cry1Ab and Cry1Ac activity. Several domain-swapped mutant toxins were then generated among Cry1Aa, Cry1Ab, and Cry1Ac, which are composed of three domains. Swapped mutants containing domain II of Cry1Ab or Cry1Ac did not kill Sf9 cells expressing BmABCC2_R(+(234)Y), suggesting that domain II of the Cry toxin is related to the interaction with the receptor function of BmABCC2. This also suggests that different reactions against Bt-toxins in some B. mori strains, that is, Cry1Ab resistance or Cry1Aa susceptibility, are attributable to structural differences in domain II of Cry1A toxins. Copyright © 2016. Published by Elsevier Inc.
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Calabrese, Matthew F; Miranker, Andrew D
2007-03-16
Beta-2 Microglobulin (beta2m) is a small, globular protein, with high solubility under conditions comparable to human serum. A complication of hemodialysis in renal failure patients is the deposition of unmodified beta2m as amyloid fibers. In vitro, exposure of beta2m to equimolar Cu(2+) under near-physiological conditions can result in self-association leading to amyloid fiber formation. Previously, we have shown that the early steps in this process involve a catalyzed structural rearrangement followed by formation of discrete oligomers. These oligomers, however, have a continued requirement for Cu(2+) while mature fibers are resistant to addition of metal chelate. Here, we report that the transition from Cu(2+) dependent to chelate resistant states occurs in the context of small oligomers, dimeric to hexameric in size. These species require Cu(2+) to form, but once generated, do not need metal cation for stability. Importantly, this transition occurs gradually over several days and the resulting oligomers are isolatable and kinetically stable on timescales exceeding weeks. In addition, formation is enhanced by levels of urea similar to those found in hemodialysis patients. Our results are consistent with our hypothesis that transient encounter of full-length wild-type beta2m with transition metal cation at the dialysis membrane interface is causal to dialysis related amyloidosis.
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International Nuclear Information System (INIS)
Chen, Linxi; Campo, Pablo; Kupferle, Margaret J.
2015-01-01
Graphical abstract: - Highlights: • By-products from anodic oxidation of phenol in the presence of chloride are investigated. • Chlorinated oligomer formation is demonstrated by LC-QTOF-MS. • They have structures similar to triclosan and polychlorinated dibenzo-p-dioxins. - Abstract: Chlorinated oligomer intermediates formed during the anodic electrochemical oxidation of phenol with a boron-doped diamond electrode were studied at two different concentrations of chloride (5 mM and 50 mM). Under the same ionic strength, with sodium sulfate being the make-up ion, a 10-fold increase in Cl − led to removal rates 10.8, 1.5, and 1.4 times higher for phenol, TOC, and COD, respectively. Mono-, di- and trichlorophenols resulting from electrophilic substitution were the identified by-products. Nevertheless, discrepancies between theoretical and measured TOC values along with gaps in the mass balance of chlorine-containing species indicated the formation of unaccounted-for chlorinated by-products. Accurate mass measurements by liquid chromatography quadrupole time-of-flight mass spectrometry and MS-MS fragmentation spectra showed that additional compounds formed were dimers and trimers of phenol with structures similar to triclosan and polychlorinated dibenzo-p-dioxins
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Energy Technology Data Exchange (ETDEWEB)
Chen, Linxi; Campo, Pablo; Kupferle, Margaret J., E-mail: margaret.kupferle@uc.edu
2015-02-11
Graphical abstract: - Highlights: • By-products from anodic oxidation of phenol in the presence of chloride are investigated. • Chlorinated oligomer formation is demonstrated by LC-QTOF-MS. • They have structures similar to triclosan and polychlorinated dibenzo-p-dioxins. - Abstract: Chlorinated oligomer intermediates formed during the anodic electrochemical oxidation of phenol with a boron-doped diamond electrode were studied at two different concentrations of chloride (5 mM and 50 mM). Under the same ionic strength, with sodium sulfate being the make-up ion, a 10-fold increase in Cl{sup −} led to removal rates 10.8, 1.5, and 1.4 times higher for phenol, TOC, and COD, respectively. Mono-, di- and trichlorophenols resulting from electrophilic substitution were the identified by-products. Nevertheless, discrepancies between theoretical and measured TOC values along with gaps in the mass balance of chlorine-containing species indicated the formation of unaccounted-for chlorinated by-products. Accurate mass measurements by liquid chromatography quadrupole time-of-flight mass spectrometry and MS-MS fragmentation spectra showed that additional compounds formed were dimers and trimers of phenol with structures similar to triclosan and polychlorinated dibenzo-p-dioxins.
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International Nuclear Information System (INIS)
Klisch, Joachim; Clajus, Christin; Sychra, Vojtech; Eger, Cornelia; Strasilla, Christoph; Rosahl, Steffen; Gerlach, Ruediger; Baer, Ingrid; Hoch, Heinrich; Herbon, Uta; Borota, Ljubisa; Jonasson, Per; Liebig, Thomas
2010-01-01
The purpose of the study is to evaluate patients with wide-necked or complex aneurysms of the anterior circulation who underwent Solitaire trademark AB Neurovascular Remodeling Device-assisted coil embolization. From February 2008 to March 2009, consecutive data were collected from 45 patients with anterior circulation aneurysms. Eighteen of the patients presented with acute subarachnoid hemorrhage. Forty-six aneurysms were treated with the aid of different applications (n=49) of the Solitaire trademark AB Remodeling Device followed by standard coiling procedure (n = 43) using bioactive coils or/and bare coils. Successful positioning of the remodeling device was obtained in 95.9% of the cases. There were two thromboembolic complications (4.1%) and one severe vasospasm requiring retrieval of the device. Permanent procedural morbidity was observed in one patient (2%). The proportion of patients in whom Raymond class 1 occlusion was obtained was 53.5% (n=23). Raymond class 2 occlusion was achieved in 42% (n=18) and Raymond class 3 occlusion in 4.7% (n=2). Thirty-nine patients left the hospital with a good clinical status. The initial technical and clinical results of Solitaire trademark AB device-assisted coiling of aneurysms in the anterior circulation are highly encouraging. This technique may enhance the possibilities of the endovascular treatment of these aneurysms in clinical routine. (orig.)
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Directory of Open Access Journals (Sweden)
Cameron Martin
Full Text Available Lack of safe and effective adjuvants is a major hindrance to the development of efficacious vaccines. Signaling via CD40 pathway leads to enhanced antigen processing and presentation, nitric oxide expression, pro-inflammatory cytokine expression by antigen presenting cells, and stimulation of B-cells to undergo somatic hypermutation, immunoglobulin class switching, and proliferation. Agonistic anti-CD40 antibodies have shown promising adjuvant qualities in human and mouse vaccine studies. An anti-CD40 monoclonal antibody (mAb, designated 2E4E4, was identified and shown to have strong agonistic effects on primary cells from multiple livestock species. The mAb recognize swine, bovine, caprine, and ovine CD40, and evoked 25-fold or greater proliferation of peripheral blood mononuclear cells (PBMCs from these species relative to cells incubated with an isotype control (p<0.001. In addition, the mAb induced significant nitric oxide (p<0.0001 release by bovine macrophages. Furthermore, the mAb upregulated the expression of MHC-II by PBMCs, and stimulated significant (p<0.0001 IL-1α, IL6, IL-8, and TNF-α expression by PBMCs. These results suggest that the mAb 2E4E4 can target and stimulate cells from multiple livestock species and thus, it is a potential candidate for adjuvant development. This is the first study to report an anti-swine CD40 agonistic mAb that is also broadly reactive against multiple species.
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Mass Spectrometric Characterization of Oligomers in Pseudomonas aeruginosa Azurin Solutions
Czech Academy of Sciences Publication Activity Database
Sokolová, L.; Williamson, H.; Sýkora, Jan; Hof, Martin; Gray, H. B.; Brutschy, B.; Vlček, Antonín
2011-01-01
Roč. 115, č. 16 (2011), s. 4790-4800 ISSN 1520-6106 R&D Projects: GA MŠk(CZ) ME10124; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z40400503 Keywords : mass spectrometry * oligomers * pseudomonas aeruginosa azurin solutions Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.696, year: 2011
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International Nuclear Information System (INIS)
Kawaguchi, Yoshizo; Sasaki, Fumio; Mochizuki, Hiroyuki; Ishitsuka, Tomoaki; Tomie, Toshihisa; Ootsuka, Teruhisa; Watanabe, Shuji; Shimoi, Yukihiro; Yamao, Takeshi; Hotta, Shu
2013-01-01
We have investigated electronic states in the valence electron bands for the thin films of three thiophene/phenylene co-oligomer (TPCO) compounds, 2,5-bis(4-biphenylyl)thiophene (BP1T), 1,4-bis(5-phenylthiophen-2-yl)benzene (AC5), and 1,4-bis{5-[4-(trifluoromethyl)phenyl]thiophen-2-yl}benzene (AC5-CF 3 ), by using extreme-UV excited photoelectron spectroscopy (EUPS). By comparing both EUPS spectra and secondary electron spectra between AC5 and AC5-CF 3 , we confirm that CF 3 substitution to AC5 deepens valence states by 2 eV, and increases the ionization energy by 3 eV. From the cut-off positions of secondary electron spectra, the work functions of AC5, AC5-CF 3 , and BP1T are evaluated to be 3.8 eV, 4.8 eV, and 4.0 eV, respectively. We calculate molecular orbital (MO) energy levels by the density functional theory and compare results of calculations with those of experiments. Densities of states obtained by broadening MO levels well explain the overall features of experimental EUPS spectra of three TPCOs.
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[Wastewater from the condensation and drying section of ABS was pretreated by microelectrolysis].
Lai, Bo; Qin, Hong-Ke; Zhou, Yue-Xi; Song, Yu-Dong; Cheng, Jia-Yun; Sun, Li-Dong
2011-04-01
Wastewater from the condensation and drying section of acrylonitrile-butadiene-styrene (ABS) resin plant was pretreated by the microelectrolysis, and the effect of the influent pH value on the pollution removal efficiency of the microelectrolysis was mainly studied. In order to study the electrochemical action of the microelectrolysis for the degradation of toxic refractory organic pollutants, two control experiments of activated carbon and iron were set up. The results showed that the TOC removal efficiencies were all fluctuated between 40% and 60% under the condition of different influent pH values. The microelectrolysis can decompose and transform the toxic refractory organic pollutants and increase the BOD5/COD ratio from 0.32 to 0.60, which increased the biodegradability of ABS resin wastewater significantly. When the pH value of influent was 4.0, the BOD5/COD ratio of effluent reached 0.71. The result of UV-vis spectra indicates that the removal efficiency of the organic nitrile was the highest with influent pH was 4.0. Therefore, the best influent pH value of microelectrolysis was 4.0.
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Lu, Zengbin; Dang, Cong; Han, Naishun; Shen, Zhicheng; Peng, Yufa; Stanley, David; Ye, Gongyin
2016-04-01
The ecological risks to nontarget organisms should be rigorously assessed before Bt crops are released. Here, the impacts of a new Cry1Ab/Vip3H rice line on arthropod communities in rice agroecosystems were evaluated across 3 yr. Arthropods collected via vacuum were sorted into five guilds. The abundance and proportion of each guild as well as community-level parameters were determined in Cry1Ab/Vip3H and control rice fields. Changes in arthropod species assemblage over sampling dates were investigated by principal response curves (PRCs). Cry1Ab/Vip3H rice did not exert significant impacts on the seasonal density and proportion of each guild, except parasitoids. Detritivore seasonal density, but not its relative abundance, was significantly affected by Cry1Ab/Vip3H rice. Four community indices (species richness S, Shannon-Wiener index H', Simpson index D, and evenness index J') were similar between rice types. PRCs revealed a slight community difference between rice types in the past two tested years, with rice types accounting for 1.0-3.5% of the variance among arthropod communities. However, sampling dates explain 32.1-67.6% for these community differences. Of the 46 taxa with higher species weights, 26.1% of the taxa were significantly different, including seven taxa with higher abundance and five with lower density in Cry1Ab/Vip3H rice fields. These differences may be attributed to change in abundance of prey or hosts but not to direct effects of Bt proteins. We infer that this new Cry1Ab/Vip3H rice line poses no unintended ecological risks to the arthropod community. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Ménez, Cécile; Sutra, Jean-François; Prichard, Roger; Lespine, Anne
2012-01-01
The anthelmintics ivermectin (IVM) and moxidectin (MOX) display differences in toxicity in several host species. Entrance into the brain is restricted by the P-glycoprotein (P-gp) efflux transporter, while toxicity is mediated through the brain GABA(A) receptors. This study compared the toxicity of IVM and MOX in vivo and their interaction with GABA(A) receptors in vitro. Drug toxicity was assessed in Mdr1ab(−/−) mice P-gp-deficient after subcutaneous administration of increasing doses (0.11–2.0 and 0.23–12.9 µmol/kg for IVM and MOX in P-gp-deficient mice and half lethal doses (LD50) in wild-type mice). Survival was evaluated over 14-days. In Mdr1ab(−/−) mice, LD50 was 0.46 and 2.3 µmol/kg for IVM and MOX, respectively, demonstrating that MOX was less toxic than IVM. In P-gp-deficient mice, MOX had a lower brain-to-plasma concentration ratio and entered into the brain more slowly than IVM. The brain sublethal drug concentrations determined after administration of doses close to LD50 were, in Mdr1ab(−/−) and wild-type mice, respectively, 270 and 210 pmol/g for IVM and 830 and 740–1380 pmol/g for MOX, indicating that higher brain concentrations are required for MOX toxicity than IVM. In rat α1β2γ2 GABA channels expressed in Xenopus oocytes, IVM and MOX were both allosteric activators of the GABA-induced response. The Hill coefficient was 1.52±0.45 for IVM and 0.34±0.56 for MOX (p<0.001), while the maximum potentiation caused by IVM and MOX relative to GABA alone was 413.7±66.1 and 257.4±40.6%, respectively (p<0.05), showing that IVM causes a greater potentiation of GABA action on this receptor. Differences in the accumulation of IVM and MOX in the brain and in the interaction of IVM and MOX with GABA(A) receptors account for differences in neurotoxicity seen in intact and Mdr1-deficient animals. These differences in neurotoxicity of IVM and MOX are important in considering their use in humans. PMID:23133688
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Resonant stimulation of Raman scattering from single-crystal thiophene/phenylene co-oligomers
International Nuclear Information System (INIS)
Yanagi, Hisao; Marutani, Yusuke; Matsuoka, Naoki; Hiramatsu, Toru; Ishizumi, Atsushi; Sasaki, Fumio; Hotta, Shu
2013-01-01
Amplified Raman scattering was observed from single crystals of thiophene/phenylene co-oligomers (TPCOs). Under ns-pulsed excitation, the TPCO crystals exhibited amplified spontaneous emission (ASE) at resonant absorption wavelengths. With increasing excitation wavelength to the 0-0 absorption edge, the stimulated resonant Raman peaks appeared both in the 0-1 and 0-2 ASE band regions. When the excitation wavelength coincided with the 0-1 ASE band energy, the Raman peaks selectively appeared in the 0-2 ASE band. Such unusual enhancement of the 0-2 Raman scattering was ascribed to resonant stimulation via vibronic coupling with electronic transitions in the uniaxially oriented TPCO molecules
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Scullion, Sarah; Brown, Jon T.; Randall, Andrew D.
2015-01-01
ABSTRACT Accumulation of beta‐amyloid (Aβ) peptides in the human brain is a canonical pathological hallmark of Alzheimer's disease (AD). Recent work in Aβ‐overexpressing transgenic mice indicates that increased brain Aβ levels can be associated with aberrant epileptiform activity. In line with this, such mice can also exhibit altered intrinsic excitability (IE) of cortical and hippocampal neurons: these observations may relate to the increased prevalence of seizures in AD patients. In this study, we examined what changes in IE are produced in hippocampal CA1 pyramidal cells after 2–5 h treatment with an oligomeric preparation of synthetic human Aβ 1–42 peptide. Whole cell current clamp recordings were compared between Aβ‐(500 nM) and vehicle‐(DMSO 0.05%) treated hippocampal slices obtained from mice. The soluble Aβ treatment did not produce alterations in sub‐threshold intrinsic properties, including membrane potential, input resistance, and hyperpolarization activated “sag”. Similarly, no changes were noted in the firing profile evoked by 500 ms square current supra‐threshold stimuli. However, Aβ 500 nM treatment resulted in the hyperpolarization of the action potential (AP) threshold. In addition, treatment with Aβ at 500 nM depressed the after‐hyperpolarization that followed both a single AP or 50 Hz trains of a number of APs between 5 and 25. These data suggest that acute exposure to soluble Aβ oligomers affects IE properties of CA1 pyramidal neurons differently from outcomes seen in transgenic models of amyloidopathy. However, in both chronic and acute models, the IE changes are toward hyperexcitability, reinforcing the idea that amyloidopathy and increased incidence in seizures might be causally related in AD patients. © 2014 The Authors Hippocampus Published by Wiley Periodicals, Inc. PMID:25515596
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Nanoparticle for delivery of antisense γPNA oligomers targeting CCR5.
Bahal, Raman; McNeer, Nicole Ali; Ly, Danith H; Saltzman, W Mark; Glazer, Peter M
2013-01-01
The development of a new class of peptide nucleic acids (PNAs), i.e., gamma PNAs (γPNAs), creates the need for a general and effective method for its delivery into cells for regulating gene expression in mammalian cells. Here we report the antisense activity of a recently developed hydrophilic and biocompatible diethylene glycol (miniPEG)-based gamma peptide nucleic acid called MPγPNAs via its delivery by poly(lactide-co-glycolide) (PLGA)-based nanoparticle system. We show that MPγPNA oligomers designed to bind to the selective region of chemokine receptor 5 (CC R5) transcript, induce potent and sequence-specific antisense effects as compared with regular PNA oligomers. In addition, PLGA nanoparticle delivery of MPγPNAs is not toxic to the cells. The findings reported in this study provide a combination of γPNA technology and PLGA-based nanoparticle delivery method for regulating gene expression in live cells via the antisense mechanism.
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Directory of Open Access Journals (Sweden)
Qianqian Wang
Full Text Available EGCG possesses the ability of disaggregating the existing amyloid fibrils which were associated with many age-related degenerative diseases. However, the molecular mechanism of EGCG to disaggregate these fibrils is poorly known. In this work, to study the influence of EGCG on the full-length human islet amyloid polypeptide 1-37 (hIAPP1-37 oligomers, molecular dynamics simulations of hIAPP1-37 pentamer and decamer with EGCG were performed, respectively. The obtained results indicate that EGCG indeed destabilized the hIAPP1-37 oligomers. The nematic order parameter and secondary structure calculations coupled with the free-energy landscape indicate that EGCG broke the initial ordered pattern of two polymers, greatly reduced their β-sheet content and enlarged their conformational space. On this basis, three possible target sites were identified with the binding capacity order of S1>S2>S3. After a deeper analysis of each site, we found that S1 was the most possible site on which residues B-Ile26/Ala25, A-Phe23, B/C-Leu27 and E-Tyr37 played an important role for their binding. The proposal of this molecular mechanism can not only provide a prospective interaction figure between EGCG and β-sheet-rich fibrils of hIAPP1-37, but also is useful for further discovering other potential inhibitors.
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Study on Land Subsidence Incangzhou Area Basedon SENTINEL-1A/B Data
Zhou, H.; Wang, Y.; Yan, S.
2017-09-01
This paper, obtaining 39scenesof images of the Sentinel-1 A/B, monitored the Cangzhou area subsidence from Mar. 2015 to Dec. 2016 basing on using PS-InSAR technique. The annual average subsidence rate and accumulative subsidence were obtained. The results showed that the ground surface of Xian County,Cang County, Cangzhou urban area had a rebound trend; Qing County, the east of Cang County ,the west of Nanpi County and Dongguang County appeared obvious subsidence, and the accumulated subsidence in Hezhuang village of Dongguang County reached 47 mm. And from that the main reason leading to these obvious subsidence was over-exploitation of ground-water. At last, it analyzed the settlement of the High-Speed Railway (HR) which was north from the Machang town of QingCounty and south to the Lian town of Dongguang County in Cangzhou.The relative deformation of the HR between the two sections which was Lierzhuang village of Cang County and Chenxin village of Nanpi County arrived at 30 mm. Moreover, this paper discussed the application of Sentinel-1 A/B SAR images in monitoring urban land subsidence and the results provided important basic data for the relevant departments.
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Wang, Shan; Tian, Yu; Zhang, Jing-Yi; Xu, Hui-Bo; Zhou, Ping; Wang, Min; Lu, Sen-Bao; Luo, Yun; Wang, Min; Sun, Gui-Bo; Xu, Xu-Dong; Sun, Xiao-Bo
2018-01-01
Calenduloside E (CE), a natural triterpenoid compound isolated from Aralia elata, can protect against ox-LDL-induced human umbilical vein endothelial cell (HUVEC) injury in our previous reports. However, the exact targets and mechanisms of CE remain elusive. For the sake of resolving this question, we designed and synthesized a clickable activity-based probe (CE-P), which could be utilized to fish the functional targets in HUVECs using a gel-based strategy. Based on the previous studies of the structure-activity relationship (SAR), we introduced an alkyne moiety at the C-28 carboxylic group of CE, which kept the protective and anti-apoptosis activity. Via proteomic approach, one of the potential proteins bound to CE-P was identified as Hsp90AB1, and further verification was performed by pure recombinant Hsp90AB1 and competitive assay. These results demonstrated that CE could bind to Hsp90AB1. We also found that CE could reverse the Hsp90AB1 decrease after ox-LDL treatment. To make our results more convincing, we performed SPR analysis and the affinity kinetic assay showed that CE/CE-P could bind to Hsp90AB1 in a dose-dependent manner. Taken together, our research showed CE could probably bind to Hsp90AB1 to protect the cell injury, which might provide the basis for the further exploration of its cardiovascular protective mechanisms. For the sake of resolving this question, we designed and synthesized a clickable activity-based probe (CE-P), which could be utilized to fish the functional targets in HUVECs using a gel-based strategy. PMID:29875664
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Prokudina, E N; Semenova, N P; Chumakov, V M; Burtseva, E I; Slepushkin, A N
2003-01-01
A comparative analysis of involving the nucleocapsid protein (NP) into shaping-up of SDS-resistant oligomers was carried out presently in circulating epidemic strains of human influenza, viruses A and B. The study results of viral isolates obtained from clinical samples and recent standard strains revealed that the involvement of NP in the SDS-resistant oligomers, which are different in various subtypes of influenza A viruses. According to this sign, the human viruses A(9H3N2) are close to the avian ones, in which, as proved by us previously, virtually the entire NP transforms itself into the oligomers resistant to SDS. About 10-20% of NP are involved in shaping-up the virus influenza A(H1N1) of SDS-resistant oligomers. No SDS-resistant NP-oligomers were detected in influenza of type B. It is suggested that the prevalence of human viruses A(H3N2) in NP-oligomers are the peculiarities of NP structure and of the presence of the PB1 protein from avian influenza virus.
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Calvo-Rodríguez, María; García-Durillo, Mónica; Villalobos, Carlos; Núñez, Lucía
2016-07-22
The most important risk factor for Alzheimer's disease (AD) is aging. Neurotoxicity in AD has been linked to dyshomeostasis of intracellular Ca2+ induced by small aggregates of the amyloid-β peptide 1-42 (Aβ42 oligomers). However, how aging influences susceptibility to neurotoxicity induced by Aβ42 oligomers is unknown. In this study, we used long-term cultures of rat hippocampal neurons, a model of neuronal in vitro aging, to investigate the contribution of aging to Ca2+ dishomeostasis and neuron cell death induced by Aβ42 oligomers. In addition, we tested whether non-steroidal anti-inflammatory drugs (NSAIDs) and R-flurbiprofen prevent apoptosis acting on subcellular Ca2+ in aged neurons. We found that Aβ42 oligomers have no effect on young hippocampal neurons cultured for 2 days in vitro (2 DIV). However, they promoted apoptosis modestly in mature neurons (8 DIV) and these effects increased dramatically after 13 DIV, when neurons display many hallmarks of in vivo aging. Consistently, cytosolic and mitochondrial Ca2+ responses induced by Aβ42 oligomers increased dramatically with culture age. At low concentrations, NSAIDs and the enantiomer R-flurbiprofen lacking anti-inflammatory activity prevent Ca2+ overload and neuron cell death induced by Aβ42 oligomers in aged neurons. However, at high concentrations R-flurbiprofen induces apoptosis. Thus, Aβ42 oligomers promote Ca2+ overload and neuron cell death only in aged rat hippocampal neurons. These effects are prevented by low concentrations of NSAIDs and R-flurbiprofen acting on mitochondrial Ca2+ overload.
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Czech Academy of Sciences Publication Activity Database
Vraštil, J.; Matějka, Libor; Špaček, V.; Večeřa, M.; Prokůpek, L.
2005-01-01
Roč. 46, č. 25 (2005), s. 11232-11240 ISSN 0032-3861 Institutional research plan: CEZ:AV0Z40500505 Keywords : organic-inorganic hybrid * sol-gel process * oligomers Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.849, year: 2005
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Directory of Open Access Journals (Sweden)
Y. Tan
2012-01-01
Full Text Available Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including pyruvate, oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA. Acetic acid plays a central role in the aqueous oxidation of methylglyoxal and it is a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid (20 μM–10 mM was oxidized by OH radicals, and pyruvic acid and methylglyoxal experimental samples were analyzed using new analytical methods, in order to better understand the formation of SOA from acetic acid and methylglyoxal. Glyoxylic, glycolic, and oxalic acids formed from acetic acid and OH radicals. In contrast to the aqueous OH radical oxidation of methylglyoxal, the aqueous OH radical oxidation of acetic acid did not produce succinic acid and oligomers. This suggests that the methylgloxal-derived oligomers do not form through the acid catalyzed esterification pathway proposed previously. Using results from these experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.
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Imberdis, Thibaut; Ayrolles-Torro, Adeline; Duarte Rodrigues, Alysson; Torrent, Joan; Alvarez-Martinez, Maria Teresa; Kovacs, Gabor G; Verdier, Jean-Michel; Robitzer, Mike; Perrier, Véronique
2016-01-26
Prion diseases are characterized by the accumulation in the central nervous system of an abnormally folded isoform of the prion protein, named PrP(Sc). Aggregation of PrP(Sc) into oligomers and fibrils is critically involved in the pathogenesis of prion diseases. Oligomers are supposed to be the key neurotoxic agents in prion disease, so modulation of prion aggregation pathways with small molecules can be a valuable strategy for studying prion pathogenicity and for developing new diagnostic and therapeutic approaches. We previously identified thienyl pyrimidine compounds that induce SDS-resistant PrP(Sc) (rSDS-PrP(Sc)) oligomers in prion-infected samples. Due to the low effective doses of the thienyl pyrimidine hits, we synthesized a quaterthiophene-bis-triazine compound, called MR100 to better evaluate their diagnostic and therapeutic potentials. This molecule exhibits a powerful activity inducing rSDS-PrP(Sc) oligomers at nanomolar concentrations in prion-infected cells. Fluorescence interaction studies of MR100 with mouse PrP fibrils showed substantial modification of the spectrum, and the interaction was confirmed in vitro by production of rSDS-oligomer species upon incubation of MR100 with fibrils in SDS-PAGE gel. We further explored whether MR100 compound has a potential to be used in the diagnosis of prion diseases. Our results showed that: (i) MR100 can detect rSDS-oligomers in prion-infected brain homogenates of various species, including human samples from CJD patients; (ii) A protocol, called "Rapid Centrifugation Assay" (RCA), was developed based on MR100 property of inducing rSDS-PrP(Sc) oligomers only in prion-infected samples, and avoiding the protease digestion step. RCA allows the detection of both PK-sensitive and PK-resistant PrP(Sc) species in rodents samples but also from patients with different CJD forms (sporadic and new variant); (iii) A correlation could be established between the amount of rSDS-PrP(Sc) oligomers revealed by MR100 and the
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Mengerink, Y; Peters, R; Kerkhoff, M; Hellenbrand, J; Omloo, H; Andrien, J; Vestjens, M; van der Wal, S
2000-05-05
By separating the first six linear and cyclic oligomers of polyamide-6 on a reversed-phase high-performance liquid chromatographic system after sandwich injection, quantitative determination of these oligomers becomes feasible. Low-wavelength UV detection of the different oligomers and selective post-column reaction detection of the linear oligomers with o-phthalic dicarboxaldehyde (OPA) and 3-mercaptopropionic acid (3-MPA) are discussed. A general methodology for quantification of oligomers in polymers was developed. It is demonstrated that the empirically determined group-equivalent absorption coefficients and quench factors are a convenient way of quantifying linear and cyclic oligomers of nylon-6. The overall long-term performance of the method was studied by monitoring a reference sample and the calibration factors of the linear and cyclic oligomers.
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Cholesterol facilitates interactions between α-synuclein oligomers and charge-neutral membranes
DEFF Research Database (Denmark)
van Maarschalkerweerd, Andreas; Vetri, Valeria; Vestergaard, Bente
2015-01-01
composed of anionic lipids, while the more physiologically relevant zwitterionic lipids remain intact. We present experimental evidence for significant morphological changes in zwitterionic membranes containing cholesterol, induced by α-synuclein oligomers. Depending on the lipid composition, model...... of cholesterol for mediating interactions between physiologically relevant membranes and α-synuclein....
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Kim, YoungDoo; Choi, Hyunwoo; Lee, WonJae; Park, Hyejin; Kam, Tae-In; Hong, Se-Hoon; Nah, Jihoon; Jung, Sunmin; Shin, Bora; Lee, Huikyong; Choi, Tae-Yong; Choo, Hyosun; Kim, Kyung-Keun; Choi, Se-Young; Kayed, Rakez; Jung, Yong-Keun
2016-03-01
In neurodegenerative diseases like AD, tau forms neurofibrillary tangles, composed of tau protein. In the AD brain, activated caspases cleave tau at the 421th Asp, generating a caspase-cleaved form of tau, TauC3. Although TauC3 is known to assemble rapidly into filaments in vitro, a role of TauC3 in vivo remains unclear. Here, we generated a transgenic mouse expressing human TauC3 using a neuron-specific promoter. In this mouse, we found that human TauC3 was expressed in the hippocampus and cortex. Interestingly, TauC3 mice showed drastic learning and spatial memory deficits and reduced synaptic density at a young age (2-3months). Notably, tau oligomers as well as tau aggregates were found in TauC3 mice showing memory deficits. Further, i.p. or i.c.v. injection with methylene blue or Congo red, inhibitors of tau aggregation in vitro, and i.p. injection with rapamycin significantly reduced the amounts of tau oligomers in the hippocampus, rescued spine density, and attenuated memory impairment in TauC3 mice. Together, these results suggest that TauC3 facilitates early memory impairment in transgenic mice accompanied with tau oligomer formation, providing insight into the role of TauC3 in the AD pathogenesis associated with tau oligomers and a useful AD model to test drug candidates. Copyright © 2015 Elsevier Inc. All rights reserved.
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40 CFR 40.125-1 - Limitations on duration.
2010-07-01
... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Limitations on duration. 40.125-1 Section 40.125-1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE RESEARCH AND DEMONSTRATION GRANTS § 40.125-1 Limitations on duration. (a) [Reserved] (b) No...
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Dong, Chuanding; Hoppe, Harald; Beenken, Wichard J D
2016-06-02
Using density functional calculations with and without dispersion interaction, we studied the effects of linear octyl and branched 2-ethylhexyl side chains on the oligomer conformation of the conjugated copolymer poly(p-anthracene-ethynylene)-alt-poly(p-phenylene-vinylene). With dispersion included, the branched side chains can cause significant bending of the oligomer backbone, while without dispersion they induce mainly torsional disorder. The oligomers with mainly linear side chains keep good planarity when optimized with and without dispersion. Despite their dramatically different conformations, the calculated absorption spectra of the oligomers with various side chain combinations are very similar, indicating that the conformation of the copolymer is not the main reason for the experimentally observed different spectra of ordered and disordered phases.
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Li, Zeyang; Gao, Yang; Zhang, Minhong; Feng, Jinghai; Xiong, Yandan
2015-01-01
The aim of this study was to evaluate the effect of feeding Bacillus thuringiensis (Bt) rice expressing the Cry1Ab/1Ac protein on broiler chicken. The genetically modified (GM) Bt rice was compared with the corresponding non-GM rice regarding performance of feeding groups, their health status, relative organ weights, biochemical serum parameters and occurrence of Cry1Ab/1Ac gene fragments. One hundred and eighty day-old Arbor Acres female broilers with the same health condition were randomly allocated to the two treatments (6 replicate cages with 15 broilers in each cage per treatment). They received diets containing GM rice (GM group) or its parental non-GM rice (non-GM group) at 52-57% of the air-dried diet for 42 days. The results show that the transgenic rice had a similar nutrient composition as the non-GM rice and had no adverse effects on chicken growth, biochemical serum parameters and necropsy during the 42-day feeding period. In birds fed the GM rice, no transgenic gene fragments were detected in the samples of blood, liver, kidneys, spleen, jejunum, ileum, duodenum and muscle tissue. In conclusion, the results suggest that Bt rice expressing Cry1Ab/1Ac protein has no adverse effects on broiler chicken. Therefore, it can be considered as safe and used as feed source for broiler chicken.
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Supersymmetry theory of microphase separation in homopolymer-oligomer mixtures
International Nuclear Information System (INIS)
Olemskoi, Alexander; Krakovsky, Ivan; Savelyev, Alexey
2004-01-01
The mesoscopic structure of periodically alternating layers of stretched homopolymer chains surrounded by perpendicularly oriented oligomeric tails is studied for systems with both strong (ionic) and weak (hydrogen) interactions. We focus on the consideration of the distribution of oligomers along the homopolymer chains that is described by the effective equation of motion with the segment number playing the role of imaginary time. The supersymmetry technique is developed to consider associative hydrogen bonding, self-action effects, inhomogeneity, and temperature fluctuations in the oligomer distribution. Making use of the self-consistent approach allows one to explain experimentally observed temperature dependence of the structure period and the order-disorder transition temperature and period as functions of the oligomeric fraction for systems with different bonding strengths. A whole set of parameters of the model used is found for strong, intermediate, and weak coupled systems being Poly (4-vinyl pyridine)-dodecyl benzene sulfonic acid [P4VP-(DBSA) x ], P4VP-[Zn(DBS) 2 ] x , and P4VP- 3-pentadecyl Phenol x , respectively. A passage from the former two to the latter is shown to cause a crucial decrease in the magnitude of both parameters of hydrogen bonding and self-action, as well as the order-disorder transition temperature
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A hydrogel biosensor for high selective and sensitive detection of amyloid-beta oligomers
Directory of Open Access Journals (Sweden)
Sun LP
2018-02-01
Full Text Available Liping Sun,1 Yong Zhong,1 Jie Gui,1 Xianwu Wang,1 Xiaorong Zhuang,2 Jian Weng1 1Key Laboratory of Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University, 2Department of Neurology, The Affiliated Zhongshan Hospital of Xiamen University, Xiamen, People’s Republic of China Background: Alzheimer’s disease (AD is a neurodegenerative disorder characterized by progressive cognitive and memory impairment. It is the most common neurological disease that causes dementia. Soluble amyloid-beta oligomers (AβO in blood or cerebrospinal fluid (CSF are the pathogenic biomarker correlated with AD. Methods: A simple electrochemical biosensor using graphene oxide/gold nanoparticles (GNPs hydrogel electrode was developed in this study. Thiolated cellular prion protein (PrPC peptide probe was immobilized on GNPs of the hydrogel electrode to construct an AβO biosensor. Electrochemical impedance spectroscopy was utilized for AβO analysis. Results: The specific binding between AβO and PrPC probes on the hydrogel electrode resulted in an increase in the electron-transfer resistance. The biosensor showed high specificity and sensitivity for AβO detection. It could selectively differentiate AβO from amyloid-beta (Aβ monomers or fibrils. Meanwhile, it was highly sensitive to detect as low as 0.1 pM AβO in artificial CSF or blood plasma. The linear range for AβO detection is from 0.1 pM to 10 nM. Conclusion: This biosensor could be used as a cost-effective tool for early diagnosis of AD due to its high electrochemical performance and bionic structure. Keywords: Alzheimer’s disease, amyloid-beta oligomer, graphene, gold nanoparticles, biosensor
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Directory of Open Access Journals (Sweden)
Shuanghui Yin
Full Text Available Foot-and-mouth disease (FMD, caused by FMD virus (FMDV, is a highly contagious viral disease affecting cloven-hoofed animals. Camelids have a unique immunoglobulin profile, with the smallest functional heavy-chain antibodies (sdAb or VHH naturally devoid of light chains with antigen-binding capacity. We screened and characterized five sdAbs against FMDV by immunized library from C. bactrianus with Asia 1 virus-like particles (VLPs. Three of five recombinant sdAbs were stably expressed in E.coli, remained highly soluble, and were serotype-specific for VP1 protein of FMDV Asia 1 by ELISA. These failed to completely neutralize the Asia 1 virus. According to the KD value of binding affinity to three sdAbs, which ranged from 0.44 to 0.71 nm by SPR, sdAb-C6 was selected and conjugated with Zn/CdSe quantum dots (QDs to form a QDs-C6 probe, which was used to trace and image the subcellular location of FMDV in BHK-21 cells. The results show that FMD virions were observed from 3 h.p.i., and most of virions were distributed on one side of the nucleus in the cytoplasm. We demonstrate the utility of sdAbs as functionalized QDs are powerful tools for FMDV research.
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Rosenman, David J; Connors, Christopher R; Chen, Wen; Wang, Chunyu; García, Angel E
2013-09-23
Amyloid β (Aβ) peptides are a primary component of fibrils and oligomers implicated in the etiology of Alzheimer's disease (AD). However, the intrinsic flexibility of these peptides has frustrated efforts to investigate the secondary and tertiary structure of Aβ monomers, whose conformational landscapes directly contribute to the kinetics and thermodynamics of Aβ aggregation. In this work, de novo replica exchange molecular dynamics (REMD) simulations on the microseconds-per-replica timescale are used to characterize the structural ensembles of Aβ42, Aβ40, and M35-oxidized Aβ42, three physiologically relevant isoforms with substantially different aggregation properties. J-coupling data calculated from the REMD trajectories were compared to corresponding NMR-derived values acquired through two different pulse sequences, revealing that all simulations converge on the order of hundreds of nanoseconds-per-replica toward ensembles that yield good agreement with experiment. Though all three Aβ species adopt highly heterogeneous ensembles, these are considerably more structured compared to simulations on shorter timescales. Prominent in the C-terminus are antiparallel β-hairpins between L17-A21, A30-L36, and V39-I41, similar to oligomer and fibril intrapeptide models that expose these hydrophobic side chains to solvent and may serve as hotspots for self-association. Compared to reduced Aβ42, the absence of a second β-hairpin in Aβ40 and the sampling of alternate β topologies by M35-oxidized Aβ42 may explain the reduced aggregation rates of these forms. A persistent V24-K28 bend motif, observed in all three species, is stabilized by buried backbone to side-chain hydrogen bonds with D23 and a cross-region salt bridge between E22 and K28, highlighting the role of the familial AD-linked E22 and D23 residues in Aβ monomer folding. These characterizations help illustrate the conformational landscapes of Aβ monomers at atomic resolution and provide insight into
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Directory of Open Access Journals (Sweden)
Djoko W. Soeatmadji
2005-12-01
Full Text Available Clinically, type 1 diabetes may presents as type 2 diabetes which sometimes not easily differentiated. Perhaps only autoimmune markers of β-cells destruction could differentiate those two clinical conditions. Due to extremely high cost ( $ 150/test, examination of anti-glutamic acid decarboxylase-65 auto-antibodies (anti-GAD65Abs may not be routinely performed in most, if not all, clinical laboratories in Indonesia. Hence, the production of anti-GAD65 Abs reagent in Indonesia may reduce the cost and improve the quality of diabetes care in Indonesia. We produce reagent to detect anti-GAD65-Abs using bovine brain tissue as source of GAD enzyme in 3 steps. Step 1, isolation, purification of GAD65 from bovine brain tissue and used it as a primary antigen to stimulate the generation of anti-GAD65 antibodies in Wistar rat. Step 2, the purified GAD65 antibodies were than used as a secondary antibody to induce the production of anti-anti-GAD65-antibodies in Wistar rat and rabbit. Step 3. Labeling anti-anti GAD65-antibodies with alkaline phoshpatase and peroxidase, and detecting anti-GAD65Abs previously detected using commercial kit. The anti-anti-GAD65- antibodies reagent produced in our laboratories successfully identify anti-GAD65-Abs of type 1 diabetic patients previously detected with commercial reagent. (Med J Indones 2005; 14: 197-203Keywords: GAD, type-1 Diabetes
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Towards directional assembly of hierarchical structures: aniline oligomers as the model precursors
Czech Academy of Sciences Publication Activity Database
Zhao, Y.; Stejskal, Jaroslav; Wang, J.
2013-01-01
Roč. 5, č. 7 (2013), s. 2620-2626 ISSN 2040-3364 R&D Projects: GA ČR GAP205/12/0911 Institutional support: RVO:61389013 Keywords : aniline oligomers * hierarchical nanostructures * microflowers Subject RIV: CD - Macromolecular Chemistry Impact factor: 6.739, year: 2013
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Side-chain degradation of ultrapure π-conjugated oligomers: implications for organic electronics
Abbel, R.J.; Wolffs, M.; Bovee, R.A.A.; Dongen, van J.L.J.; Lou, X.W.; Henze, O.; Feast, W.J.; Meijer, E.W.; Schenning, A.P.H.J.
2009-01-01
The degrdn. of two defect-free pi-conjugated oligomers and the participation of their solubilizing side chains in the process are studied in unprecedented detail. The detected intermediate products reveal a mechanism of successive shortening of alkyl and oligo(ethylene glycol) substituents.
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Acute respiratory distress syndrome 40 years later: time to revisit its definition.
Phua, Jason; Stewart, Thomas E; Ferguson, Niall D
2008-10-01
Acute respiratory distress syndrome is a common disorder associated with significant mortality and morbidity. The aim of this article is to critically evaluate the definition of acute respiratory distress syndrome and examine the impact the definition has on clinical practice and research. Articles from a MEDLINE search (1950 to August 2007) using the Medical Subject Heading respiratory distress syndrome, adult, diagnosis, limited to the English language and human subjects, their relevant bibliographies, and personal collections, were reviewed. The definition of acute respiratory distress syndrome is important to researchers, clinicians, and administrators alike. It has evolved significantly over the last 40 years, culminating in the American-European Consensus Conference definition, which was published in 1994. Although the American-European Consensus Conference definition is widely used, it has some important limitations that may impact on the conduct of clinical research, on resource allocation, and ultimately on the bedside management of such patients. These limitations stem partially from the fact that as defined, acute respiratory distress syndrome is a heterogeneous entity and also involve the reliability and validity of the criteria used in the definition. This article critically evaluates the American-European Consensus Conference definition and its limitations. Importantly, it highlights how these limitations may contribute to clinical trials that have failed to detect a potential true treatment effect. Finally, recommendations are made that could be considered in future definition modifications with an emphasis on the significance of accurately identifying the target population in future trials and subsequently in clinical care. How acute respiratory distress syndrome is defined has a significant impact on the results of randomized, controlled trials and epidemiologic studies. Changes to the current American-European Consensus Conference definition are
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Moghimi, Sasan; Hamzeh, Nikoo; Mohammadi, Massood; Khatibi, Nassim; Bowd, Christopher; Weinreb, Robert N
2018-05-01
To compare outcomes of phacoemulsification combined with viscocanalostomy, endocyclophotocoagulation (ECP), or ab interno trabulectomy for intraocular pressure (IOP) control and safety in eyes with open-angle glaucoma and visually significant cataract. Farabi Eye Hospital, Tehran, Iran. Retrospective case series. Medical records of patients who had combined surgery and were followed for at least 1 year were reviewed. Complete success, postoperative IOP, number of medications at each visit, and complications were evaluated and compared before and after adjustments for confounders. Forty-six eyes had combined phacoviscocanalostomy, 35 had phaco-ECP, and 28 eyes phaco-ab interno trabulectomy. The groups were matched for baseline IOP (P = .24). At the final follow-up (mean 17.2 months ± 5.5 [SD]), the phacoviscocanalostomy group had the lowest mean IOP (13.5 ± 4.7 mm Hg, 29% decrease) (P = .01). There was no significant difference in the final IOP between phaco-ECP and phaco-ab interno trabulectomy (16.4 ± 3.9 mm Hg, 20% decrease versus 15.8 ± 4.2 mm Hg, 15% decrease) (P = .88). The reduction in the number of medications was greater with phacoviscocanalostomy (77%) than with phaco-ECP (40%) and phaco-ab interno trabulectomy (44%) (P = .01). Phacoemulsification-ab interno trabulectomy had the fewest complications. Intraocular pressure spikes were more frequent in the phaco-ECP group (20%) than in the other groups (4%) (P = .05). All procedures significantly lowered IOP. Phacoemulsification-ab interno trabulectomy resulted in fewest complications and phacoviscocanalostomy led to the largest IOP drop and largest reduction of medications. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
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Collin, Vanessa; Flamand, Louis
2017-06-26
Unlike other human herpesviruses, human herpesvirus 6A and 6B (HHV-6A/B) infection can lead to integration of the viral genome in human chromosomes. When integration occurs in germinal cells, the integrated HHV-6A/B genome can be transmitted to 50% of descendants. Such individuals, carrying one copy of the HHV-6A/B genome in every cell, are referred to as having inherited chromosomally-integrated HHV-6A/B (iciHHV-6) and represent approximately 1% of the world's population. Interestingly, HHV-6A/B integrate their genomes in a specific region of the chromosomes known as telomeres. Telomeres are located at chromosomes' ends and play essential roles in chromosomal stability and the long-term proliferative potential of cells. Considering that the integrated HHV-6A/B genome is mostly intact without any gross rearrangements or deletions, integration is likely used for viral maintenance into host cells. Knowing the roles played by telomeres in cellular homeostasis, viral integration in such structure is not likely to be without consequences. At present, the mechanisms and factors involved in HHV-6A/B integration remain poorly defined. In this review, we detail the potential biological and medical impacts of HHV-6A/B integration as well as the possible chromosomal integration and viral excision processes.
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DEFF Research Database (Denmark)
Nielsen, C H; Antonsen, S; Matthiesen, S H
1997-01-01
cells using the monoclonal antibody (mAb) 3D9 resulted in a 1.9-fold increase in the IC-elicited PMN RB after 5 min of incubation, rising to 3.1-fold after 40 min. This enhancement was not due to increased IC deposition on PMN. Blockade of CR3 abrogated the mAb 3D9-induced rise in RB activity...... and inhibited the IC binding to PMN in a whole blood cell preparation, with or without mAb 3D9, by approximately 40% from 15-40 min while reducing their RB over 40 min to approximately one third. Blockade of CR1 on either erythrocytes (E) or leukocytes, before mixing the populations, revealed...... that the potentiation of the RB by mAb 3D9 was associated with abrogation of E-CR1 function, whereas blockade of leukocyte-CR1 had a diminishing effect. Exposure to IC at high concentrations induced release of both specific and azurophilic granule contents from PMN. The latter was CR3 dependent in that blockade...
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Hong, Bingbing; Panagiotopoulos, Athanassios Z.
2012-01-01
A molecular model of silica nanoparticles grafted with poly(ethylene oxide) oligomers has been developed for predicting the transport properties of nanoparticle organic-hybrid materials (NOHMs). Ungrafted silica nanoparticles in a medium of poly(ethylene
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Therapeutic activity of multiple common γ-chain cytokine inhibition in acute and chronic GVHD.
Hechinger, Anne-Kathrin; Smith, Benjamin A H; Flynn, Ryan; Hanke, Kathrin; McDonald-Hyman, Cameron; Taylor, Patricia A; Pfeifer, Dietmar; Hackanson, Björn; Leonhardt, Franziska; Prinz, Gabriele; Dierbach, Heide; Schmitt-Graeff, Annette; Kovarik, Jiri; Blazar, Bruce R; Zeiser, Robert
2015-01-15
The common γ chain (CD132) is a subunit of the interleukin (IL) receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Because levels of several of these cytokines were shown to be increased in the serum of patients developing acute and chronic graft-versus-host disease (GVHD), we reasoned that inhibition of CD132 could have a profound effect on GVHD. We observed that anti-CD132 monoclonal antibody (mAb) reduced acute GVHD potently with respect to survival, production of tumor necrosis factor, interferon-γ, and IL-6, and GVHD histopathology. Anti-CD132 mAb afforded protection from GVHD partly via inhibition of granzyme B production in CD8 T cells, whereas exposure of CD8 T cells to IL-2, IL-7, IL-15, and IL-21 increased granzyme B production. Also, T cells exposed to anti-CD132 mAb displayed a more naive phenotype in microarray-based analyses and showed reduced Janus kinase 3 (JAK3) phosphorylation upon activation. Consistent with a role of JAK3 in GVHD, Jak3(-/-) T cells caused less severe GVHD. Additionally, anti-CD132 mAb treatment of established chronic GVHD reversed liver and lung fibrosis, and pulmonary dysfunction characteristic of bronchiolitis obliterans. We conclude that acute GVHD and chronic GVHD, caused by T cells activated by common γ-chain cytokines, each represent therapeutic targets for anti-CD132 mAb immunomodulation. © 2015 by The American Society of Hematology.
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Kinesin-2 KIF3AB exhibits novel ATPase characteristics.
Albracht, Clayton D; Rank, Katherine C; Obrzut, Steven; Rayment, Ivan; Gilbert, Susan P
2014-10-03
KIF3AB is an N-terminal processive kinesin-2 family member best known for its role in intraflagellar transport. There has been significant interest in KIF3AB in defining the key principles that underlie the processivity of KIF3AB in comparison with homodimeric processive kinesins. To define the ATPase mechanism and coordination of KIF3A and KIF3B stepping, a presteady-state kinetic analysis was pursued. For these studies, a truncated murine KIF3AB was generated. The results presented show that microtubule association was fast at 5.7 μm(-1) s(-1), followed by rate-limiting ADP release at 12.8 s(-1). ATP binding at 7.5 μm(-1) s(-1) was followed by an ATP-promoted isomerization at 84 s(-1) to form the intermediate poised for ATP hydrolysis, which then occurred at 33 s(-1). ATP hydrolysis was required for dissociation of the microtubule·KIF3AB complex, which was observed at 22 s(-1). The dissociation step showed an apparent affinity for ATP that was very weak (K½,ATP at 133 μm). Moreover, the linear fit of the initial ATP concentration dependence of the dissociation kinetics revealed an apparent second-order rate constant at 0.09 μm(-1) s(-1), which is inconsistent with fast ATP binding at 7.5 μm(-1) s(-1) and a Kd ,ATP at 6.1 μm. These results suggest that ATP binding per se cannot account for the apparent weak K½,ATP at 133 μm. The steady-state ATPase Km ,ATP, as well as the dissociation kinetics, reveal an unusual property of KIF3AB that is not yet well understood and also suggests that the mechanochemistry of KIF3AB is tuned somewhat differently from homodimeric processive kinesins. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.
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The Effect of H2SO4 Concentration on the Ionic Conductivity of Liquid PMMA Oligomer
International Nuclear Information System (INIS)
Norashima Kamaluddin; Famiza Abdul Latif; Han, C.C.; Ruhani Ibrahim; Sharil Fadli Mohamad Zamri; Norashima Kamaluddin; Famiza Abdul Latif; Han, C.C.; Ruhani Ibrahim; Sharil Fadli Mohamad Zamri
2015-01-01
To date gel and film type polymer electrolytes have been widely synthesized due to their wide range of electrical properties. However these types of polymer electrolytes exhibit poor mechanical stability and poor electrode-electrolyte contact hence deprive the overall performance of a battery system. Therefore, in order to indulge the advantages of polymer as electrolyte, a new class of polymer electrolyte was synthesized and investigated. In this study, liquid poly(methyl methacrylate) (PMMA) electrolyte was synthesized using the simplest free radical polymerization technique using benzoyl peroxide as the initiator. At this stage, it was found that this liquid PMMA oligomer (MW=3000 g/ mole) has a potential as electrolyte in electrochemical devices. It was found that an ionic conductivity of ∼10 -7 S/ cm at room temperature can be achieved when only small volume of high molarity of sulfuric acid (H 2 SO 4 ) was doped in the liquid PMMA oligomer. The properties of this liquid PMMA oligomer were further investigated using Fourier Transform Infrared Spectroscopy (FTIR). (author)
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Hydrogen bonding as the origin of the switching behavior in dithiolated phenylene-vinylene oligomers
Obodo, Tobechukwu Joshua; Gkionis, Konstantinos; Rungger, Ivan; Sanvito, Stefano; Schwingenschlö gl, Udo
2013-01-01
We investigate theoretically the switching behavior of a dithiolated phenylene-vinylene oligomer sandwiched between Au(111) electrodes using self-interaction corrected density-functional theory combined with the nonequilibrium Green
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Immunomodulatory effects of intravenous bis-1 f(ab')(2) administration in renal-cell cancer-patients
Janssen, R. A. J.; Kroesen, B. J.; Mesander, G.; Sleijfer, D. T.; The, T. Hauw; Mulder, N. H.; de Leij, L
We report the immunomodulatory effects of an intravenous treatment with F(ab')(2) fragments of the bispecific monoclonal antibody BIS-1 during subcutaneous recombinant interleukin 2 (rIL-2) therapy of renal cell cancer (RCC) patients. BIS-1 is directed against both the CD3 antigen on T cells and the
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Saarenhovi, Maria; Salo, Pia; Scheinin, Mika; Lehto, Jussi; Lovró, Zsófia; Tiihonen, Kirsti; Lehtinen, Markus J; Junnila, Jouni; Hasselwander, Oliver; Tarpila, Anneli; Raitakari, Olli T
2017-10-27
The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD). This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomised to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated. With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD. A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the
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Takagi, Hiroyuki; Oumi, Yasunori; Uozumi, Toshiya; Masuda, Takashi; Sano, Tsuneji
2001-01-01
The possibility of the synthesis of 1, 4-dioxan-2-one (p-dioxanon) by carbonylation of 1, 3-dioxolane (cyclic ether) over Nafion® NR-50 cation-exchange resin catalyst was investigated. 1, 4-Dioxan-2-one, one of the cyclic esterethers used as a monomer of polyester, was obtained by depolymerization of polyester oligomers. The maximum yield (40%) of 1, 4-dioxan-2-one was achieved under reaction conditions of 25MPa initial PCO, 120°C reaction temperature and 4h reaction time.
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Directory of Open Access Journals (Sweden)
Seth M. Daly
2017-11-01
Full Text Available In late 2015, the first example of a transferrable polymyxin resistance mechanism in Gram-negative pathogens, MCR-1, was reported. Since that report, MCR-1 has been described to occur in many Gram-negative pathogens, and the mechanism of MCR-1-mediated resistance was rapidly determined: an ethanolamine is attached to lipid A phosphate groups, rendering the membrane more electropositive and repelling positively charged polymyxins. Acquisition of MCR-1 is clinically significant because polymyxins are frequently last-line antibiotics used to treat extensively resistant organisms, so acquisition of this mechanism might lead to pan-resistant strains. Therefore, the ability to inhibit MCR-1 and restore polymyxin sensitivity would be an important scientific advancement. Peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs are antisense molecules that were designed to target mRNA, preventing translation. Peptide conjugation enhances cellular entry, but they are positively charged, so we tested our lead antibacterial PPMOs by targeting an essential Escherichia coli gene, acpP, and demonstrated that they were still effective in mcr-1-positive E. coli strains. We then designed and synthesized two PPMOs targeted to mcr-1 mRNA. Five clinical mcr-1-positive E. coli strains were resensitized to polymyxins by MCR-1 inhibition, reducing MICs 2- to 16-fold. Finally, therapeutic dosing of BALB/c mice with MCR-1 PPMO combined with colistin in a sepsis model reduced morbidity and bacterial burden in the spleen at 24 h and offered a survival advantage out to 5 days. This is the first example of a way to modulate colistin resistance with an antisense approach and may be a viable strategy to combat this globally emerging antibiotic resistance threat.
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Directory of Open Access Journals (Sweden)
Christiane E. Kupper
2012-05-01
Full Text Available The importance of glycans in biological systems is highlighted by their various functions in physiological and pathological processes. Many glycan epitopes on glycoproteins and glycolipids are based on N-acetyllactosamine units (LacNAc; Galβ1,4GlcNAc and often present on extended poly-LacNAc glycans ([Galβ1,4GlcNAc]n. Poly-LacNAc itself has been identified as a binding motif of galectins, an important class of lectins with functions in immune response and tumorigenesis. Therefore, the synthesis of natural and modified poly-LacNAc glycans is of specific interest for binding studies with galectins as well as for studies of their possible therapeutic applications. We present the oxidation by galactose oxidase and subsequent chemical or enzymatic modification of terminal galactose and N-acetylgalactosamine residues of poly-N-acetyllactosamine (poly-LacNAc oligomers and N,N-diacetyllactosamine (LacDiNAc by galactose oxidase. Product formation starting from different poly-LacNAc oligomers was characterised and optimised regarding formation of the C6-aldo product. Further modification of the aldehyde containing glycans, either by chemical conversion or enzymatic elongation, was established. Base-catalysed β-elimination, coupling of biotin–hydrazide with subsequent reduction to the corresponding hydrazine linkage, and coupling by reductive amination to an amino-functionalised poly-LacNAc oligomer were performed and the products characterised by LC–MS and NMR analysis. Remarkably, elongation of terminally oxidised poly-LacNAc glycans by β3GlcNAc- and β4Gal-transferase was also successful. In this way, a set of novel, modified poly-LacNAc oligomers containing terminally and/or internally modified galactose residues were obtained, which can be used for binding studies and various other applications.
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Atomistic simulation of CO 2 solubility in poly(ethylene oxide) oligomers
Hong, Bingbing
2013-10-02
We have performed atomistic molecular dynamics simulations coupled with thermodynamic integration to obtain the excess chemical potential and pressure-composition phase diagrams for CO2 in poly(ethylene oxide) oligomers. Poly(ethylene oxide) dimethyl ether, CH3O(CH 2CH2O)nCH3 (PEO for short) is a widely applied physical solvent that forms the major organic constituent of a class of novel nanoparticle-based absorbents. Good predictions were obtained for pressure-composition-density relations for CO2 + PEO oligomers (2 ≤ n ≤ 12), using the Potoff force field for PEO [J. Chem. Phys. 136, 044514 (2012)] together with the TraPPE model for CO2 [AIChE J. 47, 1676 (2001)]. Water effects on Henrys constant of CO2 in PEO have also been investigated. Addition of modest amounts of water in PEO produces a relatively small increase in Henrys constant. Dependence of the calculated Henrys constant on the weight percentage of water falls on a temperature-dependent master curve, irrespective of PEO chain length. © 2013 Taylor & Francis.
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QIAD assay for quantitating a compound’s efficacy in elimination of toxic Aβ oligomers
Brener, Oleksandr; Dunkelmann, Tina; Gremer, Lothar; van Groen, Thomas; Mirecka, Ewa A.; Kadish, Inga; Willuweit, Antje; Kutzsche, Janine; Jürgens, Dagmar; Rudolph, Stephan; Tusche, Markus; Bongen, Patrick; Pietruszka, Jörg; Oesterhelt, Filipp; Langen, Karl-Josef; Demuth, Hans-Ulrich; Janssen, Arnold; Hoyer, Wolfgang; Funke, Susanne A.; Nagel-Steger, Luitgard; Willbold, Dieter
2015-01-01
Strong evidence exists for a central role of amyloid β-protein (Aβ) oligomers in the pathogenesis of Alzheimer’s disease. We have developed a fast, reliable and robust in vitro assay, termed QIAD, to quantify the effect of any compound on the Aβ aggregate size distribution. Applying QIAD, we studied the effect of homotaurine, scyllo-inositol, EGCG, the benzofuran derivative KMS88009, ZAβ3W, the D-enantiomeric peptide D3 and its tandem version D3D3 on Aβ aggregation. The predictive power of the assay for in vivo efficacy is demonstrated by comparing the oligomer elimination efficiency of D3 and D3D3 with their treatment effects in animal models of Alzheimer´s disease. PMID:26394756
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Ab initio study of isomerism in molecular ions Li2AB+ with 10 valence electrons
International Nuclear Information System (INIS)
Charkin, O.P.; Mak-Ki, M.L.; Shlojer, P.R.
1997-01-01
Ab initio calculations of surfaces of Li 2 AB + molecular ion potential energy with biatomic anions AB - with 10 valence electrons have been made in the framework of approximations MP2/6-31G 1 /HF/6-31G*+ZPE(HF/6-31G*) and MP4SDTQ/631G*//MP2/6-31G*+ZPE(MP2/6-31G*). Influence of electron correlation on the accuracy of calculations of their structural and vibrational characteristics is studied. The following most favourable structures have been found: linear for Li 2 BO + , Li 2 CN + , and bent one for Li 2 BS + , with cations coordinated at different anion atoms; onium one for AlOLi 2 + , AlSLi 2 + , SiNLi 2 + and SiPLi 2 + with both cations at electronegative atom of anion
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Horvath, Istvan; Sellstedt, Magnus; Weise, Christoph; Nordvall, Lina-Maria; Krishna Prasad, G; Olofsson, Anders; Larsson, Göran; Almqvist, Fredrik; Wittung-Stafshede, Pernilla
2013-04-15
In a recent study we discovered that a ring-fused 2-pyridone compound triggered fibrillization of a key protein in Parkinson's disease, α-synuclein. To reveal how variations in compound structure affect protein aggregation, we now prepared a number of strategic analogs and tested their effects on α-synuclein amyloid fiber formation in vitro. We find that, in contrast to the earlier templating effect, some analogs inhibit α-synuclein fibrillization. For both templating and inhibiting compounds, the key species formed in the reactions are α-synuclein oligomers that contain compound. Despite similar macroscopic appearance, the templating and inhibiting oligomers are distinctly different in secondary structure content. When the inhibitory oligomers are added in seed amounts, they inhibit fresh α-synuclein aggregation reactions. Our study demonstrates that small chemical changes to the same central fragment can result in opposite effects on protein aggregation. Copyright © 2013 Elsevier Inc. All rights reserved.
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Bush, Sean P; Ruha, Anne-Michelle; Seifert, Steven A; Morgan, David L; Lewis, Brandon J; Arnold, Thomas C; Clark, Richard F; Meggs, William J; Toschlog, Eric A; Borron, Stephen W; Figge, Gary R; Sollee, Dawn R; Shirazi, Farshad M; Wolk, Robert; de Chazal, Ives; Quan, Dan; García-Ubbelohde, Walter; Alagón, Alejandro; Gerkin, Richard D; Boyer, Leslie V
2015-01-01
Crotalidae Polyvalent Immune Fab (Ovine) has been the only antivenom commercially available in the US since 2007 for treatment of Crotalinae envenomation. Late coagulopathy can occur or recur after clearance of Fab antivenom, often after hospital discharge, lasting in some cases more than 2 weeks. There have been serious, even fatal, bleeding complications associated with recurrence phenomena. Frequent follow-up is required, and additional intervention or hospitalization is often necessary. F(ab')2 immunoglobulin derivatives have longer plasma half life than do Fab. We hypothesized that F(ab')2 antivenom would be superior to Fab in the prevention of late coagulopathy following treatment of patients with Crotalinae envenomation. We conducted a prospective, double-blind, randomized clinical trial, comparing late coagulopathy in snakebitten patients treated with F(ab')2 with maintenance doses [F(ab')2/F(ab')2], or F(ab')2 with placebo maintenance doses [F(ab')2/placebo], versus Fab with maintenance doses [Fab/Fab]. The primary efficacy endpoint was coagulopathy (platelet count Fab/Fab cohort experienced late coagulopathy versus 4/39 (10.3%, p < 0.05) in the F(ab')2/F(ab')2 cohort and 2/38 (5.3%, p < 0.05) in the F(ab')2/placebo cohort. The lowest heterologous protein exposure was with F(ab')2/placebo. No serious adverse events were related to study drug. In each study arm, one patient experienced an acute serum reaction and one experienced serum sickness. In this study, management of coagulopathic Crotalinae envenomation with longer-half-life F(ab')2 antivenom, with or without maintenance dosing, reduced the risk of subacute coagulopathy and bleeding following treatment of envenomation.
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Chakravarthy, Balu; Ito, Shingo; Atkinson, Trevor; Gaudet, Chantal; Ménard, Michel; Brown, Leslie; Whitfield, James
2014-03-14
The synthetic ~5 kDa ABP (amyloid-ß binding peptide) consists of a region of the 228 kDa human pericentrioloar material-1 (PCM-1) protein that selectively and avidly binds in vitro Aβ1-42 oligomers, believed to be key co-drivers of Alzheimer's disease (AD), but not monomers (Chakravarthy et al., (2013) [3]). ABP also prevents Aß1-42 from triggering the apoptotic death of cultured human SHSY5Y neuroblasts, likely by sequestering Aß oligomers, suggesting that it might be a potential AD therapeutic. Here we support this possibility by showing that ABP also recognizes and binds Aβ1-42 aggregates in sections of cortices and hippocampi from brains of AD transgenic mice and human AD patients. More importantly, ABP targets Aβ1-42 aggregates when microinjected into the hippocampi of the brains of live AD transgenic mice. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.
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International Nuclear Information System (INIS)
Qi, Zeng; Ying-Liang, Liu; Kang, Meng; Xiang-Jie, Zhao; Shu-Feng, Wang; Qi-Huang, Gong
2009-01-01
We investigate the photo-physical properties of a series of triphenylamine-based oligomers by steady-state and picosecond transient fluorescence measurements in solvents. The oligomers are composed alternatively with triphenylamine and phenylene/thiophene/furan group, bridged by vinyl group (PNB/PNT/PNF). Their fluorescence spectra show bathochromic phenomenon with solvent polarity and viscosity increasing. The fluorescence decays are bi-exponential for PNB and PNT, and tri-exponential for PNF in THF and aniline. The strong viscosity dependence suggests conformational relaxation along the PNF chain after photo excitation. (condensed matter: electronicstructure, electrical, magnetic, and opticalproperties)
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Directory of Open Access Journals (Sweden)
Jayakumar Rajadas
Full Text Available Enhanced production of a 42-residue beta amyloid peptide (Aβ(42 in affected parts of the brain has been suggested to be the main causative factor for the development of Alzheimer's Disease (AD. The severity of the disease depends not only on the amount of the peptide but also its conformational transition leading to the formation of oligomeric amyloid-derived diffusible ligands (ADDLs in the brain of AD patients. Despite being significant to the understanding of AD mechanism, no atomic-resolution structures are available for these species due to the evanescent nature of ADDLs that hinders most structural biophysical investigations. Based on our molecular modeling and computational studies, we have designed Met35Nle and G37p mutations in the Aβ(42 peptide (Aβ(42Nle35p37 that appear to organize Aβ(42 into stable oligomers. 2D NMR on the Aβ(42Nle35p37 peptide revealed the occurrence of two β-turns in the V24-N27 and V36-V39 stretches that could be the possible cause for the oligomer stability. We did not observe corresponding NOEs for the V24-N27 turn in the Aβ(21-43Nle35p37 fragment suggesting the need for the longer length amyloid peptide to form the stable oligomer promoting conformation. Because of the presence of two turns in the mutant peptide which were absent in solid state NMR structures for the fibrils, we propose, fibril formation might be hindered. The biophysical information obtained in this work could aid in the development of structural models for toxic oligomer formation that could facilitate the development of therapeutic approaches to AD.
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Wu, Song; Wu, Xiaoqiong; Zhu, Wu; Cai, Wei-Jun; Schaper, Jutta; Schaper, Wolfgang
2010-10-01
Growth factors are viewed as main arteriogenic stimulators for collateral vessel growth. However, the information about their native expression and distribution in collateral vessels is still limited. This study was designed to profile expression of acidic and basic FGF, platelet-derived growth factor (PDGF-AB) and vascular endothelial growth factor (VEGF-A) and its receptor, fetal liver kinase-1 (Flk-1) during arteriogenesis by confocal immunofluorescence in both dog ameroid constrictor model and rabbit arteriovenous shunt model of arteriogenesis. We found that: (1) in normal arteries (NA) in dog heart, aFGF, bFGF, and PDGF-AB all were mainly expressed in endothelial cells (EC) and media smooth muscle cells (SMC), but the expression of aFGF was very weak, with those of the other two being moderate; (2) in collateral arteries (CAs), aFGF, bFGF, and PDGF-AB all were significantly upregulated (P growth factors, aFGF, bFGF, and PDGF-AB are significantly upregulated in collateral vessels in dog heart, and enhanced VEGF-A and its receptor, Flk-1, are associated with rapid and lasting increased shear stress. These findings suggest that endogenous production of growth factors could be an important factor promoting collateral vessel growth.
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Using Ab-Initio Calculations to Appraise Stm-Based - and Kink-Formation Energies
Feibelman, Peter J.
2001-03-01
Ab-initio total energies can and should be used to test the typically model-dependent results of interpreting STM morphologies. The benefits of such tests are illustrated here by ab-initio energies of step- and kink-formation on Pb and Pt(111) which show that the STM-based values of the kink energies must be revised. On Pt(111), the computed kink-energies for (100)- and (111)-microfacet steps are about 0.25 and 0.18 eV. These results imply a specific ratio of formation energies for the two step types, namely 1.14, in excellent agreement with experiment. If kink-formation actually cost the same energy on the two step types, an inference drawn from scanning probe observations of step wandering,(M. Giesen et al., Surf. Sci. 366, 229(1996).) this ratio ought to be 1. In the case of Pb(111), though computed energies to form (100)- and (111)-microfacet steps agree with measurement, the ab-initio kink-formation energies for the two step types, 41 and 60 meV, are 40-50% below experimental values drawn from STM images.(K. Arenhold et al., Surf. Sci. 424, 271(1999).) The discrepancy results from interpreting the images with a step-stiffness vs. kink-energy relation appropriate to (100) but not (111) surfaces. Good agreement is found when proper account of the trigonal symmetry of Pb(111) is taken in reinterpreting the step-stiffness data.
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Oral sucralfate in acute radiation oesophagitis
Energy Technology Data Exchange (ETDEWEB)
Sur, R.K. (Dept. of Radiotherapy, Postgraduate Inst. of Medical Education and Research, Chandigarh (India)); Kochhar, R. (Dept. of Gastroenterology, Postgraduate Inst. of Medical Education and Research, Chandigarh (India)); Singh, D.P. (Dept. of Radiotherapy, Postgraduate Inst. of Medical Education and Research, Chandigarh (India))
1994-01-01
Eighty patients with carcinoma in the middle third of oesophagus and with acute radiation oesophagitis following external beam and intracavitary radiotherapy were managed by two different schedules. Group 1 (n = 40) received an antacid containing sodium alginate whereas Group 2 (n = 40) were given a 10% sucralfate suspension during 4 weeks. In Group 2, 32 patients had significant relief of symptoms within 7 days of treatment and most ulcers had healed by 12 days of treatment as seen on endoscopy. Patients in Group 1, on the other hand, showed little improvement of symptoms and had persistent ulcers even after 4 weeks of therapy. We conclude that sucralfate is useful in the management of acute radiation oesophagitis. (orig.).
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Oral sucralfate in acute radiation oesophagitis
International Nuclear Information System (INIS)
Sur, R.K.; Kochhar, R.; Singh, D.P.
1994-01-01
Eighty patients with carcinoma in the middle third of oesophagus and with acute radiation oesophagitis following external beam and intracavitary radiotherapy were managed by two different schedules. Group 1 (n = 40) received an antacid containing sodium alginate whereas Group 2 (n = 40) were given a 10% sucralfate suspension during 4 weeks. In Group 2, 32 patients had significant relief of symptoms within 7 days of treatment and most ulcers had healed by 12 days of treatment as seen on endoscopy. Patients in Group 1, on the other hand, showed little improvement of symptoms and had persistent ulcers even after 4 weeks of therapy. We conclude that sucralfate is useful in the management of acute radiation oesophagitis. (orig.)
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Wang, Mingxing; Wu, Bo; Lu, Peijuan; Cloer, Caryn; Tucker, Jay D; Lu, Qilong
2012-01-01
We investigated a series of small-sized polyethylenimine (PEI, 0.8/1.2 k)-conjugated pluronic copolymers (PCMs) for their potential to enhance delivery of an antisense phosphorodiamidate morpholino oligomer (PMO) in vitro and in dystrophic mdx mice. PCM polymers containing pluronics of molecular weight (Mw) ranging 2–6 k, with hydrophilic-lipophilic balance (HLB) 7–23, significantly enhanced PMO-induced exon-skipping in a green fluorescent protein (GFP) reporter-based myoblast culture system....
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Ren, Yinshi; Han, Xianglong; Jing, Yan; Yuan, Baozhi; Ke, Huazhu; Liu, Min; Feng, Jian Q
2016-01-01
Unlike treatments for most rickets, the treatment using 1,25-(OH)2 vitamin D3 has little efficacy on patients with hypophosphatemic rickets, a set of rare genetic diseases. Thus, understanding the local cause for osteomalacia in hypophosphatemic rickets and developing an effective treatment to restore mineralization in this rare disease has been a longstanding goal in medicine. Here, we used Dmp1 knockout (KO) mice (whose mutations led to the same type of autosomal recessive hypophosphatemic rickets in humans) as the model in which the monoclonal antibody of sclerostin (Scl-Ab) was tested in two age groups for 8weeks: the prevention group (starting at age 4weeks) and the treatment group (starting at age 12weeks). Applications of Scl-Ab greatly improved the osteomalacia phenotype (>15%) and the biomechanical properties (3-point bending, ~60%) in the treated long-bone group. Our studies not only showed improvement of the osteomalacia in the alveolar bone, which has the highest bone metabolism rate, as well as the long bone phenotypes in treated mice. All these improvements attributed to the use of Scl-Ab are independent of the change in serum levels of phosphorus and FGF23, since Scl-Ab had little efficacy on those parameters. Finally, we propose a model to explain how Scl-Ab can improve the Dmp1 KO osteomalacia phenotype, in which the sclerostin level is already low. Copyright © 2016 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.
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DEFF Research Database (Denmark)
Schønning, Kristian; Bolmstedt, A; Novotny, J
1998-01-01
An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected...... immunogenic structures inaccessible on the envelope oligomer. The limited ability of recombinant gp120 vaccines to induce neutralizing antibodies against primary isolates may thus not exclusively reflect genetic variation....
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Simple synthesis, structure and ab initio study of 1,4-benzodiazepine-2,5-diones
Jadidi, Khosrow; Aryan, Reza; Mehrdad, Morteza; Lügger, Thomas; Ekkehardt Hahn, F.; Ng, Seik Weng
2004-04-01
A simple procedure for the synthesis of pyrido[2,1-c][1,4] benzodiazepine-6,12-dione ( 1) and 1,4-benzodiazepine-2,5-diones ( 2a- 2d), using microwave irradiation and/or conventional heating is reported. The configuration of 1 was determined by single-crystal X-ray diffraction. A detailed ab initio B3LYP/6-31G* calculation of structural parameters and substituent effects on ring inversion barriers (Δ G#) and also free energy differences (Δ G0) for benzodiazepines are reported.
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Detection of aniline oligomers on polyaniline-gold interface using resonance Raman scattering
Czech Academy of Sciences Publication Activity Database
Trchová, Miroslava; Morávková, Zuzana; Dybal, Jiří; Stejskal, Jaroslav
2014-01-01
Roč. 6, č. 2 (2014), s. 942-950 ISSN 1944-8244 R&D Projects: GA ČR GAP205/12/0911; GA ČR(CZ) GA13-00270S Institutional support: RVO:61389013 Keywords : polyaniline * aniline oligomers * Raman spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 6.723, year: 2014
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Structural Transitions of Solvent-Free Oligomer-Grafted Nanoparticles
Chremos, Alexandros
2011-09-01
Novel structural transitions of solvent-free oligomer-grafted nanoparticles are investigated by using molecular dynamics simulations of a coarse-grained bead-spring model. Variations in core size and grafting density lead to self-assembly of the nanoparticles into a variety of distinct structures. At the boundaries between different structures, the nanoparticle systems undergo thermoreversible transitions. This structural behavior, which has not been previously reported, deviates significantly from that of simple liquids. The reversible nature of these transitions in solvent-free conditions offers new ways to control self-assembly of nanoparticles at experimentally accessible conditions. © 2011 American Physical Society.
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Acute side effects after consumption of the new synthetic cannabinoids AB-CHMINACA and MDMB-CHMICA.
Hermanns-Clausen, Maren; Müller, Dieter; Kithinji, Josephine; Angerer, Verena; Franz, Florian; Eyer, Florian; Neurath, Hartmud; Liebetrau, Gesine; Auwärter, Volker
2018-06-01
In 2014, the "European Monitoring Centre for Drugs and Drug Addiction" (EMCDDA) reported on 30 novel synthetic cannabinoids (SCs). Among these were indole- and indazole-based valine derivatives with a cyclohexylmethyl side chain (e.g., AB-CHMINACA and MDMB-CHMICA), which represent a new class of SCs. A prospective observational study of patients treated in emergency departments (EDs) after the intake of SCs was conducted. Clinical and laboratory data were combined and reported to a poison control centre. Serum and/or urine samples of ED patients were analyzed using LC-MS/MS. Forty four patients (39 male, five female, 12-48 years) were included. AB-CHMINACA (MDMB-CHMICA) was identified in 20 (19) serum samples, and in 21 (25) urine samples, respectively. In 19 of the cases, more than one SC was present. Other psychoactive substances (mainly amfetamines) were identified in seven cases, but in five out of these in urine samples only. Based on the Poison Severity Score, severity of poisoning was minor (4), moderate (31) or severe (9). Most frequently reported neuropsychiatric symptoms were CNS-depression (n = 21, 61%), disorientation (n = 20, 45%), generalized seizures (n = 12, 27%), combativeness (n = 8, 18%) and extreme agitation (n = 7, 16%). Duration of symptoms lasting 24 hours or longer occurred in 15 cases (34%). The prevalence of certain neuropsychiatric symptoms was higher in our study than in former reports after the intake of SCs of the aminoalkylindole-type (first generation) SCs. In addition, severe poisoning and duration of symptoms were also higher. In this study, the valine derivative AB-CHMINACA and the tert-leucine derivative MDMB-CHMICA ("third generation of SCs") seem to be associated with more severe clinical toxicity than was previously reported in patients exposed to earlier generation SCs such as JWH-018. However, this observation needs to be confirmed with a larger cohort of patients with analytically confirmed abuse of
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Lower-power, high-linearity class-AB current-mode programmable gain amplifier
International Nuclear Information System (INIS)
Wu Yiqiang; Wang Zhigong; Wang Junliang; Ma Li; Xu Jian; Tang Lu
2014-01-01
A novel class-AB implementation of a current-mode programmable gain amplifier (CPGA) including a current-mode DC offset cancellation loop is presented. The proposed CPGA is based on a current amplifier and provides a current gain in a range of 40 dB with a 1 dB step. The CPGA is characterized by a wide range of current gain variation, a lower power dissipation, and a small chip size. The proposed circuit is fabricated using a 0.18 μm CMOS technology. The CPGA draws a current of less than 2.52 mA from a 1.8 V supply while occupying an active area of 0.099 μm 2 . The measured results show an overall gain variation from 10 to 50 dB with a gain error of less than 0.40 dB. The OP 1dB varies from 11.80 to 13.71 dBm, and the 3 dB bandwidth varies from 22.2 to 34.7 MHz over the whole gain range. (semiconductor integrated circuits)
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Sebollela, Adriano; Cline, Erika N; Popova, Izolda; Luo, Kevin; Sun, Xiaoxia; Ahn, Jay; Barcelos, Milena A; Bezerra, Vanessa N; Lyra E Silva, Natalia M; Patel, Jason; Pinheiro, Nathalia R; Qin, Lei A; Kamel, Josette M; Weng, Anthea; DiNunno, Nadia; Bebenek, Adrian M; Velasco, Pauline T; Viola, Kirsten L; Lacor, Pascale N; Ferreira, Sergio T; Klein, William L
2017-07-03
Brain accumulation of soluble oligomers of the amyloid-β peptide (AβOs) is increasingly considered a key early event in the pathogenesis of Alzheimer's disease (AD). A variety of AβO species have been identified, both in vitro and in vivo, ranging from dimers to 24mers and higher order oligomers. However, there is no consensus in the literature regarding which AβO species are most germane to AD pathogenesis. Antibodies capable of specifically recognizing defined subpopulations of AβOs would be a valuable asset in the identification, isolation, and characterization of AD-relevant AβO species. Here, we report the characterization of a human single chain antibody fragment (scFv) denoted NUsc1, one of a number of scFvs we have identified that stringently distinguish AβOs from both monomeric and fibrillar Aβ. NUsc1 readily detected AβOs previously bound to dendrites in cultured hippocampal neurons. In addition, NUsc1 blocked AβO binding and reduced AβO-induced neuronal oxidative stress and tau hyperphosphorylation in cultured neurons. NUsc1 further distinguished brain extracts from AD-transgenic mice from wild type (WT) mice, and detected endogenous AβOs in fixed AD brain tissue and AD brain extracts. Biochemical analyses indicated that NUsc1 targets a subpopulation of AβOs with apparent molecular mass greater than 50 kDa. Results indicate that NUsc1 targets a particular AβO species relevant to AD pathogenesis, and suggest that NUsc1 may constitute an effective tool for AD diagnostics and therapeutics. © 2017 International Society for Neurochemistry.
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International Nuclear Information System (INIS)
De Nardo, S.J.; De Nardo, G.L.; O'Grady, L.F.; Peng, J.S.; Macey, D.J.; Mills, S.L.; Caridiff, R.D.; Epstein, A.L.
1985-01-01
Studies of radiolabeled monoclonal antibodies are being performed by many investigators using a variety of molecular forms of the antibody. This study evaluates two I-123-labeled antibodies (Lym-1 IgG2a and B6.01 IgG1) and their I-123-labeled FAb and F(Ab')/sub 2/ for relative whole body distribution and kinetics, selected organ kinetics, and site of degradation. Evidence of immunocomplex formation, circulating antigen, and HAMA, were monitored by HPLC-TSK analysis and appropriate radioassays of the plasma. Each antibody and each I-123-labeled fragment has been evaluated in 5 patients. One patient had serial comparisons of the radiolabeled parent molecule, F(Ab')/sub 2/ (100μg and 5 mg) and FAb (100μg) of Lym-1. Blood clearance, urine excretion rate, and plasma and urine HPLC fractionation of the radioactive species were determined. Whole body clearance by total body scans and organ clearance were obtained by geometric mean of anterior and posterior areas of interest. The FAb and F(Ab')/sub 2/ fragments had similar blood pool recovery 5 minutes after the 5-minute injection. These were the same as blood levels when 5mg of intact I-123-labeled antibody was given. The second phase of the blood curves for F(Ab')/sub 2/ had a T1/2 of 35-40 hours and for FAb was 15-20 hours. Urine excretion varied, but agreed with total body loss from body scan information. The patient with serial studies had a 24-hour residual dose of 82% for FAb, 62% for 10μg for F(Ab')/sub 2/ and 61% for 5mg of F(Ab')/sub 2/. Renal uptake for all patients was higher and more persistent with both fragments than intact antibody, but hepatic uptake was less
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40 CFR 799.9130 - TSCA acute inhalation toxicity.
2010-07-01
... period. Chamber concentration may be measured using gravimetric or analytical methods as appropriate. If...) Conventional acute toxicity test—(1) Principle of the test method. Several groups of experimental animals are... practicable, monitored continuously or intermittently depending on the method of analysis, and recorded at...
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Energy Technology Data Exchange (ETDEWEB)
Magari, Masaki; Kanehiro, Yuichi; Todo, Kagefumi; Ikeda, Mika; Kanayama, Naoki, E-mail: nkanayama@cc.okayama-u.ac.jp; Ohmori, Hitoshi
2010-05-28
Chicken B cell line DT40 continuously accumulates mutations in the immunoglobulin variable region (IgV) gene by gene conversion and point mutation, both of which are mediated by activation-induced cytidine deaminase (AID), thereby producing an antibody (Ab) library that is useful for screening monoclonal Abs (mAbs) in vitro. We previously generated an engineered DT40 line named DT40-SW, whose AID expression can be reversibly switched on or off, and developed an in vitro Ab generation system using DT40-SW cells. To efficiently create an Ab library with sufficient diversity, higher hypermutation frequency is advantageous. To this end, we generated a novel cell line DT40-SW{Delta}C, which conditionally expresses a C-terminus-truncated AID mutant lacking the nuclear export signal. The transcription level of the mutant AID gene in DT40-SW{Delta}C cells was similar to that of the wild-type gene in DT40-SW cells. However, the protein level of the truncated AID mutant was less than that of the wild type. The mutant protein was enriched in the nuclei of DT40-SW{Delta}C cells, although the protein might be highly susceptible to degradation. In DT40-SW{Delta}C cells, both gene conversion and point mutation occurred in the IgV gene with over threefold higher frequency than in DT40-SW cells, suggesting that a lower level of the mutant AID protein was sufficient to increase mutation frequency. Thus, DT40-SW{Delta}C cells may be useful for constructing Ab libraries for efficient screening of mAbs in vitro.
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[Monoclonal antibodies in diagnosis of acute leukemias].
Krawczyńska, A; Robak, T
1996-01-01
Immunophenotyping has become an essential component for the study of acute myeloblastic (AML) and lymphoblastic (ALL) leukaemias. The recent development of highly specific monoclonal antibodies (Mc Ab) to differentiation antigens (CD) of haematopoetic cells have made it readily available to clinical laboratories in most major hospitals. Immunophenotyping complements standard morphology by providing information on lineage, stage of differentiation and clonality. In addition some of the flow cytometry findings have independent prognostic significance. Monoclonal antibodies useful in defining lineage (B-cell versus T-cell) and stages of differentiation of ALL. It can be also used in identifying characteristic feature of AML and aiding in lineage determination in acute leukaemias that are morphologically undifferentiated. Surface immunophenotyping is especially helpful for recognizing mixed lineage acute leukaemia and diagnosing certain rare entities such as erythroleukaemia (M6), acute megakaryocytic leukaemia (M7) and minimally differentiation acute myeloid leukaemia.
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Neutron Reflection Study of Surface Adsorption of Fc, Fab, and the Whole mAb.
Li, Zongyi; Li, Ruiheng; Smith, Charles; Pan, Fang; Campana, Mario; Webster, John R P; van der Walle, Christopher F; Uddin, Shahid; Bishop, Steve M; Narwal, Rojaramani; Warwicker, Jim; Lu, Jian Ren
2017-07-12
Characterizing the influence of fragment crystallization (Fc) and antigen-binding fragment (Fab) on monoclonal antibody (mAb) adsorption at the air/water interface is an important step to understanding liquid mAb drug product stability during manufacture, shipping, and storage. Here, neutron reflection is used to study the air/water adsorption of a mAb and its Fc and Fab fragments. By varying the isotopic contrast, the adsorbed amount, thickness, orientation, and immersion of the adsorbed layers could be determined unambiguously. While Fc adsorption reached saturation within the hour, its surface adsorbed amount showed little variation with bulk concentration. In contrast, Fab adsorption was slower and the adsorbed amount was concentration dependent. The much higher Fc adsorption, as compared to Fab, was linked to its lower surface charge. Time and concentration dependence of mAb adsorption was dominated by Fab behavior, although both Fab and Fc behaviors contributed to the amount of mAb adsorbed. Changing the pH from 5.5 to 8.8 did not much perturb the adsorbed amount of Fc, Fab, or mAb. However, a small decrease in adsorption was observed for the Fc over pH 8-8.8 and vice versa for the Fab and mAb, consistent with a dominant Fab behavior. As bulk concentration increased from 5 to 50 ppm, the thicknesses of the Fc layers were almost constant at 40 Å, while Fab and mAb layers increased from 45 to 50 Å. These results imply that the adsorbed mAb, Fc, and Fab all retained their globular structures and were oriented with their short axial lengths perpendicular to the interface.
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Dorhout, David L; Rice, Marlin E
2010-02-01
The effect of genetically modified corn (event MON810, YieldGard Corn Borer) expressing the Bacillus thuringiensis sp. kurstaki (Berliner) (Bt) endotoxin, Cry1Ab, on the survival of western bean cutworm, Striacosta albicosta (Smith), larvae was examined during intraguild competition studies with either European corn borer, Ostrinia nubilalis (Hübner), or corn earworm, Helicoverpa zea (Boddie), larvae. Competition scenarios were constructed by using either a laboratory or field competition arena containing one of five different diets and one of 13 different larval size-by-species scenarios. The survival of western bean cutworms competing with corn earworms in the laboratory arenas on either a meridic diet or isoline corn silk diet was significantly lower (P corn earworm on a Cry1Ab-MON810 corn silk diet was significant higher (P corn borers generally did not alter the outcomes observed in the western bean cutworm and corn earworm only two-way competitions. These data suggest that Cry1Ab-MON810 corn may confer a competitive advantage to western bean cutworm larvae during intraguild competition, particularly from corn earworms, and that western bean cutworms become equal competitors only when they are of equal or larger size and the diet is Cry1Ab-MON810 corn.
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Value of MRI and DTI as Biomarkers for Classifying Acute Spinal Cord Injury
2014-10-29
Datasets were checked for goodness of fit as part of the quality assurance process. Whole cord FA, MD, LD (λ1) and TD (λ23) were calculated for...discussion 1658. 10. Marino RJ, Ditunno JF,Jr, Donovan WH, Maynard F ,Jr. Neurologic recovery after traumatic spinal cord injury: Data from the model spinal...Jan;75(1):67-72. 17. Foo D, Subrahmanyan TS, Rossier AB. Post-traumatic acute anterior spinal cord syndrome. Paraplegia. 1981;19(4):201-5. 18
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PT-symmetry management in oligomer systems
International Nuclear Information System (INIS)
Horne, R L; Cuevas, J; Kevrekidis, P G; Whitaker, N; Abdullaev, F Kh; Frantzeskakis, D J
2013-01-01
We study the effects of management of the PT-symmetric part of the potential within the setting of Schrödinger dimer and trimer oligomer systems. This is done by rapidly modulating in time the gain/loss profile. This gives rise to a number of interesting properties of the system, which are explored at the level of an averaged equation approach. Remarkably, this rapid modulation provides for a controllable expansion of the region of exact PT-symmetry, depending on the strength and frequency of the imposed modulation. The resulting averaged models are analysed theoretically and their exact stationary solutions are translated into time-periodic solutions through the averaging reduction. These are, in turn, compared with the exact periodic solutions of the full non-autonomous PT-symmetry managed problem and very good agreement is found between the two. (paper)
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Ikigai, H; Nakae, T
1985-07-16
The membrane-damaging alpha-toxin aggregate of Staphylococcus aureus was characterized physicochemically. The aggregate weight of the toxin formed by various methods appeared to be 6 times higher than the molecular weight of the monomer as determined by the laser light scattering technique, suggesting the presence of a hexamer in the membrane. The aggregates fluoresced 20 to 50% more than the monomer at 336 nm. Circular dichroism measurements revealed that both the monomer and the oligomer showed essentially beta-sheet structure with the maximum ellipticity about -8,400 deg.cm2.dmol-1 at 215 nm. Circular dichroism spectrum of the oligomers showed ellipticity difference of -6,600, -44 and +84 deg.cm2.dmol-1, at 200, 250 and 280 nm, respectively, compared with the monomer. All these results suggest that the conformational change in the toxin molecule occurs concomitant with the transformation of the water-soluble monomer to the membrane-embedded hexamer.
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TIM-1 signaling in B cells regulates antibody production
International Nuclear Information System (INIS)
Ma, Juan; Usui, Yoshihiko; Takeda, Kazuyoshi; Harada, Norihiro; Yagita, Hideo; Okumura, Ko; Akiba, Hisaya
2011-01-01
Highlights: → TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. → Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. → TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3 + anti-CD28-stimulated CD4 + T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.
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TIM-1 signaling in B cells regulates antibody production
Energy Technology Data Exchange (ETDEWEB)
Ma, Juan [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Usui, Yoshihiko [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Department of Ophthalmology, Tokyo Medical University, 6-7-1 Nishi-shinjuku-ku, Tokyo 160-0023 (Japan); Takeda, Kazuyoshi [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Harada, Norihiro [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Department of Respiratory Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Research Institute for Diseases of Old Ages, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Yagita, Hideo; Okumura, Ko [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Akiba, Hisaya, E-mail: hisaya@juntendo.ac.jp [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan)
2011-03-11
Highlights: {yields} TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. {yields} Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. {yields} TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3{sup +} anti-CD28-stimulated CD4{sup +} T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.
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Netzel, Brian C; Grebe, Stefan K G; Carranza Leon, B Gisella; Castro, M Regina; Clark, Penelope M; Hoofnagle, Andrew N; Spencer, Carole A; Turcu, Adina F; Algeciras-Schimnich, Alicia
2015-08-01
Measurement of thyroglobulin (Tg) by mass spectrometry (Tg-MS) is emerging as a tool for accurate Tg quantification in patients with anti-Tg autoantibodies (TgAbs). The objective of the study was to perform analytical and clinical evaluations of two Tg-MS assays in comparison with immunometric Tg assays (Tg-IAs) and Tg RIAs (Tg-RIAs) in a cohort of thyroid cancer patients. A total of 589 samples from 495 patients, 243 TgAb-/252 TgAb+, were tested by Beckman, Roche, Siemens-Immulite, and Thermo-Brahms Tg and TgAb assays, two Tg-RIAs, and two Tg-MS assays. The frequency of TgAb+ was 58%, 41%, 27%, and 39% for Roche, Beckman, Siemens-Immulite, and Thermo-Brahms, respectively. In TgAb- samples, clinical sensitivities and specificities of 100% and 74%-100%, respectively, were observed across all assays. In TgAb+ samples, all Tg-IAs demonstrated assay-dependent Tg underestimation, ranging from 41% to 86%. In TgAb+ samples, the use of a common cutoff (0.5 ng/mL) for the Tg-MS, three Tg-IAs, and the USC-RIA improved the sensitivity for the Tg-MSs and Tg-RIAs when compared with the Tg-IAs. In up to 20% of TgAb+ cases, Tg-IAs failed to detect Tg that was detectable by Tg-MS. In Tg-RIAs false-high biases were observed in TgAb+ samples containing low Tg concentrations. Tg-IAs remain the method of choice for Tg quantitation in TgAb- patients. In TgAb+ patients with undetectable Tg by immunometric assay, the Tg-MS will detect Tg in up to 20% additional cases. The Tg-RIA will detect Tg in approximately 35% cases, but a significant proportion of these will be clinical false-positive results. The undetectable Tg-MS seen in approximately 40% of TgAb+ cases in patients with disease need further evaluation.
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Kawano, Hiroyuki; Yamamoto, Haruko; Miyata, Shigeki; Izumi, Manabu; Hirano, Teruyuki; Toratani, Naomi; Kakutani, Isami; Sheppard, Jo-Ann I; Warkentin, Theodore E; Kada, Akiko; Sato, Shoichiro; Okamoto, Sadahisa; Nagatsuka, Kazuyuki; Naritomi, Hiroaki; Toyoda, Kazunori; Uchino, Makoto; Minematsu, Kazuo
2011-01-01
Acute ischaemic stroke patients sometimes receive heparin for treatment and/or prophylaxis of thromboembolic complications. This study was designed to elucidate the incidence and clinical features of heparin-induced thrombocytopenia (HIT) in acute stroke patients treated with heparin. We conducted a prospective multicentre cohort study of 267 patients who were admitted to three stroke centres within 7 d after stroke onset. We examined clinical data until discharge and collected blood samples on days 1 and 14 of hospitalization to test anti-platelet factor 4/heparin antibodies (anti-PF4/H Abs) using an enzyme-linked immunosorbent assay (ELISA); platelet-activating antibodies were identified by serotonin-release assay (SRA). Patients with a 4Ts score ≥4 points, positive-ELISA, and positive-SRA were diagnosed as definite HIT. Heparin was administered to 172 patients (64·4%: heparin group). Anti-PF4/H Abs were detected by ELISA in 22 cases (12·8%) in the heparin group. Seven patients had 4Ts ≥ 4 points. Among them, three patients (1·7% overall) were also positive by both ELISA and SRA. National Institutes of Health Stroke Scale score on admission was high (range, 16–23) and in-hospital mortality was very high (66·7%) in definite HIT patients. In this study, the incidence of definite HIT in acute ischaemic stroke patients treated with heparin was 1·7% (95% confidence interval: 0·4–5·0). The clinical severity and outcome of definite HIT were unfavourable. PMID:21671895
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Bt Jute Expressing Fused δ-Endotoxin Cry1Ab/Ac for Resistance to Lepidopteran Pests
Directory of Open Access Journals (Sweden)
Shuvobrata Majumder
2018-01-01
Full Text Available Jute (Corchorus sp. is naturally occurring, biodegradable, lignocellulosic-long, silky, golden shiny fiber producing plant that has great demands globally. Paper and textile industries are interested in jute because of the easy availability, non-toxicity and high yield of cellulosic biomass produced per acre in cultivation. Jute is the major and most industrially used bast fiber-producing crop in the world and it needs protection from insect pest infestation that decreases its yield and quality. Single locus integration of the synthetically fused cry1Ab/Ac gene of Bacillus thuringiensis (Bt in Corchorus capsularis (JRC 321 by Agrobacterium tumefaciens-mediated shoot tip transformation provided 5 potent Bt jute lines BT1, BT2, BT4, BT7 and BT8. These lines consistently expressed the Cry1Ab/Ac endotoxin ranging from 0.16 to 0.35 ng/mg of leaf, in the following generations (analyzed upto T4. The effect of Cry1Ab/Ac endotoxin was studied against 3 major Lepidopteran pests of jute- semilooper (Anomis sabulifera Guenee, hairy caterpillar (Spilarctia obliqua Walker and indigo caterpillar (Spodoptera exigua Hubner by detached leaf and whole plant insect bioassay on greenhouse-grown transgenic plants. Results confirm that larvae feeding on transgenic plants had lower food consumption, body size, body weight and dry weight of excreta compared to non-transgenic controls. Insect mortality range among transgenic feeders was 66–100% for semilooper and hairy caterpillar and 87.50% for indigo caterpillar. Apart from insect resistance, the transgenic plants were at par with control plants in terms of agronomic parameters and fiber quality. Hence, these Bt jutes in the field would survive Lepidopteran pest infestation, minimize harmful pesticide usage and yield good quality fiber.
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Metaphyseal impaction fractures in acute lymphoblastic leukemia
Energy Technology Data Exchange (ETDEWEB)
Manson, D.; Cockshott, W.P.; Martin, R.F.
1989-01-01
Patients with acute lymphatic leukaemia frequently are osteoporotic. A small subset of these develop disabling metaphyseal transverse fractures, usually bilateral and in the lower limb. These impaction fractures have a characteristic appearance and develop in recently laid down bone. They may develop ab initio of during therapy, Magnesium deficiency is found in these patients.
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Metaphyseal impaction fractures in acute lymphoblastic leukemia
International Nuclear Information System (INIS)
Manson, D.; Cockshott, W.P.; Martin, R.F.
1989-01-01
Patients with acute lymphatic leukaemia frequently are osteoporotic. A small subset of these develop disabling metaphyseal transverse fractures, usually bilateral and in the lower limb. These impaction fractures have a characteristic appearance and develop in recently laid down bone. They may develop ab initio of during therapy, Magnesium deficiency is found in these patients. (orig.)
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Detection of aniline oligomers on polyaniline-gold interface using resonance Raman scattering.
Trchová, Miroslava; Morávková, Zuzana; Dybal, Jiří; Stejskal, Jaroslav
2014-01-22
In situ deposited conducting polyaniline films prepared by the oxidation of aniline with ammonium peroxydisulfate in aqueous media of various acidities on gold and silicon supports were characterized by Raman spectroscopy. Enhanced Raman bands were found in the spectra of polyaniline films produced in the solutions of weak acids or in water on gold surface. These bands were weak for the films prepared in solutions of a strong acid on a gold support. The same bands are present in the Raman spectra of the reaction intermediates deposited during aniline oxidation in water or aqueous solutions of weak or strong acids on silicon removed from the reaction mixture at the beginning of the reaction. Such films are formed by aniline oligomers adsorbed on the surface. They were detected on the polyaniline-gold interface using resonance Raman scattering on the final films deposited on gold. The surface resonance Raman spectroscopy of the monolayer of oligomers found in the bulk polyaniline film makes this method advantageous in surface science, with many applications in electrochemistry, catalysis, and biophysical, polymer, or analytical chemistry.
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International Nuclear Information System (INIS)
Ohta, Ayumi; Kobayashi, Osamu; Danielache, Sebastian O.; Nanbu, Shinkoh
2015-01-01
Highlights: • The photoisomerization between cyclohexadiene and hexatriene was simulated. • Nonadiabatic ab initio MD simulations were employed to elucidate the mechanism. • Each excitations to S_1 and S_2 were simulated using full-dimensional model. • Specific molecular motions at CoIns and molecular vibrations on S_1 PES were found. • The one-sided product branching ratio was obtained at the photoexcitation to S_2. - Abstract: The photoisomerization process between 1,3-cyclohexadiene (CHD) and 1,3,5-cis-hexatriene (HT) has been studied by nonadiabatic ab initio molecular dynamics based on trajectory surface-hopping approach with a full-dimensional reaction model. The quantum chemical calculations were treated at MS-MR-CASPT2 level for 8 electrons in 8 orbitals with the cc-pVDZ basis set. The Zhu–Nakamura formula was employed to evaluate nonadiabatic transition probabilities. S_1 and S_2 states were included in the photoisomerization dynamics. Lifetimes and CHD:HT branching ratios were computationally estimated on the basis of statistical analysis of multiple executed trajectories. The analysis of trajectories suggested that the nonadiabatic transitions at the S_0/S_1 and S_1/S_2 conical intersections (CoIn) are correlated to the Kekulé-type vibration and the C3–C4–C5 bending motion, respectively. The one-sided branching ratio was obtained by excitations to the S_2 state; 70:30. The critical branching process was found to be dominated by the location of CoIn in potential energy hypersurface of the excited state.
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Sanda, Takaomi; Lawton, Lee N.; Barrasa, M. Inmaculada; Fan, Zi Peng; Kohlhammer, Holger; Gutierrez, Alejandro; Ma, Wenxue; Tatarek, Jessica; Ahn, Yebin; Kelliher, Michelle A.; Jamieson, Catriona H.M.; Staudt, Louis M.; Young, Richard A.; Look, A. Thomas
2012-01-01
The oncogenic transcription factor TAL1/SCL is aberrantly expressed in over 40% of cases of human T-cell acute lymphoblastic leukemia (T-ALL), emphasizing its importance in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, LMO1/2, GATA3 and RUNX1. We show that TAL1 forms a positive interconnected auto-regulatory loop with GATA3 and RUNX1, and that the TAL1 complex directly activates the MY...
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Deficiency of the miR-29a/b-1 cluster leads to ataxic features and cerebellar alterations in mice
DEFF Research Database (Denmark)
Papadopoulou, Aikaterini S; Serneels, Lutgarde; Achsel, Tilmann
2015-01-01
miR-29 is expressed strongly in the brain and alterations in expression have been linked to several neurological disorders. To further explore the function of this miRNA in the brain, we generated miR-29a/b-1 knockout animals. Knockout mice develop a progressive disorder characterized by locomotor...... up-regulated in the cerebella of the miR-29a/b knockout mice. Dysregulation of KCNC3 expression may contribute to the ataxic phenotype....
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International Nuclear Information System (INIS)
Ma Caiyun; Jiang Li; Ge Gaoxia; Zhang Xiaojie
2005-01-01
Electrochemiluminescene immunoassay (ECLIA) and enzyme-linked immunosorbent (ELISA) were used to detect the different concentrations of serum HBsAb, in order to compare the results of ECLIA and ELISA. The result showed that intra-assay coefficient of variation of ECLIA was about 0.95% for high value, 1.13% for mean values and 2.63% for low value, while that of ELISA was about 5.76%, 12.8% and 15.9%, respectively. The interassay coefficient of ECLIA was about 4.03% for high values, 4.93% for mean values and 7.34% for low values, while that of ELISA was about 10.1%, 19.6% and 25.2%, respectively. The analytical sensitivity of ECLIA was about 4.0IU/L, while that of ELISA is about 19.0IU/L. Only in 3 samples, the results measured by ECLIA and ELISA were different (ECLIA: positive; ELISA: negative) among 165 samples. It is concluded that the met hod of ECLIA is more efficient than ELISA for detection of HBsAb in serum. (authors)
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Cloe, Adam L.; Orgel, Joseph P.R.O.; Sachleben, Joseph R.; Tycko, Robert; Meredith, Stephen C.
2012-01-01
The ΔE693 (Japanese) mutation of the β-amyloid precursor protein leads to production of ΔE22-Aβ peptides such as ΔE22-Aβ1–39. Despite reports that these peptides do not form fibrils, here we show that, on the contrary, the peptide forms fibrils essentially instantaneously. The fibrils are typical amyloid fibrils in all respects except that they cause only low levels of thioflavin T (ThT) fluorescence, which, however, develops with no lag phase. The fibrils bind ThT, but with a lower affinity and a smaller number of binding sites than wild-type (WT) Aβ1–40. Fluorescence depolarization confirms extremely rapid aggregation of ΔE22-Aβ1–39. Size exclusion chromatography (SEC) indicates very low concentrations of soluble monomer and oligomer, but only in the presence of some organic solvent, e.g., 2% (v/v) DMSO. The critical concentration is approximately 1 order of magnitude lower for ΔE22-Aβ1–39 than for WTAβ1–40. Several lines of evidence point to an altered structure for ΔE22-Aβ1–39 compared to that of WT Aβ1–40 fibrils. In addition to differences in ThT binding and fluorescence, PITHIRDS-CT solid-state nuclear magnetic resonance (NMR) measurements of ΔE22-Aβ1–39 are not compatible with the parallel in-register β-sheet generally observed for WT Aβ1–40 fibrils. X-ray fibril diffraction showed different D spacings: 4.7 and 10.4 Å for WT Aβ1–40 and 4.7 and 9.6 Å for ΔE22-Aβ1–39. Equimolar mixtures of ΔE22-Aβ1–39 and WT Aβ1–40 also produced fibrils extremely rapidly, and by the criteria of ThT fluorescence and electron microscopic appearance, they were the same as fibrils made from pure ΔE22-Aβ1–39. X-ray diffraction of fibrils formed from 1:1 molar mixtures of ΔE22-Aβ1–39 and WT Aβ1–40 showed the same D spacings as fibrils of the pure mutant peptide, not the wild-type peptide. These findings are consistent with extremely rapid nucleation by ΔE22-Aβ1–39, followed by fibril extension by WT Aβ1–40, and
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Ab initio pseudopotential theory
International Nuclear Information System (INIS)
Yin, M.T.; Cohen, M.L.
1982-01-01
The ab initio norm-conserving pseudopotential is generated from a reference atomic configuration in which the pseudoatomic eigenvalues and wave functions outside the core region agree with the corresponding ab initio all-electron results within the density-functional formalism. This paper explains why such pseudopotentials accurately reproduce the all-electron results in both atoms and in multiatomic systems. In particular, a theorem is derived to demonstrate the energy- and perturbation-independent properties of ab initio pseudopotentials
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Yuan, Xiang-Ai; Wen, Jin; Zheng, Dong; Ma, Jing
2018-04-01
This Review highlights the structure/property relationship underlying the morphology modulation through various factors towards the exploration of light-absorbing materials for efficient utilisation of solar power. Theoretical study using a combination of molecular dynamics imulations and the time-dependent density functional theory demonstrated that the planarity plays an important role in tuning spectral properties of oligomer aggregates. The aggregation-induced blue-shift in absorption spectra of oligothiophenes and the red-shift for oligofluorenols were rationalised in a unified way from the reduced (and increased) content of planar conformations in molecular aggregates. The planarity versus non-planarity of oligomers can be modulated by introduction of alkyl side chain or steric bulky substituents. The substitution with various groups in the ortho-position of azobenzene leads to the distorted backbone, breaking symmetry, and hence the red-shift in spectra, expanding the application in biological systems with visible light absorption. The donor-acceptor substituent groups in conjugated oligomers can increase the degree of planarity, electron delocalisation and polarisation, and charge separation, giving rise to the red-shift in spectra and enhancement in polarisability and charge mobility for device applications. The solvent dependent and pH-sensitive properties and intramolecular hydrogen bonds also caused the shift of absorption spectra with the appearance of planar conformers.
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Directory of Open Access Journals (Sweden)
Huiying Liu
2016-12-01
Full Text Available Background Acute lung injury and acute respiratory distress syndrome (ALI/ARDS is a severe clinical syndrome with mortality rate as high as 30–40%. There is no treatment yet to improve pulmonary endothelial barrier function in patients with severe pulmonary edema. Developing therapies to protect endothelial barrier integrity and stabilizing gas exchange is getting more and more attention. Sphingosine-1-phosphate (S1P is able to enhance the resistance of endothelial cell barrier. S1P at physiological concentrations plays an important role in maintaining endothelial barrier function. Proliferation, regeneration and anti-inflammatory activity that mesenchymal stem cells (MSCs exhibit make it possible to regulate the homeostatic control of S1P. Methods By building a pulmonary endothelial cell model of acute injury, we investigated the regulation of S1P receptors and sphingosine kinases expression by MSCs during the treatment of acute lung injury using RT-PCR, and investigated the HPAECs Micro-electronics impedance using Real Time Cellular Analysis. Results It was found that the down-regulation of TNF-α expression was more significant when MSC was used in combination with S1P. The combination effection mainly worked on S1PR2, S1PR3 and SphK2. The results show that when MSCs were used in combination with S1P, the selectivity of S1P receptors was increased and the homeostatic control of S1P concentration was improved through regulation of expression of S1P metabolic enzymes. Discussions The study found that, as a potential treatment, MSCs could work on multiple S1P related genes simultaneously. When it was used in combination with S1P, the expression regulation result of related genes was not simply the superposition of each other, but more significant outcome was obtained. This study establishes the experimental basis for further exploring the efficacy of improving endothelial barrier function in acute lung injury, using MSCs in combination with S1
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Liu, Huiying; Zhang, Zili; Li, Puyuan; Yuan, Xin; Zheng, Jing; Liu, Jinwen; Bai, Changqing; Niu, Wenkai
2016-01-01
Acute lung injury and acute respiratory distress syndrome (ALI/ARDS) is a severe clinical syndrome with mortality rate as high as 30-40%. There is no treatment yet to improve pulmonary endothelial barrier function in patients with severe pulmonary edema. Developing therapies to protect endothelial barrier integrity and stabilizing gas exchange is getting more and more attention. Sphingosine-1-phosphate (S1P) is able to enhance the resistance of endothelial cell barrier. S1P at physiological concentrations plays an important role in maintaining endothelial barrier function. Proliferation, regeneration and anti-inflammatory activity that mesenchymal stem cells (MSCs) exhibit make it possible to regulate the homeostatic control of S1P. By building a pulmonary endothelial cell model of acute injury, we investigated the regulation of S1P receptors and sphingosine kinases expression by MSCs during the treatment of acute lung injury using RT-PCR, and investigated the HPAECs Micro-electronics impedance using Real Time Cellular Analysis. It was found that the down-regulation of TNF- α expression was more significant when MSC was used in combination with S1P. The combination effection mainly worked on S1PR2, S1PR3 and SphK2. The results show that when MSCs were used in combination with S1P, the selectivity of S1P receptors was increased and the homeostatic control of S1P concentration was improved through regulation of expression of S1P metabolic enzymes. The study found that, as a potential treatment, MSCs could work on multiple S1P related genes simultaneously. When it was used in combination with S1P, the expression regulation result of related genes was not simply the superposition of each other, but more significant outcome was obtained. This study establishes the experimental basis for further exploring the efficacy of improving endothelial barrier function in acute lung injury, using MSCs in combination with S1P and their possible synergistic mechanism.
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ABS, MBS and CDO pricing comparisons : An empirical analysis
Vink, D.; Thibeault, A.
2008-01-01
The capital market in which asset-backed securities are issued and traded is composed of three main categories: ABS, MBS and CDOs. The authors examined a total of 3,466 loans (worth €548.51 billion) of which 1,102 (worth €163.90 billion) have been classified as ABS. MBS issues represent 1,782 issues
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van den Berg, T. K.; Hasbold, J.; Renardel de Lavalette, C.; Döpp, E. A.; Dijkstra, C. D.; Klaus, G. G.
1996-01-01
In this study we describe the tissue distribution of mouse CD40 using two monoclonal antibodies (mAb) against different epitopes of the molecule. In lymphoid tissues CD40 was expressed by B lymphocytes. Most B cells in typical B-cell compartments were CD40-positive, including germinal centre B
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Rakowski, Lesley A.; Lehotzky, Erica A.; Chiang, Mark Y.
2011-01-01
To improve the treatment strategies of T-cell acute lymphoblastic leukemia/lymphoma (T-ALL), further efforts are needed to identify therapeutic targets. Dysregulated expression of HOX-type transcription factors occurs in 30-40% of cases of T-ALL. TLX1/HOX11 is the prototypical HOX-type transcription factor. TLX1 may be an attractive therapeutic target because mice that are deficient in TLX1 are healthy. To test this possibility, we developed a conditional doxycycline-regulated mouse model of ...
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12 CFR Appendixes A-B to Part 41 - [Reserved
2010-01-01
... 12 Banks and Banking 1 2010-01-01 2010-01-01 false [Reserved] A Appendixes A-B to Part 41 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FAIR CREDIT REPORTING Appendixes A-B to Part 41 [Reserved] ...
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Electroless nickel plating on abs plastics from nickel chloride and nickel sulfate baths
International Nuclear Information System (INIS)
Inam-ul-haque; Ahmad, S.; Khan, A.
2005-01-01
Aqueous acid nickel chloride and alkaline nickel sulphate bath were studied for electroless nickel planting on acrylonitrile-butadiene-styrene (ABS) plastic. Before electroless nickel plating, specimens were etched, sensitized and activated. Effects of sodium hypophosphite and sodium citrate concentration on the electroless nickel plating thickness were discussed. Aqueous acid nickel chloride bath comprising, nickel chloride 10 g/L, sodium hypophosphite 40 g/L, sodium citrate 40g/L at pH 5.5, temperature 85 deg. C and density of 1 Be/ for thirty minutes gave best coating thickness in micrometer. It was found that acid nickel chloride bath had a greater stability, wide operating range and better coating thickness results than alkaline nickel sulphate bath. Acid nickel chloride bath gave better coating thickness than alkaline nickel sulfate bath
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Isomerism of OBe3F3+ cation: an ab initio study
International Nuclear Information System (INIS)
Klimenko, N.M.; Rykova, E.A.; MakKi, M.L.; Senchenya, I.N.
1999-01-01
Ab initio MP2/6-31G*/HF/6-31G*+ZPE(HF/6-31G*) calculations of the potential energy surface in the vicinity of stationary points and the pathways of intramolecular rearrangements between low-lying structures of the OBe 3 F 3 + cation detected in the mass spectra of μ 4 -Be 4 O(CF 3 COO) 6 were carried out. Ten stable isomers with di- and tricoordinate oxygen atoms were localized. The relative energies of six structures lie in the range 0-8 kcal mol -1 and those of the rest four structures lie in the range 20-40 kcal mol -1 . two most favorable isomers are a planar C 2 , isomer and a pyramidal C 3 isomer [ru
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Directory of Open Access Journals (Sweden)
Branco Luis M
2011-10-01
Full Text Available Abstract Background Lassa fever (LF is a devastating hemorrhagic viral disease that is endemic to West Africa and responsible for thousands of human deaths each year. Analysis of humoral immune responses (IgM and IgG by antibody-capture ELISA (Ab-capture ELISA and Lassa virus (LASV viremia by antigen-capture ELISA (Ag-capture ELISA in suspected patients admitted to the Kenema Government Hospital (KGH Lassa Fever Ward (LFW in Sierra Leone over the past five years is reshaping our understanding of acute LF. Results Analyses in LF survivors indicated that LASV-specific IgM persists for months to years after initial infection. Furthermore, exposure to LASV appeared to be more prevalent in historically non-endemic areas of West Africa with significant percentages of reportedly healthy donors IgM and IgG positive in LASV-specific Ab-capture ELISA. We found that LF patients who were Ag positive were more likely to die than suspected cases who were only IgM positive. Analysis of metabolic and immunological parameters in Ag positive LF patients revealed a strong correlation between survival and low levels of IL-6, -8, -10, CD40L, BUN, ALP, ALT, and AST. Despite presenting to the hospital with fever and in some instances other symptoms consistent with LF, the profiles of Ag negative IgM positive individuals were similar to those of normal donors and nonfatal (NF LF cases, suggesting that IgM status cannot necessarily be considered a diagnostic marker of acute LF in suspected cases living in endemic areas of West Africa. Conclusion Only LASV viremia assessed by Ag-capture immunoassay, nucleic acid detection or virus isolation should be used to diagnose acute LASV infection in West Africans. LASV-specific IgM serostatus cannot be considered a diagnostic marker of acute LF in suspected cases living in endemic areas of West Africa. By applying these criteria, we identified a dysregulated metabolic and pro-inflammatory response profile conferring a poor
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Branco, Luis M; Grove, Jessica N; Boisen, Matt L; Shaffer, Jeffrey G; Goba, Augustine; Fullah, Mohammed; Momoh, Mambu; Grant, Donald S; Garry, Robert F
2011-10-24
Lassa fever (LF) is a devastating hemorrhagic viral disease that is endemic to West Africa and responsible for thousands of human deaths each year. Analysis of humoral immune responses (IgM and IgG) by antibody-capture ELISA (Ab-capture ELISA) and Lassa virus (LASV) viremia by antigen-capture ELISA (Ag-capture ELISA) in suspected patients admitted to the Kenema Government Hospital (KGH) Lassa Fever Ward (LFW) in Sierra Leone over the past five years is reshaping our understanding of acute LF. Analyses in LF survivors indicated that LASV-specific IgM persists for months to years after initial infection. Furthermore, exposure to LASV appeared to be more prevalent in historically non-endemic areas of West Africa with significant percentages of reportedly healthy donors IgM and IgG positive in LASV-specific Ab-capture ELISA. We found that LF patients who were Ag positive were more likely to die than suspected cases who were only IgM positive. Analysis of metabolic and immunological parameters in Ag positive LF patients revealed a strong correlation between survival and low levels of IL-6, -8, -10, CD40L, BUN, ALP, ALT, and AST. Despite presenting to the hospital with fever and in some instances other symptoms consistent with LF, the profiles of Ag negative IgM positive individuals were similar to those of normal donors and nonfatal (NF) LF cases, suggesting that IgM status cannot necessarily be considered a diagnostic marker of acute LF in suspected cases living in endemic areas of West Africa. Only LASV viremia assessed by Ag-capture immunoassay, nucleic acid detection or virus isolation should be used to diagnose acute LASV infection in West Africans. LASV-specific IgM serostatus cannot be considered a diagnostic marker of acute LF in suspected cases living in endemic areas of West Africa. By applying these criteria, we identified a dysregulated metabolic and pro-inflammatory response profile conferring a poor prognosis in acute LF. In addition to suggesting that the
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Diffusivities and Viscosities of Poly(ethylene oxide) Oligomers †
Hong, Bingbing
2010-10-14
Diffusivities and viscosities of poly(ethylene oxide) (PEO) oligomer melts with 1 to 12 repeat units have been obtained from equilibrium molecular dynamics simulations using the TraPPE-UA force field. The simulations generated diffusion coefficients with high accuracy for all of the molar masses studied, but the statistical uncertainties in the viscosity calculations were significantly larger for longer chains. There is good agreement of the calculated viscosities and densities with available experimental data, and thus, the simulations can be used to bridge gaps in the data and for extrapolations with respect to chain length, temperature, and pressure. We explored the convergence characteristics of the Green-Kubo formulas for different chain lengths and propose minimal production times required for convergence of the transport properties. The chain-length dependence of the transport properties suggests that neither Rouse nor reptation models are applicable in the short-chain regime investigated. © 2010 American Chemical Society.
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International Nuclear Information System (INIS)
Desmazières, Bernard; Legros, Véronique; Giuliani, Alexandre; Buchmann, William
2014-01-01
Graphical abstract: Atmospheric pressure photoIonization mass spectra of synthetic oligomers were recorded in the negative mode by varying the photon energy using synchrotron radiation. Photon energy required for an efficient ionization of the polymer was correlated to ionization potential of the solvent (for example 9.4 eV for tetrahydrofuran). -- Highlights: •Atmospheric pressure photoionization was performed using synchrotron radiation. •Photoionization of oligomers in THF with 10% CH 2 Cl 2 produces intact [M + Cl] − ions. •The photon energy required corresponds to ionization potential of the solvent. •Polymer distributions depend on source parameters such T °C and applied voltages. •Liquid chromatography was coupled to MS using an APPI interface for polymer analysis. -- Abstract: Atmospheric pressure photoionization (APPI) followed by mass spectrometric detection was used to ionize a variety of polymers: polyethylene glycol, polymethyl methacrylate, polystyrene, and polysiloxane. In most cases, whatever the polymer or the solvent used (dichloromethane, tetrahydrofuran, hexane, acetone or toluene), only negative ion mode produced intact ions such as chlorinated adducts, with no or few fragmentations, in contrast to the positive ion mode that frequently led to important in-source fragmentations. In addition, it was shown that optimal detection of polymer distributions require a fine tuning of other source parameters such as temperature and ion transfer voltage. Series of mass spectra were recorded in the negative mode, in various solvents (dichloromethane, tetrahydrofuran, hexane, toluene, and acetone), by varying the photon energy from 8 eV up to 10.6 eV using synchrotron radiation. To these solvents, addition of a classical APPI dopant (toluene or acetone) was not necessary. Courtesy of the synchrotron radiation, it was demonstrated that the photon energy required for an efficient ionization of the polymer was correlated to the ionization energy
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Energy Technology Data Exchange (ETDEWEB)
Desmazières, Bernard [Global Bioenergies, 5 rue Henri Desbruyeres, 91030 Evry (France); Legros, Véronique [CNRS, UMR8587, Université d’Evry-Val-d’Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, F-91025 Evry (France); Giuliani, Alexandre [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, 91192 Gif-sur-Yvette (France); UAR1008, CEPIA, INRA, Rue de la Geraudiere, F-44316 Nantes (France); Buchmann, William, E-mail: william.buchmann@univ-evry.fr [CNRS, UMR8587, Université d’Evry-Val-d’Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, F-91025 Evry (France)
2014-01-15
Graphical abstract: Atmospheric pressure photoIonization mass spectra of synthetic oligomers were recorded in the negative mode by varying the photon energy using synchrotron radiation. Photon energy required for an efficient ionization of the polymer was correlated to ionization potential of the solvent (for example 9.4 eV for tetrahydrofuran). -- Highlights: •Atmospheric pressure photoionization was performed using synchrotron radiation. •Photoionization of oligomers in THF with 10% CH{sub 2}Cl{sub 2} produces intact [M + Cl]{sup −} ions. •The photon energy required corresponds to ionization potential of the solvent. •Polymer distributions depend on source parameters such T °C and applied voltages. •Liquid chromatography was coupled to MS using an APPI interface for polymer analysis. -- Abstract: Atmospheric pressure photoionization (APPI) followed by mass spectrometric detection was used to ionize a variety of polymers: polyethylene glycol, polymethyl methacrylate, polystyrene, and polysiloxane. In most cases, whatever the polymer or the solvent used (dichloromethane, tetrahydrofuran, hexane, acetone or toluene), only negative ion mode produced intact ions such as chlorinated adducts, with no or few fragmentations, in contrast to the positive ion mode that frequently led to important in-source fragmentations. In addition, it was shown that optimal detection of polymer distributions require a fine tuning of other source parameters such as temperature and ion transfer voltage. Series of mass spectra were recorded in the negative mode, in various solvents (dichloromethane, tetrahydrofuran, hexane, toluene, and acetone), by varying the photon energy from 8 eV up to 10.6 eV using synchrotron radiation. To these solvents, addition of a classical APPI dopant (toluene or acetone) was not necessary. Courtesy of the synchrotron radiation, it was demonstrated that the photon energy required for an efficient ionization of the polymer was correlated to the
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Energy Technology Data Exchange (ETDEWEB)
Valldor, Petra; Miethling-Graff, Rona; Dockhorn, Susanne; Martens, Rainer; Tebbe, Christoph C. [Federal Research Institute for Rural Areas, Forestry and Fisheries, Braunschweig (Germany). Thuenen Institute (vTI) for Biodiversity
2012-10-15
Insecticidal Cry proteins naturally produced by Bacillus thuringiensis are a major recombinant trait expressed by genetically modified crops. They are released into the soil during and after cropping. The objective of this study was to produce {sup 14}C-labeled Cry1Ab proteins for soil metabolic studies in scope of their environmental risk assessment. Cry1Ab was synthesized as a protoxin by Escherichia coli HB101 pMP in 200-mL liquid batch culture fermentations and purified from inclusion bodies after trypsin digestion. For cultivation, U-{sup 14}C-glycerol was the main carbon source. Inclusion bodies were smaller and Cry1Ab yield was lower when the initial amount of total organic carbon in the cultivation broth was below 6.4 mg C L{sup -1}. Concentrations of 12.6 g {sup 14}C-labeled glycerol L{sup -1} (1 % v/v) resulted in the production of 17.1 mg {sup 14}C-Cry1Ab L{sup -1} cultivation medium. {sup 14}C mass balances showed that approx. 50 % of the label was lost by respiration and 20 % remained in the growth media, while the residual activity was associated with biomass. Depending on the production batch, 0.01 to 0.05 % of the total {sup 14}C originated from Cry1Ab. In the presence of 2.04 MBq {sup 14}C-labeled carbon sources, a specific activity of up to 268 Bq mg{sup -1} {sup 14}C-Cry1Ab was obtained. A more than threefold higher specific activity was achieved with 4.63 MBq and an extended cultivation period of 144 h. This study demonstrates that {sup 14}C-labeled Cry1Ab can be obtained from batch fermentations with E. coli in the presence of a simple {sup 14}C-labeled carbon source. It also provides a general strategy to produce {sup 14}C-labeled proteins useful for soil metabolic studies. (orig.)
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Czech Academy of Sciences Publication Activity Database
Plachý, T.; Sedlačík, M.; Pavlínek, V.; Trchová, Miroslava; Morávková, Zuzana; Stejskal, Jaroslav
2014-01-01
Roč. 256, 15 November (2014), s. 398-406 ISSN 1385-8947 R&D Projects: GA ČR GAP205/12/0911; GA ČR(CZ) GA13-08944S Institutional support: RVO:61389013 Keywords : aniline * aniline oligomers * carbonization Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.321, year: 2014
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Rashid al-Din. Shu’ab-i panjganah. 2. The Mongols and Turks (1 »
Directory of Open Access Journals (Sweden)
Chulpan I. Khamidova
2016-09-01
Full Text Available Research objectives and materials: The “Shu’ab-i panjganah” is a Persian manuscript of Rashid al-Din’s works – the medieval historian who lived in Persia and worked at the Ilkhanid court at the end of the 13th – beginning of the 14th centuries. The manuscript is a largely genealogical work written on the basis of a more comprehensive historical work of Rashid al-Din – “Jami al-Tawarikh”. “Shu’ab-i panjganah” contains genealogies of the prophets of Abrahamic religions, the rulers of the Arab Caliphate until the conquest of Baghdad by the Mongols, the Chinese dynasties and rulers of the Holy Roman Empire, as well as a list of the Popes. The greatest interest for this study is spurred by the fifth part, dedicated to the Chinggisids. The article presents a part of the translation of the 2nd chapter of the manuscript. This part contains a genealogical tree of Chinggis Khan (from his ancestor Dubun bayan, but without his descendants. The results of translation and analyses of the text of the manuscript could serve to various purposes: study of Rashid al-Din’s heritage, Great Horde history, genealogical history of Chinggis Khan and his descendants. The translation of the manuscript has never been published neither partly nor fully. Research results and novelty: The genealogy of Chinggis Khan’s ancestors contained in “Shu’ab-i panjganah” mainly repeats the information from “Jami al-Tawarikh”, although additional data is also available. Comparison of “Shu’ab-i panjganah” with brief genealogical tables in “Jami al-Tawarikh” shows that, on the one hand, “Shu’ab-i panjganah” is an addition to “Jami al-Tawarikh”, and on the other hand, the tables in “Jami al-Tawarikh” is a kind of rough version of the genealogical trees contained in “Shu’ab-i panjganah”.
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Revealing strategies of quorum sensing in Azospirillum brasilense strains Ab-V5 and Ab-V6.
Fukami, Josiane; Abrantes, Julia Laura Fernandes; Del Cerro, Pablo; Nogueira, Marco Antonio; Ollero, Francisco Javier; Megías, Manuel; Hungria, Mariangela
2018-01-01
Azospirillum brasilense is an important plant-growth promoting bacterium (PGPB) that requires several critical steps for root colonization, including biofilm and exopolysaccharide (EPS) synthesis and cell motility. In several bacteria these mechanisms are mediated by quorum sensing (QS) systems that regulate the expression of specific genes mediated by the autoinducers N-acyl-homoserine lactones (AHLs). We investigated QS mechanisms in strains Ab-V5 and Ab-V6 of A. brasilense, which are broadly used in commercial inoculants in Brazil. Neither of these strains carries a luxI gene, but there are several luxR solos that might perceive AHL molecules. By adding external AHLs we verified that biofilm and EPS production and cell motility (swimming and swarming) were regulated via QS in Ab-V5, but not in Ab-V6. Differences were observed not only between strains, but also in the specificity of LuxR-type receptors to AHL molecules. However, Ab-V6 was outstanding in indole acetic acid (IAA) synthesis and this molecule might mimic AHL signals. We also applied the quorum quenching (QQ) strategy, obtaining transconjugants of Ab-V5 and Ab-V6 carrying a plasmid with acyl-homoserine lactonase. When maize (Zea mays L.) was inoculated with the wild-type and transconjugant strains, plant growth was decreased with the transconjugant of Ab-V5-confirming the importance of an AHL-mediated QS system-but did not affect plant growth promotion by Ab-V6.
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Directory of Open Access Journals (Sweden)
Sean D. O’Shea
2008-11-01
Full Text Available Extensive evidence supports an important role for soluble oligomers of the amyloid β-protein (Aβ in Alzheimer’s Disease pathogenesis. In the present study we combined intracerebroventricular (icv injections with brain microdialysis technology in the fully conscious rat to assess the effects of icv administered SDS-stable low-n Aβ oligomers (principally dimers and trimers on excitatory and inhibitory amino acid transmission in the ipsilateral dorsal hippocampus. Microdialysis was employed to assess the effect of icv administration of Aβ monomers and Aβ oligomers on dialysate glutamate, aspartate and GABA levels in the dorsal hippocampus. Administration of Aβ oligomers was associated with a +183% increase (p<0.0001 vs. Aβ monomer-injected control in dorsal hippocampal glutamate levels which was still increasing at the end of the experiment (260 min, whereas aspartate and GABA levels were unaffected throughout. These findings demonstrate that icv administration and microdialysis technology can be successfully combined in the awake rat and suggests that altered dorsal hippocampal glutamate transmission may be a useful target for pharmacological intervention in Alzheimer’s Disease.
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MODIFIED ALVARADO SCORING IN ACUTE APPENDICITIS
Directory of Open Access Journals (Sweden)
Varadarajan Sujath
2016-12-01
Full Text Available BACKGROUND Acute appendicitis is one of the most common surgical emergencies with a lifetime presentation of approximately 1 in 7. Its incidence is 1.5-1.9/1000 in males and females. Surgery for acute appendicitis is based on history, clinical examination and laboratory investigations (e.g. WBC count. Imaging techniques add very little to the efficacy in the diagnosis of appendix. A negative appendicectomy rate of 20-40% has been reported in literature. A difficulty in diagnosis is experienced in very young patients and females of reproductive age. The diagnostic accuracy in assessing acute appendicitis has not improved in spite of rapid advances in management. MATERIALS AND METHODS The modified Alvarado score was applied and assessed for its accuracy in preparation diagnosis of acute appendicitis in 50 patients. The aim of our study is to understand the various presentations of acute appendicitis including the age and gender incidence and the application of the modified Alvarado scoring system in our hospital setup and assessment of the efficacy of the score. RESULTS Our study shows that most involved age group is 3 rd decade with male preponderance. On application of Alvarado score, nausea and vomiting present in 50% and anorexia in 30%, leucocytosis was found in 75% of cases. Sensitivity and specificity of our study were 65% and 40% respectively with positive predictive value of 85% and negative predictive value of 15%. CONCLUSION This study showed that clinical scoring like the Alvarado score can be a cheap and quick tool to apply in emergency departments to rule out acute appendicitis. The implementation of modified Alvarado score is simple and cost effective.
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Boyanton, Bobby L; Almradi, Amro; Mehta, Tejal; Robinson-Dunn, Barbara
2014-04-01
The Directigen EZ Flu A+B rapid influenza diagnostic test, as compared to real-time reverse transcriptase polymerase chain reaction, demonstrated suboptimal performance to detect pandemic influenza A/H1N1 2009. Age- and viral load-stratified test sensitivity ranged from 33.3 to 84.6% and 0 to 100%, respectively. © 2013.
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ABS, MBS and CDO compared : An empirical analysis
Vink, D.; Thibeault, A.
2008-01-01
The capital market in which the asset-backed securities are issued and traded is composed of three main categories: ABS, MBS and CDOs. We were able to examine a total number of 3,951 loans (worth €730.25 billion) of which 1,129 (worth €208.94 billion) have been classified as ABS. MBS issues
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Undoing Gender Through Legislation and Schooling: the Case of AB 537 and AB 394 IN California, USA
Knotts, Greg
2009-11-01
This article investigates California laws AB 537: The Student Safety and Violence Prevention Act of 2000, and the recently enacted AB 394: Safe Place to Learn Act. Both demand that gender identity and sexual orientation be added to the lexicon of anti-harassment protection in public education. However, despite these progressive measures, schools have an unconscious acceptance of heteronormativity and gendered norms, which undermines both the spirit and language of these laws. This paper examines how California schools can both change standard practices and realise the transformative social change that laws like AB 537 and AB 394 can instigate. I assert that the systemic implementation of these laws, through the adoption, enforcement and evaluation of existing AB 537 Task Force Recommendations, is necessary for their success. My second assertion is that AB 537 and AB 394 have the potential to change and reconstitute gender-based and heteronormative standards at school sites.
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Assessment of the impact of Cry1Ab expression on insects dwelling on the maize plants
Czech Academy of Sciences Publication Activity Database
Habuštová, Oxana; Doležal, Petr; Hussein, H. M.; Spitzer, Lukáš; Turanli, F.; Růžička, Vlastimil; Sehnal, František
2007-01-01
Roč. 37, supplement 1 (2007), s. 50-51 ISSN 1738-2297. [International Congress of Insect Biotechnology and Industry. 19.08.2007-24.08.2007, Daegu] R&D Projects: GA AV ČR KJB6007304 Institutional research plan: CEZ:AV0Z50070508 Keywords : GM crops * Cry1Ab endotoxin * European corn borer Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection
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Modeling Disordered Materials with a High Throughput ab-initio Approach
2015-11-13
Modeling Disordered Materials with a High Throughput ab - initio Approach Kesong Yang,1 Corey Oses,2 and Stefano Curtarolo3, 4 1Department of...J. Furthmüller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54, 11169–11186 (1996
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Design, synthesis, and characterization of biomimetic oligomers
DEFF Research Database (Denmark)
Laursen, Jonas Striegler
a helical arrangement found by DFT calculations. The designed oligomer indeed proved the existence of a ß-peptoid helical conformation by X-ray. Further studies of these compounds indicated a structured display in solution. These helices thus definitively show that the ß-peptoids should be considered......Peptides and proteins made from the 20 canonical amino acids are responsible for many processes necessary for organisms to function. Beside their composition, proteins obtain their activity and unique selectivity through an ability to display functionalities accurately in the three......, for their ability to mimic the structural elements seen in proteins. Two prominent peptidomimetics are ß-peptides and a-peptoids (N-alkylglycines), which have been shown to fold into helical and sheet-like arrangements. To expand the chemical space available for mimicking protein structure their features have been...
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Gonioscopic ab interno laser sclerostomy. A pilot study in glaucoma patients.
Latina, M A; Melamed, S; March, W F; Kass, M A; Kolker, A E
1992-11-01
The purpose of this study is to evaluate the safety and efficacy of gonioscopic ab interno laser sclerostomy (GLS) in patients with glaucoma. The technique of GLS involves iontophoresis of methylene blue dye (1%) at the limbus to focally dye the sclera and to provide subsequent delivery of 10-microsecond pulsed laser energy to the dyed area through a goniolens. The laser emits at 660 nm, a wavelength that is maximally absorbed by the methylene blue dye. Patients were evaluated for fistula formation, intraocular pressure (IOP) reduction, and adverse sequelae. Thirty-eight treatments were performed in 35 eyes. Successful complete sclerostomies were achieved in 21 eyes (55%), which was associated with an acute mean reduction in IOP of 23 mmHg. Mean preoperative IOP for all patients was 35 mmHg, and 1 hour after treatment it was reduced to 18.5 mmHg. In 4 of the 38 treatments, there was no acute IOP reduction, and these eyes were judged as failures. The mean follow-up time was 8.2 months with a maximum follow-up of 15 months. By 9 months, 50% of patients had an IOP of 22 mmHg or lower. The number of antiglaucoma medications decreased from 3.1 to 1.7 for all eyes over the 15-month follow-up period. Hyphemas (13%) were the only major complication, and these resolved spontaneously. In only one case did the IOP increase after the procedure. The results of this trial indicate that GLS is technically feasible, and preliminary results of IOP control are promising.
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Directory of Open Access Journals (Sweden)
Carol L Ladner-Keay
Full Text Available The formation of β-sheet rich prion oligomers and fibrils from native prion protein (PrP is thought to be a key step in the development of prion diseases. Many methods are available to convert recombinant prion protein into β-sheet rich fibrils using various chemical denaturants (urea, SDS, GdnHCl, high temperature, phospholipids, or mildly acidic conditions (pH 4. Many of these methods also require shaking or another form of agitation to complete the conversion process. We have identified that shaking alone causes the conversion of recombinant PrP to β-sheet rich oligomers and fibrils at near physiological pH (pH 5.5 to pH 6.2 and temperature. This conversion does not require any denaturant, detergent, or any other chemical cofactor. Interestingly, this conversion does not occur when the water-air interface is eliminated in the shaken sample. We have analyzed shaking-induced conversion using circular dichroism, resolution enhanced native acidic gel electrophoresis (RENAGE, electron microscopy, Fourier transform infrared spectroscopy, thioflavin T fluorescence and proteinase K resistance. Our results show that shaking causes the formation of β-sheet rich oligomers with a population distribution ranging from octamers to dodecamers and that further shaking causes a transition to β-sheet fibrils. In addition, we show that shaking-induced conversion occurs for a wide range of full-length and truncated constructs of mouse, hamster and cervid prion proteins. We propose that this method of conversion provides a robust, reproducible and easily accessible model for scrapie-like amyloid formation, allowing the generation of milligram quantities of physiologically stable β-sheet rich oligomers and fibrils. These results may also have interesting implications regarding our understanding of prion conversion and propagation both within the brain and via techniques such as protein misfolding cyclic amplification (PMCA and quaking induced conversion (QuIC.
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International Nuclear Information System (INIS)
Jain, R.; Sawhney, S.; Rizvi, S.G.
2008-01-01
Aim: To prove the hypothesis that acute bone infarcts in sickle cell disease are caused by sequestration of red blood cells (RBCs) in bone marrow, and to evaluate the unenhanced T1 fat-saturated (fs) sequence in the differentiation of acute bone infarction from acute osteomyelitis in patients with sickle-cell disease. Materials and methods: Two studies were undertaken: an experimental study using in-vitro packed red blood cells and normal volunteers, and a retrospective clinical study of 86 magnetic resonance imaging (MRI) studies. For the experimental study containers of packed RBCs were placed between the knees of four healthy volunteers with a saline bag under the containers as an additional control, and were scanned with the pre-contrast T1-fs sequence. Signal intensity (SI) ratios were obtained for packed RBCs:skeletal muscle and packed RBCs:saline. For the clinical study, the SIs of normal bone marrow, packed RBCs, bone and/or soft-tissue lesions, and normal skeletal muscle of 74 patients (86 MRI studies) were measured using unenhanced, T1 fat-saturated MRI. The ratios of the above SIs to normal skeletal muscle were calculated and subjected to statistical analysis. Results: Fifty-one of 86 MRI studies were included in the final analysis. The ratios of SIs for normal bone marrow, packed red cells, bone infarction, acute osteomyelitis, and soft-tissue lesions associated with bone infarct, compared with normal skeletal muscle were (mean ± SD) 0.9 ± 0.2, 2.1 ± 0.7, 1.7 ± 0.5, 1.0 ± 0.3, and 2.2 ± 0.7, respectively. The difference in the ratio of SIs of bone infarcts and osteomyelitis was significant (p = 0.003). The final diagnoses were bone infarction (n = 50), acute osteomyelitis (n = 1), and co-existent bone infarction and osteomyelitis (n = 2). Seven patients who had suspected osteomyelitis underwent image-guided aspiration. Conclusion: Acute bone infarcts in sickle cell disease are caused by sequestration of red blood cells in the bone marrow. The
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A theoretical-spectroscopy, ab initio-based study of the electronic ground state of 121SbH3
International Nuclear Information System (INIS)
Yurchenko, Sergei N.; Carvajal, Miguel; Yachmenev, Andrey; Thiel, Walter; Jensen, Per
2010-01-01
For the stibine isotopologue 121 SbH 3 , we report improved theoretical calculations of the vibrational energies below 8000 cm -1 and simulations of the rovibrational spectrum in the 0-8000 cm -1 region. The calculations are based on a refined ab initio potential energy surface and on a new dipole moment surface obtained at the coupled cluster CCSD(T) level. The theoretical results are compared with the available experimental data in order to validate the ab initio surfaces and the TROVE computational method [Yurchenko SN, Thiel W, Jensen P. J Mol Spectrosc 2007;245:126-40] for calculating rovibrational energies and simulating rovibrational spectra of arbitrary molecules in isolated electronic states. A number of predicted vibrational energies of 121 SbH 3 are provided in order to stimulate new experimental investigations of stibine. The local-mode character of the vibrations in stibine is demonstrated through an analysis of the results in terms of local-mode theory.
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Zhang, Guichuan; Zhou, Cheng; Sun, Chen; Jia, Xiaoe; Xu, Baomin; Ying, Lei; Huang, Fei; Cao, Yong
2017-07-01
Variations in the open-circuit voltage (V oc ) of ternary organic solar cells are systematically investigated. The initial study of these devices consists of two electron-donating oligomers, S2 (two units) and S7 (seven units), and the electron-accepting [6,6]-phenyl C71 butyric acid methyl ester (PC 71 BM) and reveals that the V oc is continuously tunable due to the changing energy of the charge transfer state (E ct ) of the active layers. Further investigation suggests that V oc is also continuously tunable upon change in E ct in a ternary blend system that consists of S2 and its corresponding polymer (P11):PC 71 BM. It is interesting to note that higher power conversion efficiencies can be obtained for both S2:S7:PC 71 BM and S2:P11:PC 71 BM ternary systems compared with their binary systems, which can be ascribed to an improved V oc due to the higher E ct and an improved fill factor due to the improved film morphology upon the incorporation of S2. These findings provide a new guideline for the future design of conjugated polymers for achieving higher performance of ternary organic solar cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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A direct ab initio molecular dynamics (MD) study on the benzophenone-water 1 : 1 complex.
Tachikawa, Hiroto; Iyama, Tetsuji; Kato, Kohichi
2009-07-28
Direct ab initio molecular dynamics (MD) method has been applied to a benzophenone-water 1 : 1 complex Bp(H(2)O) and free benzophenone (Bp) to elucidate the effects of zero-point energy (ZPE) vibration and temperature on the absorption spectra of Bp(H(2)O). The n-pi transition of free-Bp (S(1) state) was blue-shifted by the interaction with a water molecule, whereas three pi-pi transitions (S(2), S(3) and S(4)) were red-shifted. The effects of the ZPE vibration and temperature of Bp(H(2)O) increased the intensity of the n-pi transition of Bp(H(2)O) and caused broadening of the pi-pi transitions. In case of the temperature effect, the intensity of n-pi transition increases with increasing temperature. The electronic states of Bp(H(2)O) were discussed on the basis of the theoretical results.
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Intestinal tuberculosis presenting as acute abdomen
International Nuclear Information System (INIS)
Khan, M.A.; Majeed, F.A.; Ahmed, M.; Khan, M.N.
2012-01-01
Objectives: To study the outcome of intestinal tuberculosis presenting as acute abdomen. Study design: Descriptive Study. Place and Duration: Bolan Medical Complex Hospital (BMC) Quetta and Combined Military Hospital (CMH) Quetta from Nov 2003 to Nov 2005 from Bolan Medical Complex and from Nov 2005 to Nov 2006 in CMH Quetta. Material and Method: Thirty seven patients of acute abdomen presenting with intestinal obstruction were admitted; 28 from emergency department and 9 from out patient department. Twenty seven patients were from BMC and 10 from CMH Quetta. Patients were diagnosed as having abdominal tuberculosis on the basis of operative findings and histopathological reports. Results: Out of 37 patients presenting with acute abdomen due to intestinal obstruction, 54% were male and 46% were female with M: F ratio of 1: 1.2. Age of the patient ranged from 20 to 50 years, with maximum frequency between 30 to 40 years. Abdominal pain was the commonest presenting feature in all patients followed by constipation in 81.1% patients. Peritonism was seen in 27% patients. Different operative procedures performed were adhesionolysis 65.8%, segmental resection 7.9%, right hemicolectomy 10.5%, stricturoplasty 7.9% and ileostomy 1.3%. Mesenteric lymph node biopsy 40.8%. Conclusion: Intestinal tuberculosis is still a very important surgical problem in our country presenting as acute abdomen. A suspicion must always be kept during laparotomy and adequate tissue histopathology should supplement the diagnosis. (author)
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Jalali, Sushil K; Yadavalli, Lalitha; Ojha, Rakshit; Kumar, Pradyumn; Sulaikhabeevi, Suby B; Sharma, Reema; Nair, Rupa; Kadanur, Ravi C; Kamath, Subray P; Komarlingam, Mohan S
2015-08-01
Among the major pests of maize in India are two stem borers, Chilo partellus (Swinhoe) and Sesamia inferens (Walker), and an earworm, Helicoverpa armigera (Hübner). As a pest control strategy, transgenic Bacillus thuringiensis (Bt) maize hybrids are undergoing regulatory trials in India. We have determined the sensitivity of the target lepidopterans to the insecticidal Bt proteins expressed in Bt maize, as this determines product efficacy and the resistance management strategy to be adopted. Maize hybrids with event MON89034 express two insecticidal Bt proteins, Cry1A.105 and Cry2Ab2. Sensitivity profiles of 53 populations of C. partellus, 21 populations of S. inferens and 21 populations of H. armigera, collected between 2008 and 2013 from maize-growing areas in India, to Cry1A.105 and Cry2Ab2 proteins were generated through dose-response assays. Cry1A.105 protein was the most effective to neonates of C. partellus (mean MIC90 range 0.30-1.0 µg mL(-1) ) and H. armigera (mean MIC90 range 0.71-8.22 µg mL(-1) ), whereas Cry2Ab2 (mean MIC90 range 0.65-1.70 µg mL(-1) ) was the most effective to S. inferens. Populations of C. partellus, S. inferens and H. armigera were susceptible to the Bt proteins Cry1A.105 and Cry2Ab2. The Bt sensitivity data will serve as precommercialisation benchmarks for resistance monitoring purposes. © 2014 Society of Chemical Industry.
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Directory of Open Access Journals (Sweden)
Marco eMainardi
2014-01-01
Full Text Available Brain aging is characterized by global changes which are thought to underlie age-related cognitive decline. These include variations in brain activity and the progressive increase in the concentration of soluble amyloid-β (Aβ oligomers, directly impairing synaptic function and plasticity even in the absence of any neurodegenerative disorder. Considering the high social impact of the decline in brain performance associated to aging, there is an urgent need to better understand how it can be prevented or contrasted. Lifestyle components, such as social interaction, motor exercise and cognitive activity, are thought to modulate brain physiology and its susceptibility to age-related pathologies. However, the precise functional and molecular factors that respond to environmental stimuli and might mediate their protective action again pathological aging still need to be clearly identified. To address this issue, we exploited environmental enrichment (EE, a reliable model for studying the effect of experience on the brain based on the enhancement of cognitive, social and motor experience, in aged wild-type mice. We analyzed the functional consequences of EE on aged brain physiology by performing in vivo local field potential (LFP recordings with chronic implants. In addition, we also investigated changes induced by EE on molecular markers of neural plasticity and on the levels of soluble Aβ oligomers. We report that EE induced profound changes in the activity of the primary visual and auditory cortices and in their functional interaction. At the molecular level, EE enhanced plasticity by an upward shift of the cortical excitation/inhibition balance. In addition, EE reduced brain Aβ oligomers and increased synthesis of the Aβ-degrading enzyme neprilysin. Our findings strengthen the potential of EE procedures as a non-invasive paradigm for counteracting brain aging processes.
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Detrusor Acontractility after Acute Spinal Cord Injury-Myth or Reality?
Bywater, Mirjam; Tornic, Jure; Mehnert, Ulrich; Kessler, Thomas M
2018-01-17
We assessed urodynamic parameters within the first 40 days after spinal cord injury to investigate whether the detrusor is acontractile during the acute phase of spinal cord injury. We performed a prospective cohort study in 54 patients with neurogenic lower urinary tract dysfunction due to acute spinal cord injury who underwent urodynamic investigation within the first 40 days after injury at a single university spinal cord injury center. Urodynamic investigation revealed an acontractile detrusor in only 20 of the 54 patients (37%) but unfavorable urodynamic parameters in 34 (63%). We found detrusor overactivity in 32 patients, detrusor-sphincter dyssynergia in 25, maximum storage detrusor pressure greater than 40 cm H 2 O in 17, vesicoureteral reflux in 3 and low bladder compliance (less than 20 ml/cm H 2 O) in 1. More than 1 unfavorable urodynamic parameter per patient was possible. In contrast to the common notion of an acontractile detrusor during acute spinal cord injury, almost two-thirds of our patients showed unfavorable urodynamic parameters within the first 40 days after spinal cord injury. Considering that early treatment of neurogenic lower urinary tract dysfunction in patients with acute spinal cord injury might improve the long-term urological outcome, urodynamic investigation should be performed timely to optimize patient tailored therapy. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Considine Robert V
2011-01-01
Full Text Available Abstract Background Nut consumption may reduce the risk of developing type 2 diabetes. The aim of the current study was to measure the acute and second-meal effects of morning almond consumption and determine the contribution of different nut fractions. Methods Fourteen impaired glucose tolerant (IGT adults participated in a randomized, 5-arm, crossover design study where whole almonds (WA, almond butter (AB, defatted almond flour (AF, almond oil (AO or no almonds (vehicle - V were incorporated into a 75 g available carbohydrate-matched breakfast meal. Postprandial concentrations of blood glucose, insulin, non-esterified free fatty acids (NEFA, glucagon-like peptide-1 (GLP-1 and appetitive sensations were assessed after treatment breakfasts and a standard lunch. Results WA significantly attenuated second-meal and daylong blood glucose incremental area under the curve (AUCI and provided the greatest daylong feeling of fullness. AB and AO decreased blood glucose AUCI in the morning period and daylong blood glucose AUCI was attenuated with AO. WA and AO elicited a greater second-meal insulin response, particularly in the early postprandial phase, and concurrently suppressed the second-meal NEFA response. GLP-1 concentrations did not vary significantly between treatments. Conclusions Inclusion of almonds in the breakfast meal decreased blood glucose concentrations and increased satiety both acutely and after a second-meal in adults with IGT. The lipid component of almonds is likely responsible for the immediate post-ingestive response, although it cannot explain the differential second-meal response to AB versus WA and AO.
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Directory of Open Access Journals (Sweden)
Y. Wen
2017-12-01
Full Text Available Highly soluble fluorinated ethynyl-terminated imide (FETI oligomers were prepared via a conventional one-step method in m-cresol, using 4, 4′-(hexafluoroisopropylidene diphthalic anhydride and 2, 2′-bis(trifluoromethyl benzidine as the monomers, and ethynylphthalic anhydride as the end-capper; then interpenetrating polymer networks (IPN were formulated from FETI oligomers and bisphenol A dicyanate ester (BADCy through a solvent-free procedure, and their thermal, mechanical, and dielectric properties were fully characterized. The curing mechanism was studied by model reactions using nitrogen nuclear magnetic resonance. As evidenced by differential scanning calorimetry analysis and rheological measurements, the FETI/BADCy blends exhibited lower curing temperature and shorter gelation time in comparison with pure BADCy due to the catalytic effects of ethynyl and residue amic acid groups. The properties of IPNs were fully compared with those of polycyanurate, and the results revealed that the incorporation of FETI into cyanate ester resins could significantly improve the toughness, glass transition temperatures, mechanical and dielectric properties of the resultant IPNs.
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International Nuclear Information System (INIS)
Yemul, Shrishailam; Leon, J.A.; Pozniakoff, Ted; Esser, P.D.; Estabrook, Alison; Met-Path Inc., Teterboro, NJ
1993-01-01
Radioimmunoimaging characteristics of a new monoclonal antibody EBA-1 and its F(ab') 2 fragments utilizing nu/nu mice bearing human breast carcinoma xenografts are described. 111 In-DPTA conjugates of EBA-1 localized with tumor/blood ratios of 0.99 ± 0.10 (P 2 radioconjugates at 48 h. These results suggest that EBA-1 and its F(ab') 2 might be useful reagents in radioimmunoimaging and radioimmunotherapy. (author)
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Directory of Open Access Journals (Sweden)
Xiaolin He
Full Text Available BACKGROUND: Interaction between the coagulation and inflammation systems plays an important role in the development of acute respiratory distress syndrome (ARDS. Anti-coagulation is an attractive option for ARDS treatment, and this has promoted development of new antibodies. However, preclinical trials for these antibodies are often limited by the high cost and availability of non-human primates. In the present study, we developed a novel alternative method to test the role of a humanized anti-tissue factor mAb in acute lung injury with transgenic mice. METHODOLOGY/PRINCIPAL FINDINGS: Human tissue factor knock-in (hTF-KI transgenic mice and a novel humanized anti-human tissue factor mAb (anti-hTF mAb, CNTO859 were developed. The hTF-KI mice showed a normal and functional expression of hTF. The anti-hTF mAb specifically blocked the pro-coagulation activity of brain extracts from the hTF-KI mice and human, but not from wild type mice. An extrapulmonary ARDS model was used by intestinal ischemia-reperfusion. Significant lung tissue damage in hTF-KI mice was observed after 2 h reperfusion. Administration of CNTO859 (5 mg/kg, i.v. attenuated the severity of lung tissue injury, decreased the total cell counts and protein concentration in bronchoalveolar lavage fluid, and reduced Evans blue leakage. In addition, the treatment significantly reduced alveolar fibrin deposition, and decreased tissue factor and plasminogen activator inhibitor-1 activity in the serum. This treatment also down-regulated cytokine expression and reduced cell death in the lung. CONCLUSIONS: This novel anti-hTF antibody showed beneficial effects on intestinal ischemia-reperfusion induced acute lung injury, which merits further investigation for clinical usage. In addition, the use of knock-in transgenic mice to test the efficacy of antibodies against human-specific proteins is a novel strategy for preclinical studies.
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Amyloid β oligomers in Alzheimer's disease pathogenesis, treatment, and diagnosis.
Viola, Kirsten L; Klein, William L
2015-02-01
Protein aggregation is common to dozens of diseases including prionoses, diabetes, Parkinson's and Alzheimer's. Over the past 15 years, there has been a paradigm shift in understanding the structural basis for these proteinopathies. Precedent for this shift has come from investigation of soluble Aβ oligomers (AβOs), toxins now widely regarded as instigating neuron damage leading to Alzheimer's dementia. Toxic AβOs accumulate in AD brain and constitute long-lived alternatives to the disease-defining Aβ fibrils deposited in amyloid plaques. Key experiments using fibril-free AβO solutions demonstrated that while Aβ is essential for memory loss, the fibrillar Aβ in amyloid deposits is not the agent. The AD-like cellular pathologies induced by AβOs suggest their impact provides a unifying mechanism for AD pathogenesis, explaining why early stage disease is specific for memory and accounting for major facets of AD neuropathology. Alternative ideas for triggering mechanisms are being actively investigated. Some research favors insertion of AβOs into membrane, while other evidence supports ligand-like accumulation at particular synapses. Over a dozen candidate toxin receptors have been proposed. AβO binding triggers a redistribution of critical synaptic proteins and induces hyperactivity in metabotropic and ionotropic glutamate receptors. This leads to Ca(2+) overload and instigates major facets of AD neuropathology, including tau hyperphosphorylation, insulin resistance, oxidative stress, and synapse loss. Because different species of AβOs have been identified, a remaining question is which oligomer is the major pathogenic culprit. The possibility has been raised that more than one species plays a role. Despite some key unknowns, the clinical relevance of AβOs has been established, and new studies are beginning to point to co-morbidities such as diabetes and hypercholesterolemia as etiological factors. Because pathogenic AβOs appear early in the disease, they
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Directory of Open Access Journals (Sweden)
Tingting Fu
2016-01-01
Full Text Available Purpose. Although active targeting of drugs using a magnetic-targeted drug delivery system (MTDS with superparamagnetic iron oxide nanoparticles (SPIONs is a very effective treatment approach for tumors and other illnesses, successful results of drug-resistant temporal lobe epilepsy (TLE are unprecedented. A hallmark in the neuropathology of TLE is brain inflammation, in particular the activation of interleukin-1β (IL-1β induced by activated glial cells, which has been considered a new mechanistic target for treatment. The purpose of this study was to determine the feasibility of the functionalized SPIONs with anti-IL-1β monoclonal antibody (mAb attached to render MRI diagnoses and simultaneously provide targeted therapy with the neutralization of IL-1β overexpressed in epileptogenic zone of an acute rat model of TLE. Experimental Design. The anti-IL-1β mAb-SPIONs were studied in vivo versus plain SPIONs and saline. Lithium-chloride pilocarpine-induced TLE models (n=60 were followed by Western blot, Perl’s iron staining, Nissl staining, and immunofluorescent double-label staining after MRI examination. Results. The magnetic anti-IL-1β mAb-SPION administered intravenously, which crossed the BBB and was concentrated in the astrocytes and neurons in epileptogenic tissues, rendered these tissues visible on MRI and simultaneously delivered anti-IL-1β mAb to the epileptogenic focus. Conclusions. Our study provides the first evidence that the novel approach enhanced accumulation and the therapeutic effect of anti-IL-1β mAb by MTDS using SPIONs.
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Directory of Open Access Journals (Sweden)
Sara Monteiro
Full Text Available There are literally hundreds of polypeptides described in the literature which exhibit fungicide activity. Tens of them have had attempted protection by patent applications but none, as far as we are aware, have found application under real agricultural conditions. The reasons behind may be multiple where the sensitivity to the Sun UV radiation can come in first place. Here we describe a multifunctional glyco-oligomer with 210 kDa which is mainly composed by a 20 kDa polypeptide termed Blad that has been previously shown to be a stable intermediary product of β-conglutin catabolism. This oligomer accumulates exclusively in the cotyledons of Lupinus species, between days 4 and 12 after the onset of germination. Blad-oligomer reveals a plethora of biochemical properties, like lectin and catalytic activities, which are not unusual per si, but are remarkable when found to coexist in the same protein molecule. With this vast range of chemical characteristics, antifungal activity arises almost as a natural consequence. The biological significance and potential technological applications of Blad-oligomer as a plant fungicide to agriculture, its uniqueness stems from being of polypeptidic in nature, and with efficacies which are either equal or greater than the top fungicides currently in the market are addressed.
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Yang, Fei; Chen, Mao; Gowda, Anilkumar; Kerns, David L; Huang, Fangneng
2018-04-01
The sugarcane borer, Diatraea saccharalis (F.), is a major maize borer pest and a target of transgenic maize expressing Bacillus thuringiensis (Bt) proteins in South America and the mid-southern region of the United States. Evolution of resistance in target pest populations is a great threat to the long-term efficacy of Bt crops. In this study, we compared the genetic basis of resistance to Cry1Ab protein in 3 resistant colonies of sugarcane borer established from field populations in Louisiana, USA. Responses of larvae to the Cry1Ab protein for the parental and 10 other cross colonies were assayed in a diet-incorporated bioassay. All 3 resistant colonies were highly resistant to the Cry1Ab protein with a resistance ratio of >555.6 fold. No maternal effect or sex linkage was evident for the resistance in the 3 colonies; and the resistance was functionally nonrecessive at the Cry1Ab concentrations of ≤ 3.16 μg/g, but it became recessive at ≥10 μg/g. In an interstrain complementation test for allelism, the F 1 progeny from crosses between any 2 of the 3 resistant colonies exhibited the similar resistance levels as their parental colonies, indicating that the 3 colonies most likely shared a locus of Cry1Ab resistance. Results generated from this study should provide useful information in developing effective strategies for managing Bt resistance in the insect. © 2016 Institute of Zoology, Chinese Academy of Sciences.
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Anti-CD25 mAb administration prevents spontaneous liver transplant tolerance.
Li, W; Carper, K; Liang, Y; Zheng, X X; Kuhr, C S; Reyes, J D; Perkins, D L; Thomson, A W; Perkins, J D
2006-12-01
Liver allografts are accepted spontaneously in all mouse strain combinations without immunosuppressive therapy. The mechanisms underlying this phenomenon remain largely undefined. In this study, we examined the effect of CD4+ CD25+ T regulatory cells (Treg) on the induction of mouse liver transplant tolerance. Orthotopic liver transplantation was performed from B10 (H2b) to C3H (H2k) mice. Depleting rat anti-mouse CD25 mAb (PC61) was given to the donors or recipients (250 microg/d IP) pretransplant or to the recipients postoperatively. At day 5 posttransplantation, both effector T cells (mainly CD8) and CD4+ CD25+ Treg were increased in the liver allografts and host spleens compared to naïve mice. Anti-CD25 mAb administration, either pretransplantation or posttransplantation, reduced the ratio of CD4+ CD25+ Treg to the CD3 T cells of liver grafts and recipient spleens and induced liver allograft acute rejection compared to IgG treatment. Anti-CD25 mAb administration elevated anti-donor T-cell proliferative responses and CTL and NK activities of graft infiltrates and host splenocytes; reduced CTLA4, Foxp3, and IDO mRNA levels; increased IL-10 and IFN-gamma; and decreased IL-4 mRNA levels in the livers or host spleens. The number of apoptotic T cells was reduced significantly in the liver grafts and treated host spleens. Therefore, anti-CD25 mAb administration changed the balance of CD4+ CD25+ Treg to activated T cells of liver graft recipients, preventing liver transplant tolerance. This was associated with enhanced anti-donor immune reactivity, downregulated Treg gene expression, and reduced T cell apoptosis in the grafts and host spleens.
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Saleh, Mahdi; Spence, John Nathan; Nayak, Sanjeev; Pearce, Gillian; Tennuci, Christopher; Roffe, Christine
2012-01-01
There are a limited number of studies comparing the Aperio mechanical thrombectomy device to other stent-based devices. In this paper, we compared the Aperio thrombectomy device to the Solitaire AB, FR and Revive devices in a model of the middle cerebral artery (MCA) within a modified pulsatile flow system. Thrombi made of lamb's blood were placed into a pulsatile flow system perfused with Hartmann's solution at 80 bpm with a mean pressure of 90 mm Hg. 30 experiments were run with each device. Recanalization rates were similar for all three devices (90% with the Solitaire AB, FR, 80% with the Revive, and 90% with the Aperio). The mean number of attempts to retrieve the thrombus was also similar for all three devices (1.7 with the Solitaire AB, FR, 2.1 with the Revive, 1.6 with the Aperio). Clot fragmentation and embolization rates revealed no statistical significance but there was a trend towards lower embolization rates with the Aperio (23% compared to 40% with the Solitaire AB, FR and 47% with the Revive). The Aperio was the fastest to recanalize the MCA (mean of 66 seconds compared to 186 seconds for the Solitaire AB, FR and 169 seconds for the Revive). In this in vitro setting, the Aperio device seems to be an efficacious and safe device when compared to other similar clinically used mechanical thrombectomy devices. Larger clinical trials are warranted.
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Directory of Open Access Journals (Sweden)
A. K. Porunova
2014-01-01
Full Text Available It is shown that developed method of titrating AB0 antibodies allows defi ning the titer of the investigational antibodies more precisely on 1–3 dilution of serum compared to the prototype method (titration method of antibodiesin saline medium on the plane. It is more obvious as it excludes hardly interpretable results due to the possibility of conducting visual assessment of agglutination reaction in the gel card thick column and requires less time foranalysis. The results can be saved for comparison with the results of further research. That is not possible under prototype titration method. Aim: our aim is to create a laboratory technique that can accurately, reliably and clearly produce titration of AB0 system antibodies, including in patients with low initial concentration of agglutinins in the blood; a technique more economical in terms of spending serum and that takes less time.Materials and methods: those modes were empirically chosen which allow titration of AB0 system agglutinins using gel technology based micro typing; to titer group antibodies 1640 serum assays of recipients in AB0-incompatibletransplantation were analyzed.The result of the use of specially developed method in organ transplantation from incompatible blood donors consists in enhancing accuracy, sensitivity of natural, complete and incomplete AB0 system immune antibodies titration, in its clarity, using of blood micro-doses for earlier detection of sensitizing of the patient, which is especially important in Pediatrics. Conclusion: the developed procedure of AB0-antibodies’ titration using modern gel technology makes possible a more precise monitoring of the titer of antibodies that is necessary to predict the graft rejection risk, to select the Protocol of preoperative preparation and postoperative management of patients, to assess the effectiveness of therapy in patients for whom it is diffi cult to fi nd a compatible blood type donor, and for whom today AB
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Expression of enzymes in yeast for lignocellulose derived oligomer CBP
McBride, John E.; Wiswall, Erin; Shikhare, Indraneel; Xu, Haowen; Thorngren, Naomi; Hau, Heidi H.; Stonehouse, Emily
2017-08-29
The present invention provides a multi-component enzyme system that hydrolyzes hemicellulose oligomers from hardwood which can be expressed, for example, in yeast such as Saccharomyces cerevisiae. In some embodiments, this invention provides for the engineering of a series of biocatalysts combining the expression and secretion of components of this enzymatic system with robust, rapid xylose utilization, and ethanol fermentation under industrially relevant process conditions for consolidated bioprocessing. In some embodiments, the invention utilizes co-cultures of strains that can achieve significantly improved performance due to the incorporation of additional enzymes in the fermentation system.
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Directory of Open Access Journals (Sweden)
Sergio Ordúz
2000-02-01
Full Text Available
Bacillus thuringiensis produce d1 endotoxinas que requieren activación proteolítica para ser activas. La activación de la toxina citolítica de 28 kDa (Cyt1Ab1 de B. thuringiensis subesp. Medellín con tripsina, quimotripsina y extractos intestinales de larvas del mosquito Culex quinquefasciatus fue analizada. La toxina Cyt1Ab1 de B. thuringiensis subsp. medellin fue procesada por todas las proteasa evaluadas a fragmentes entre 23 y 25 kDa, mientras que el procesamiento de la toxina Cyt1Aa1 produjo fragmentos entre 22.5 y 24.5 kDa. La toxina Cyt1Ab1 fue procesada preferencialmente in vitro en un pH de 12, produciendo un fragmento de 25 kDa cuando se trató con extractos intestinales de larvas de mosquito, y resultados similares se obtuvieron cuando la toxina fue activada in vivo por larvas de C. quinquefasciatus. La toxina solubilizada y los fragmentos resistentes a la acción de las proteasas generados en los experimentos in vitro, demostraron actividad hemolítica, pero no mosquitocida. La secuencia amino terminal del fragmento tratado con extractos intestinales de C. quinquefasciatus indica que el sitio de corte está localizado entre Lys31 y Asp32, generando una proteína con secuencia amino Terminal de DDPNEKNNHNS; mientras que la toxina tratada con tripsina mostró un sitio de corte entre Leu29 y Arg30, y la tratada con
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Swenson, Dana L; Warfield, Kelly L; Warren, Travis K; Lovejoy, Candace; Hassinger, Jed N; Ruthel, Gordon; Blouch, Robert E; Moulton, Hong M; Weller, Dwight D; Iversen, Patrick L; Bavari, Sina
2009-05-01
Phosphorodiamidate morpholino oligomers (PMOs) are uncharged nucleic acid-like molecules designed to inactivate the expression of specific genes via the antisense-based steric hindrance of mRNA translation. PMOs have been successful at knocking out viral gene expression and replication in the case of acute viral infections in animal models and have been well tolerated in human clinical trials. We propose that antisense PMOs represent a promising class of therapeutic agents that may be useful for combating filoviral infections. We have previously shown that mice treated with a PMO whose sequence is complementary to a region spanning the start codon of VP24 mRNA were protected against lethal Ebola virus challenge. In the present study, we report on the abilities of two additional VP24-specific PMOs to reduce the cell-free translation of a VP24 reporter, to inhibit the in vitro replication of Ebola virus, and to protect mice against lethal challenge when the PMOs are delivered prior to infection. Additionally, structure-activity relationship evaluations were conducted to assess the enhancement of antiviral efficacy associated with PMO chemical modifications that included conjugation with peptides of various lengths and compositions, positioning of conjugated peptides to either the 5' or the 3' terminus, and the conferring of charge modifications by the addition of piperazine moieties. Conjugation with arginine-rich peptides greatly enhanced the antiviral efficacy of VP24-specific PMOs in infected cells and mice during lethal Ebola virus challenge.
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Xu, Peng-Xin; Wang, Shao-Wei; Yu, Xiao-Lin; Su, Ya-Jing; Wang, Teng; Zhou, Wei-Wei; Zhang, He; Wang, Yu-Jiong; Liu, Rui-Tian
2014-05-01
Alzheimer's disease (AD) is a progressive, neurodegenerative disease characterized by extracellular β-amyloid (Aβ) plaques and intracellular neurofibrillary tangles in the brain. Aβ aggregation is closely associated with neurotoxicity, oxidative stress, and neuronal inflammation. The soluble Aβ oligomers are believed to be the most neurotoxic form among all forms of Aβ aggregates. We have previously reported a polyphenol compound rutin that could inhibit Aβ aggregation and cytotoxicity, attenuate oxidative stress, and decrease the production of nitric oxide and proinflammatory cytokines in vitro. In the current study, we investigated the effect of rutin on APPswe/PS1dE9 transgenic mice. Results demonstrated that orally administered rutin significantly attenuated memory deficits in AD transgenic mice, decreased oligomeric Aβ level, increased super oxide dismutase (SOD) activity and glutathione (GSH)/glutathione disulfide (GSSG) ratio, reduced GSSG and malondialdehyde (MDA) levels, downregulated microgliosis and astrocytosis, and decreased interleukin (IL)-1β and IL-6 levels in the brain. These results indicated that rutin is a promising agent for AD treatment because of its antioxidant, anti-inflammatory, and reducing Aβ oligomer activities. Copyright © 2014 Elsevier B.V. All rights reserved.
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International Nuclear Information System (INIS)
Charkin, O.P.; Klimenko, N.M.; MakKi, M.L.
2000-01-01
The nonempiric calculations of the potential energies surfaces in the vicinity of the key structures of the loose dimer molecules of the (LiNO) 2 , (LiPO) 2 , (LiNS) 2 and (LiPS) 2 lithium salts with 24 valence electrons are accomplished within the frames of the MP2/6-31G * //HF/6-31g * + ZPE(HF/6-31G * and MP4SDTQ/6-31G * //MP2/6-31G * + ZPE(MP2/6-31G * ) approximation. The equilibrium geometrical parameters, relative energies and isomer decay energies, frequencies and IR-intensities of normal vibrations are determined. The geometrical deformations and shifts of vibrational frequencies of the cis- and trans-dianions under the effect of cations by different ways of their coordination as well as tendencies of the molecular properties behaviour in various series of dimers (LiAB) 2 are analyzed. The results obtained are compared with the data of previous calculations of the LiAB salts monomeric molecules, the Li 2 AB + ions with 12 valence electrons and the (LiAB) 2 dimers with 20 valence electrons [ru
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Hypothermia-Related Acute Pancreatitis
Directory of Open Access Journals (Sweden)
Kyawzaw Lin
2018-05-01
Full Text Available Acute pancreatitis (AP is an inflammatory disease presenting from mild localized inflammation to severe infected necrotic pancreatic tissue. In the literature, there are a few cases of hypothermia-induced AP. However, the association between hypothermia and AP is still a myth. Generally, mortality from acute pancreatitis is nearly 3–6%. Here, we present a 40-year-old chronic alcoholic female who presented with acute pancreatitis induced by transient hypothermia. A 40-year-old chronic alcoholic female was hypothermic at 81°F on arrival which was improved to 91.7°F with warming blanket and then around 97°F in 8 h. Laboratory tests including complete blood count, lipid panel, and comprehensive metabolic panels were within the normal limit. Serum alcohol level was 0.01, amylase 498, lipase 1,200, ammonia 26, serum carboxyhemoglobin level 2.4, and β-HCG was negative. The entire sepsis workup was negative. During rewarming period, she had one episode of witnessed generalized tonic-clonic seizure. It was followed by transient hypotension. Fluid challenge was successful with 2 L of normal saline. Sonogram (abdomen showed fatty liver and trace ascites. CAT scan (abdomen and pelvis showed evidence of acute pancreatitis without necrosis, peripancreatic abscess, pancreatic mass, or radiopaque gallstones. The patient was managed medically and later discharged from the hospital on the 4th day as she tolerated a normal low-fat diet. In our patient, transient hypothermia from chronic alcohol abuse and her social circumstances might predispose to microcirculatory disturbance resulting in acute pancreatitis. Early and aggressive fluid resuscitation prevents complications.
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Di Fiore, Riccardo; Drago-Ferrante, Rosa; Pentimalli, Francesca; Di Marzo, Domenico; Forte, Iris Maria; D'Anneo, Antonella; Carlisi, Daniela; De Blasio, Anna; Giuliano, Michela; Tesoriere, Giovanni; Giordano, Antonio; Vento, Renza
2014-11-01
Osteosarcoma (OS) is the most common type of bone cancer, with a peak incidence in the early childhood. Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. MicroRNAs (miRNAs) have been implicated in the maintenance of the CSC phenotype, thus, identification of CSC-related miRNAs would provide information for a better understanding of CSCs. Downregulation of miRNA-29 family members (miR-29a/b/c; miR‑29s) was observed in human OS, however, little is known about the functions of miR-29s in human OS CSCs. Previously, during the characterization of 3AB-OS cells, a CSC line selected from human OS MG63 cells, we showed a potent downregulation of miR-29b. In this study, after stable transfection of 3AB-OS cells with miR-29b-1, we investigated the role of miR-29b-1 in regulating cell proliferation, sarcosphere-forming ability, clonogenic growth, chemosensitivity, migration and invasive ability of 3AB-OS cells, in vitro. We found that, miR-29b-1 overexpression consistently reduced both, 3AB-OS CSCs growth in two- and three-dimensional culture systems and their sarcosphere- and colony-forming ability. In addition, while miR-29b-1 overexpression sensitized 3AB-OS cells to chemotherapeutic drug-induced apoptosis, it did not influence their migratory and invasive capacities, thus suggesting a context-depending role of miR-29b-1. Using publicly available databases, we proceeded to identify potential miR-29b target genes, known to play a role in the above reported functions. Among these targets we analyzed CD133, N-Myc, CCND2, E2F1 and E2F2, Bcl-2 and IAP-2. We also analyzed the most important stemness markers as Oct3/4, Sox2 and Nanog. Real-time RT-PCR and western-blot analyses showed that miR-29b-1 negatively regulated the expression of these markers. Overall, the results show that miR-29b-1 suppresses stemness properties of 3AB-OS CSCs and suggest that developing miR-29b-1 as a novel
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Nanoparticle for delivery of antisense γPNA oligomers targeting CCR5
Bahal, Raman; McNeer, Nicole Ali; Ly, Danith H.; Saltzman, W. Mark; Glazer, Peter M.
2013-01-01
The development of a new class of peptide nucleic acids (PNAs), i.e., gamma PNAs (γPNAs), creates the need for a general and effective method for its delivery into cells for regulating gene expression in mammalian cells. Here we report the antisense activity of a recently developed hydrophilic and biocompatible diethylene glycol (miniPEG)-based gamma peptide nucleic acid called MPγPNAs via its delivery by poly(lactide-co-glycolide) (PLGA)-based nanoparticle system. We show that MPγPNA oligome...
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National Research Council Canada - National Science Library
Hale, Martha
2004-01-01
...) were extracted with cold Triton X-100. Western blotting revealed that Ib oligomers localized in DRMs extracted from Vero, but not MRC-5, cells while monomeric Ib was detected in the detergent-soluble fractions of both cell types...
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Prospective evaluation of the Alere i Influenza A&B nucleic acid amplification versus Xpert Flu/RSV.
Nguyen Van, J C; Caméléna, F; Dahoun, M; Pilmis, B; Mizrahi, A; Lourtet, J; Behillil, S; Enouf, V; Le Monnier, A
2016-05-01
The rapid and accurate detection of influenza virus in respiratory specimens is required for optimal management of patients with acute respiratory infections. Because of the variability of the symptoms and the numerous other causes of influenza-like illness, the diagnosis of influenza cannot be made on the basis of clinical criteria alone. Thus, rapid influenza diagnostic tests have been developed such as the Alere i Influenza A&B isothermal nucleic acid assay. We prospectively evaluated the performance of the Alere i Influenza A&B assay in comparison with our routine Xpert Flu/RSV assay. Positive samples were subtyped according to the protocol from the National Influenza Center (Paris, France). A total of 96 respiratory nasal swab samples were analyzed: with both methods, 38 were positive and 56 were negative. Samples were prospectively collected from January 20 to April 8, 2015, from patient (86 adult and 10 pediatric patients) presenting with an influenza-like illness through the French influenza season. In comparison with the Xpert Flu/RSV assay, the overall sensitivity and specificity of the Alere i Influenza A&B assay were 95% and 100%, respectively. Our results indicate that the Alere i Influenza A&B assay has a good overall analytical performance and a high degree of concordance with the PCR-based Xpert Flu/RSV assay. The Alere i Influenza A&B isothermal nucleic acid amplification test is a powerful tool for influenza detection due to its high sensitivity and specificity as well as its ability to generate results within 15min. Copyright © 2016 Elsevier Inc. All rights reserved.
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Rizzi, Matteo; Kullgren, Anders; Tingvall, Claes
2016-01-01
Several studies have reported the benefits of motorcycle antilock braking systems (ABS) in reducing injury crashes, due to improved stability and braking performance. Both aspects may prevent crashes but may also reduce the crash severity when a collision occurs. However, it is still unknown to what extent the reductions in injury crashes with ABS may be due to a combination of these mechanisms. Swedish hospital and police reports (2003-2012) were used. The risk for permanent medical impairment (RPMI) was calculated, showing the risk of at least 1 or 10% permanent medical impairment. In total, 165 crashes involving ABS-equipped motorcycles were compared with 500 crashes with similar motorcycles without ABS. The analysis was performed in 3 steps. First, the reduction in emergency care visits with ABS was calculated using an induced exposure approach. Secondly, the injury mitigating effects of ABS were investigated. The mean RPMI 1+ and RPMI 10+ were analyzed for different crash types. The distributions of impairing injuries (PMI 1+) and severely impairing injuries (PMI 10+) were also analyzed. In the third step, the total reduction of PMI 1+ and PMI 10+ injured motorcyclists was calculated by combining the reductions found in the previous steps. An additional analysis of combined braking systems (CBS) together with ABS was also performed. The results showed that emergency care visits were reduced by 47% with ABS. In the second step, it was found that the mean RPMI 1+ and RPMI 10+ with ABS were 15 and 37% lower, respectively. Finally, the third step showed that the total reductions in terms of crash avoidance and mitigation of PMI 1+ and PMI 10+ injured motorcyclists with ABS were 67 and 55%, respectively. However, PMI 1+ and PMI 10+ leg injuries were not reduced by ABS to the same extent. Indications were found suggesting that the benefits of ABS together with CBS may be greater than ABS alone. This article indicated that motorcycle ABS reduced impairing injuries
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Harker-Murray, Paul; Porter, Stephen B.; Merkel, Sarah C.; Londer, Aryel; Taylor, Dawn K.; Bina, Megan; Panoskaltsis-Mortari, Angela; Rubinstein, Pablo; Van Rooijen, Nico; Golovina, Tatiana N.; Suhoski, Megan M.; Miller, Jeffrey S.; Wagner, John E.; June, Carl H.; Riley, James L.
2008-01-01
Previously, we showed that human umbilical cord blood (UCB) regulatory T cells (Tregs) could be expanded approximately 100-fold using anti-CD3/28 monoclonal antibody (mAb)–coated beads to provide T-cell receptor and costimulatory signals. Because Treg numbers from a single UCB unit are limited, we explored the use of cell-based artificial antigen-presenting cells (aAPCs) preloaded with anti-CD3/28 mAbs to achieve higher levels of Treg expansion. Compared with beads, aAPCs had similar expansion properties while significantly increasing transforming growth factor β (TGF-β) secretion and the potency of Treg suppressor function. aAPCs modified to coexpress OX40L or 4-1BBL expanded UCB Tregs to a significantly greater extent than bead- or nonmodified aAPC cultures, reaching mean expansion levels exceeding 1250-fold. Despite the high expansion and in contrast to studies using other Treg sources, neither OX40 nor 4-1BB signaling of UCB Tregs reduced in vitro suppression. UCB Tregs expanded with 4-1BBL expressing aAPCs had decreased levels of proapoptotic bim. UCB Tregs expanded with nonmodified or modified aAPCs versus beads resulted in higher survival associated with increased Treg persistence in a xeno-geneic graft-versus-host disease lethality model. These data offer a novel approach for UCB Treg expansion using aAPCs, including those coexpressing OX40L or 4-1BBL. PMID:18645038
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International Nuclear Information System (INIS)
Gao, Mingzhang; Gao, Andy Chufan; Wang, Min; Zheng, Qi-Huang
2014-01-01
The reference standards 4a-b, 6a-b, 7a-c, and desmethylated precursors 9a-b, 10a-b, 8a-c were synthesized from 4-methoxyaniline, ethyl 2-chloro-acetoacetate and substituted benzene-1,2-diamines with 3, 5, 6 steps in 61–67%, 34–41%, 23–31%, and with 4, 6, 7 steps in 49–57%, 28–35%, 20–27% overall chemical yield, respectively. The target tracers [ 11 C]4a-b, [ 11 C]6a-b, [ 11 C]7a-c were synthesized from their corresponding precursors with [ 11 C]CH 3 OTf through O-[ 11 C]methylation and isolated by simplified SPE in 40–60% decay corrected radiochemical yields at EOB, with 185–370 GBq/μmol specific activity at EOS. - Highlights: • New 1,2,4-triazolo[4,3-a]quinoxalin-1-one derivatives were synthesized. • New 11 C-labeled 1,2,4-triazolo[4,3-a]quinoxalin-1-one derivatives were synthesized. • A simplified SPE technique was employed in radiosynthesis
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Attar, Aida; Bitan, Gal
2014-01-01
Despite decades of research, therapy for diseases caused by abnormal protein folding and aggregation (amyloidoses) is limited to treatment of symptoms and provides only temporary and moderate relief to sufferers. The failure in developing successful disease-modifying drugs for amyloidoses stems from the nature of the targets for such drugs - primarily oligomers of amyloidogenic proteins, which are distinct from traditional targets, such as enzymes or receptors. The oligomers are metastable, do not have well-defined structures, and exist in dynamically changing mixtures. Therefore, inhibiting the formation and toxicity of these oligomers likely will require out-of-the-box thinking and novel strategies. We review here the development of a strategy based on targeting the combination of hydrophobic and electrostatic interactions that are key to the assembly and toxicity of amyloidogenic proteins using lysine (K)-specific "molecular tweezers" (MTs). Our discussion includes a survey of the literature demonstrating the important role of K residues in the assembly and toxicity of amyloidogenic proteins and the development of a lead MT derivative called CLR01, from an inhibitor of protein aggregation in vitro to a drug candidate showing effective amelioration of disease symptoms in animal models of Alzheimer's and Parkinson's diseases.
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Thiessen, P. A.; Treder, H.-J.
Der gegenwärtige Stand der physikalischen Erkenntnis, in Sonderheit die Atomistik und die Quantentheorie, ermöglicht (in wohldefinierten Energie-Bereichen) eine ab initio-Berechnung aller physikalischen und chemischen Prozesse und Strukturen. Die Schrödinger-Gleichung erlaubt zusammen mit den Prinzipien der Quantenstatistik (Pauli-Prinzip) aus dem Planckschen Wirkungsquantum h und den atomischen Konstanten die Berechnung aller Energieumsätze, Zeitabläufe etc., die insbesondere die chemische Physik bestimmen. Die Rechenresultate gelten auch quantitativ bis auf die unvermeidliche Stochastik.Die ab initio-Berechnungen korrespondieren einerseits und sind andererseits komplementär zu den auf den Methoden der theoretischen Chemie und der klassischen Thermodynamik beruhenden Ergebnissen ex eventu. Die theoretische Behandlung ab initio führt zu mathematischen Experimenten, die die Laboratoriums-Experimente ergänzen oder auch substituieren.Translated AbstractAb initio vel ex eventuThe present state of physical knowledge, in peculiar atomistic and quantum theory, makes an ab initio calculation of all physical and chemical processes and structures possible (in well defined reaches of energy). The Schrödinger equation together with the principles of quantum statistics (Pauli principle) permits from the Planck and atomistic constants to calculate all exchanges of energy, courses of time, etc. which govern chemical physics. The calculated results are valid even quantitatively apart from the unavoidable stochastics.These ab initio calculations on the one hand correspond and are on the other complimentary to results ex eventu based on the methods of theoretical chemistry and classical thermodynamics. Theoretical treatment ab initio leads to mathematical experiments which add to or even substitute experiments in the laboratory.
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Shen, H D; Choo, K B; Chen, J H; Lin, W L; Chang, Z N; Han, S H
1992-04-01
A monoclonal antibody (MoAb P40) against the 68 kD major allergen of Penicillium notatum (P. notatum) was obtained by immunizing the mouse with a crude extract of P. notatum. Analysed by two-dimensional gel electrophoresis and immunoblotting, P40 reacted with two different isoforms of the 68 kD component of P. notatum with pIs of 5.4 and 5.5. In addition to P. notatum, P40 showed positive ELISA activity to Aspergillus fumigatus (A. fumigatus) but not to components of six other fungi including Alternaria porri, Cladosporium cladosporoides, Aureobasidium pullulans, Fusarium solani, Rhizopus arrhizus and Candida albicans. Analysed by ELISA, MoAb P40 also showed positive activity to two (P. frequentans and P. roseopurpureum) of the 10 other Penicillium species and two (A. terreus and A. flavus) of the four other Aspergillus species tested. SDS-PAGE and immunoblotting studies demonstrated P40 positive reactivity to components with MW of about 67 kD in all these Penicillium and Aspergillus species with positive ELISA activity to P40. Furthermore, immunoblotting activity of MoAb P40 to the 67 kD component of A. niger was also observed. The epitope of the 68 kD allergen of P. notatum recognized by MoAb P40 was resistant to treatment of periodate oxidation with concentration of NaIO4 up to 20 mM. This MoAb may thus be useful in the characterization and purification of the 68 kD allergen from crude extracts, and in the molecular cloning of allergen genes.
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2010-04-01
... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Introduction. 40.0-1 Section 40.0-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES EXCISE TAX PROCEDURAL REGULATIONS § 40.0-1 Introduction. (a) In general. The regulations in this part 40 are...
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Zijlstra, Niels
2014-01-01
During the last 15 years, we have witnessed a major shift in the research focus to understand the cause of amyloid diseases. The attention has shifted from the fully matured amyloid fibrils to the nanometer sized aggregation intermediates called oligomers as the potentially cytotoxic species that
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Ab-initio calculations of Co-based diluted magnetic semiconductors Cd 1-xCoxX (X=S, Se, Te)
Saeed, Yasir; Nazir, Safdar; Shaukat, Ali; Reshak, A. H.
2010-01-01
Ab-initio calculations are performed to investigate the structural, electronic and magnetic properties of spin-polarized diluted magnetic semiconductors composed of IIVI compounds Cd1-xCoxX (X=S, Se, Te) at x=0.25. From the calculated results
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Energy Technology Data Exchange (ETDEWEB)
Jung, Young Min; Park, Young Tae [Dept. of Chemistry, Keimyung University, Daegu (Korea, Republic of); Baek, Seong Ho [Div. of Green Energy Research, Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of)
2017-01-15
We oligomerized 2,5-dibromo-1,1-diisopropyl-3,4-diphenyl-2,5-silole with dichloroalkylphenylsilanes utilizing n-BuLi to yield conjugated oligo [(1,1-diisopropyl-3,4-diphenyl-2,5-silolene)-co-(alkylphenylsilylene)]s. Gel permeation chromatography measurements confirm that the synthesized materials are oligomeric. In addition, the prepared oligomers show characteristic diene stretching bands at 1579–1599 cm{sup −1} in their FT-IR spectra. Furthermore, the oligomers are highly soluble in common organic solvents such as tetrahydrofuran and chloroform. In tetrahydrofuran, the oligomers show strong maximum electronic absorption bands at 253–292 nm with molar absorptivities of 1.61 × 10{sup 2} to 2.57 × 10{sup 4} /cm M in their UV–vis electronic absorption spectra, indicating that the maxima are red-shifted by 5–8 nm compared to the 2,5-dibromo-1,1-diisopropyl-3,4-diphenyl-2,5-silole monomer, strong maximum electronic excitation bands at 292–312 nm, and strong maxima electronic emission bands at 385–396 nm in the emission fluorescence spectra. The emission and absorption spectra strongly suggest that the prepared silole-containing oligomers may be conjugated through the oligomer backbone. In particular, cyclic voltammetry measurements of oligo[(1,1-diisopropyl-3,4-diphenyl-2,5-silolene)-co-(diphenylsilylene)] deposited on a glassy carbon electrode in 1.0 M aqueous hydrogen chloride show two oxidation potentials at 0.98 and 1.61 V vs. Ag/Ag{sup +}, and two reduction potentials at 0.00 and −1.93 V vs. Ag/Ag{sup +}. The oligomers were stable on heating to 200 °C under nitrogen, as determined by thermogravimetric analysis, losing between 4% and 23% of their starting weights.
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Directory of Open Access Journals (Sweden)
Bankanidhi Sahoo
Full Text Available Expansion of the polyglutamine (polyQ track of the Huntingtin (HTT protein above 36 is associated with a sharply enhanced risk of Huntington's disease (HD. Although there is general agreement that HTT toxicity resides primarily in N-terminal fragments such as the HTT exon1 protein, there is no consensus on the nature of the physical states of HTT exon1 that are induced by polyQ expansion, nor on which of these states might be responsible for toxicity. One hypothesis is that polyQ expansion induces an alternative, toxic conformation in the HTT exon1 monomer. Alternative hypotheses posit that the toxic species is one of several possible aggregated states. Defining the nature of the toxic species is particularly challenging because of facile interconversion between physical states as well as challenges to identifying these states, especially in vivo. Here we describe the use of fluorescence correlation spectroscopy (FCS to characterize the detailed time and repeat length dependent self-association of HTT exon1-like fragments both with chemically synthesized peptides in vitro and with cell-produced proteins in extracts and in living cells. We find that, in vitro, mutant HTT exon1 peptides engage in polyQ repeat length dependent dimer and tetramer formation, followed by time dependent formation of diffusible spherical and fibrillar oligomers and finally by larger, sedimentable amyloid fibrils. For expanded polyQ HTT exon1 expressed in PC12 cells, monomers are absent, with tetramers being the smallest molecular form detected, followed in the incubation time course by small, diffusible aggregates at 6-9 hours and larger, sedimentable aggregates that begin to build up at 12 hrs. In these cell cultures, significant nuclear DNA damage appears by 6 hours, followed at later times by caspase 3 induction, mitochondrial dysfunction, and cell death. Our data thus defines limits on the sizes and concentrations of different physical states of HTT exon1 along the
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Karovska, Margarita
2003-09-01
The nearby system Mira AB composed of an aging AGB star (Mira A) and a WD companion (Mira B) offers a unique laboratory for studying wind accretion processes, a poorly understood phenomenon in many sources. Recent Chandra ACIS-S Obs.(70ks on 12/6/03; PI.M.Karovska) resolved for the first time the components (~0.6") in X-rays, and detected a new bright soft source (A. This is the first detection of X-rays from an AGB star. This source was not detected by ROSAT in 1993 or recently by XMM 8/03 (AAS/03,J.Kastner), and could be a transient phenomenon. Model fitting shows that the soft X-ray emission is likely several emission lines, rather then a continuum; with ACIS spectral resolution we cannot resolve or identify these lines. We propose a 40ks LETG+HRC-S obs. to identify the lines and determine the emission mechanism.
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Chemical evolution. XXI - The amino acids released on hydrolysis of HCN oligomers
Ferris, J. P.; Wos, J. D.; Nooner, D. W.; Oro, J.
1974-01-01
Major amino acids released by hydrolysis of acidic and basic HCN oligomers are identified by chromatography as Gly, Asp, and diaminosuccinic acid. Smaller amounts of Ala, Ile and alpha-aminoisobutyric acid are also detected. The amino acids released did not change appreciably when the hydrolysis medium was changed from neutral to acidic or basic. The presence of both meso and d, l-diaminosuccinic acids was established by paper chromatography and on an amino acid analyzer.
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Influence of Cellulose on the Mechanical and Thermal Stability of ABS Plastic Composites
Directory of Open Access Journals (Sweden)
K. Crews
2016-01-01
Full Text Available Microcrystalline cellulose was explored as possible biodegradable fillers in the fabrication of ABS plastic composites. TGA indicates that upon inclusion of cellulose microcrystals the thermal stability of the ABS plastics was improved significantly when compared to the neat ABS plastic counterparts. Furthermore, inclusion of extracted cellulose from plant biomass showed a higher thermal stability with maximum decomposition temperatures around 131.95°C and 124.19°C for cellulose from cotton and Hibiscus sabdariffa, respectively, when compared to that of the purchased cellulose. In addition, TMA revealed that the average CTE value for the neat ABS and 1 : 1 ratio of cellulose to ABS fabricated in this study was significantly lower than the reported CTE (ca. 73.8 μm/m°C.
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Conformation of chromatin oligomers. A new argument for a change with the hexanucleosome.
Marion, C; Bezot, P; Hesse-Bezot, C; Roux, B; Bernengo, J C
1981-11-01
Quasielastic laser light scattering measurements have been made on chromatin oligomers to obtain information on the transition in their electrooptical properties, previously observed for the hexameric structures [Marion, C. and Roux, B. (1978) Nucleic Acids Res. 5, 4431-4449]. Translational diffusion coefficients were determined for mononucleosomes to octanucleosomes containing histone H1 over a range of ionic strength. At high ionic strength, oligomers show a linear dependence of the logarithm of diffusion coefficient upon the logarithm of number of nucleosomes. At low ionic strength a change occurs between hexamer and heptamer. Our results agree well with the recent sedimentation data of Osipova et al. [Eur. J. Biochem. (1980) 113, 183-188] and of Butler and Thomas [J. Mol. Biol. (1980) 140, 505-529] showing a change in stability with hexamer. Various models for the arrangements of nucleosomes in the superstructure of chromatin are discussed. All calculations clearly indicate a conformational change with the hexanucleosome and the results suggest that, at low ionic strength, the chromatin adopts a loosely helical structure of 28-nm diameter and 22-nm pitch. These results are also consistent with a discontinuity every sixth nucleosome, corresponding to a turn of the helix. This discontinuity may explain the recent electric dichroism data of Lee et al. [Biochemistry (1981) 20, 1438-1445]. The hexanucleosome structure which we have previously suggested, with the faces of nucleosomes arranged radially to the helical axis has been recently confirmed by Mc Ghee et al. [Cell (1980) 22, 87-96]. With an increase of ionic strength, the helix becomes more regular and compact with a slightly reduced outer diameter and a decreased pitch, the dimensions resembling those proposed for solenoid models.
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Imamura, N; Tanaka, R; Kajihara, H; Kuramoto, A
1988-11-01
In this study, pretreatment peripheral and/or bone marrow blasts from 12 patients with acute unclassifiable leukemia (AUL) expressing the myeloid-related cell-surface antigen (CD 11) were isolated for further analysis. Despite a lack of myeloperoxidase (MPO) activity, 1 patient's blasts contained cytoplasmic Auer rods. The circulating blasts from another patient expressed MPO while maintaining the same surface phenotype during 20 months of clinical follow-up. In addition, the blasts from 3 cases demonstrated both myelomonocytic and monocyte-specific surface antigens, whereas the remaining 9 cases completely lacked any monocyte-specific antigen detectable by monoclonal antibodies, Mo2, My4 and Leu M3 (CD 14). The first case eventually was diagnosed as acute myelomonocytic leukemia and the second as acute myelogenous leukemia by means of immunophenotypic analysis using flow cytometry (FACS IV). In addition, the presence of MPO protein was identified in the cytoplasm of blast cells from 5 patients with AUL by means of a cytoplasmic immunofluorescence test using a monoclonal antibody (MA1). Our study indicates that non-T, non-B AUL expressing OKM1 (CD 11) antigens include acute leukemias which are unequivocally identifiable as being of either myeloid or myelomonocytic origin. However, further investigations, including immunophenotypic and cytoplasmic analysis, ultrastructural cytochemistry and gene analysis with molecular probes (tests applicable to normal myeloid cells), are necessary in order to determine the actual origin of blasts and to recognize the differentiation stages of the various types of leukemic cells from patients with undifferentiated forms of leukemia.
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Therapeutic potential of an anti-high mobility group box-1 monoclonal antibody in epilepsy.
Zhao, Junli; Wang, Yi; Xu, Cenglin; Liu, Keyue; Wang, Ying; Chen, Liying; Wu, Xiaohua; Gao, Feng; Guo, Yi; Zhu, Junming; Wang, Shuang; Nishibori, Masahiro; Chen, Zhong
2017-08-01
Brain inflammation is a major factor in epilepsy, and the high mobility group box-1 (HMGB1) protein is known to contribute significantly to the generation of seizures. Here, we investigated the therapeutic potential of an anti-HMGB1 monoclonal antibody (mAb) in epilepsy. anti-HMGB1 mAb attenuated both acute seizure models (maximal electroshock seizure, pentylenetetrazole-induced and kindling-induced), and chronic epilepsy model (kainic acid-induced) in a dose-dependent manner. Meanwhile, the anti-HMGB1 mAb also attenuated seizure activities of human brain slices obtained from surgical resection from drug-resistant epilepsy patients. The mAb showed an anti-seizure effect with a long-term manner and appeared to be minimal side effects at even very high dose (no disrupted physical EEG rhythm and no impaired basic physical functions, such as body growth rate and thermoregulation). This anti-seizure effect of mAb results from its inhibition of translocated HMGB1 from nuclei following seizures, and the anti-seizure effect was absent in toll-like receptor 4 knockout (TLR4 -/- ) mice. Interestingly, the anti-HMGB1 mAb also showed a disease-modifying anti-epileptogenetic effect on epileptogenesis after status epileptics, which is indicated by reducing seizure frequency and improving the impaired cognitive function. These results indicate that the anti-HMGB1 mAb should be viewed as a very promising approach for the development of novel therapies to treat refractory epilepsy. Copyright © 2017 Elsevier Inc. All rights reserved.
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Delocalization of Coherent Triplet Excitons in Linear Rigid Rod Conjugated Oligomers.
Hintze, Christian; Korf, Patrick; Degen, Frank; Schütze, Friederike; Mecking, Stefan; Steiner, Ulrich E; Drescher, Malte
2017-02-02
In this work, the triplet state delocalization in a series of monodisperse oligo(p-phenyleneethynylene)s (OPEs) is studied by pulsed electron paramagnetic resonance (EPR) and pulsed electron nuclear double resonance (ENDOR) determining zero-field splitting, optical spin polarization, and proton hyperfine couplings. Neither the zero-field splitting parameters nor the optical spin polarization change significantly with OPE chain length, in contrast to the hyperfine coupling constants, which showed a systematic decrease with chain length n according to a 2/(1 + n) decay law. The results provide striking evidence for the Frenkel-type nature of the triplet excitons exhibiting full coherent delocalization in the OPEs under investigation with up to five OPE repeat units and with a spin density distribution described by a nodeless particle in the box wave function. The same model is successfully applied to recently published data on π-conjugated porphyrin oligomers.
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Effects of CD44 Ligation on Signaling and Metabolic Pathways in Acute Myeloid Leukemia
Madhoun, Nour Y.
2017-01-01
Acute myeloid leukemia (AML) is characterized by a blockage in the differentiation of myeloid cells at different stages. CD44-ligation using anti-CD44 monoclonal antibodies (mAbs) has been shown to reverse the blockage of differentiation
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[Acute intoxication with fenspiride].
Chodorowski, Zygmunt; Sein Anand, Jacek; Korolkiewicz, Roman
2004-01-01
According to the best of our knowledge this is the first publication in medical literature about the acute intoxication with fenspiride. The two cases of a young female patients, intoxicated with Eurespal, were described. The orthostatic hypotonia with the blood pressure about 105-115/70 mm Hg in the horizontal position and 70-80/40 mm Hg in the sitting position was dominating. The heart rate was 100-110/min. when lying and 130-140/min. when sitting. The main symptoms were probably caused by inhibition of alpha1 adrenergic receptors. Main clinical manifestations make us reconsider the opinion about safety of fenspiride especially after acute intoxication.
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Effects of CD44 Ligation on Signaling and Metabolic Pathways in Acute Myeloid Leukemia
Madhoun, Nour Y.
2017-04-01
Acute myeloid leukemia (AML) is characterized by a blockage in the differentiation of myeloid cells at different stages. CD44-ligation using anti-CD44 monoclonal antibodies (mAbs) has been shown to reverse the blockage of differentiation and to inhibit the proliferation of blasts in most AML-subtypes. However, the molecular mechanisms underlying this property have not been fully elucidated. Here, we sought to I) analyze the effects of anti-CD44 mAbs on downstream signaling pathways, including the ERK1/2 (extracellular signal-regulated kinase 1 and 2) and mTOR (mammalian target of rapamycin) pathways and II) use state-of-the-art Nuclear Magnetic Resonance (NMR) technology to determine the global metabolic changes during differentiation induction of AML cells using anti-CD44 mAbs and other two previously reported differentiation agents. In the first objective (Chapter 4), our studies provide evidence that CD44-ligation with specific mAbs in AML cells induced an increase in ERK1/2 phosphorylation. The use of the MEK inhibitor (U0126) significantly inhibited the CD44-induced differentiation of HL60 cells, suggesting that ERK1/2 is critical for the CD44-triggered differentiation in AML. In addition, this was accompanied by a marked decrease in the phosphorylation of the mTORC1 and mTORC2 complexes, which are strongly correlated with the inhibition of the PI3K/Akt pathway. In the second objective (Chapter 5), 1H NMR experiments demonstrated that considerable changes in the metabolic profiles of HL60 cells were induced in response to each differentiation agent. These most notable metabolites that significantly changed upon CD44 ligation were involved in the tricarboxylic acid (TCA) cycle and glycolysis such as, succinate, fumarate and lactate. Therefore, we sought to analyze the mechanisms underlying their alterations. Our results revealed that anti-CD44 mAbs treatment induced upregulation in fumarate hydratase (FH) expression and its activity which was accompanied by a
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Acute Appendicitis as the Initial Clinical Presentation of Primary HIV-1 Infection
DEFF Research Database (Denmark)
Schleimann, Mariane H; Leth, Steffen; Krarup, Astrid R
2018-01-01
We report a case of an adolescent who presented at our emergency department with acute abdominal pain. While the initial diagnosis was acute appendicitis, a secondary and coincidental diagnosis of primary HIV-1 infection was made. Concurrent and subsequent clinical and molecular biology findings ...... form the basis of our argument that primary HIV-1 infection was the cause of acute appendicitis in this individual.......We report a case of an adolescent who presented at our emergency department with acute abdominal pain. While the initial diagnosis was acute appendicitis, a secondary and coincidental diagnosis of primary HIV-1 infection was made. Concurrent and subsequent clinical and molecular biology findings...
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Pragman, Alexa A; Yarwood, Jeremy M; Tripp, Timothy J; Schlievert, Patrick M
2004-04-01
Workers in our laboratory have previously identified the staphylococcal respiratory response AB (SrrAB), a Staphylococcus aureus two-component system that acts in the global regulation of virulence factors. This system down-regulates production of agr RNAIII, protein A, and toxic shock syndrome toxin 1 (TSST-1), particularly under low-oxygen conditions. In this study we investigated the localization and membrane orientation of SrrA and SrrB, transcription of the srrAB operon, the DNA-binding properties of SrrA, and the effect of SrrAB expression on S. aureus virulence. We found that SrrA is localized to the S. aureus cytoplasm, while SrrB is localized to the membrane and is properly oriented to function as a histidine kinase. srrAB has one transcriptional start site which results in either an srrA transcript or a full-length srrAB transcript; srrB must be cotranscribed with srrA. Gel shift assays of the agr P2, agr P3, protein A (spa), TSST-1 (tst), and srr promoters revealed SrrA binding at each of these promoters. Analysis of SrrAB-overexpressing strains by using the rabbit model of bacterial endocarditis demonstrated that overexpression of SrrAB decreased the virulence of the organisms compared to the virulence of isogenic strains that do not overexpress SrrAB. We concluded that SrrAB is properly localized and oriented to function as a two-component system. Overexpression of SrrAB, which represses agr RNAIII, TSST-1, and protein A in vitro, decreases virulence in the rabbit endocarditis model. Repression of these virulence factors is likely due to a direct interaction between SrrA and the agr, tst, and spa promoters.
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Solvent (acetone-butanol: ab) production
This article describes production of butanol [acetone-butanol-ethanol, (also called AB or ABE or solvent)] by fermentation using both traditional and current technologies. AB production from agricultural commodities, such as corn and molasses, was an important historical fermentation. Unfortunately,...
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Characterization of radiation modified κ-carrageenan oligomers for bio-based materials development
International Nuclear Information System (INIS)
Abad, Lucille V.; Relleve, Lorna S.; Aranilla, Charito T.; Racadio, Darwin T.; Dela Rosa, Alumanda M.
2011-01-01
κ-carrageenan oligomers are known to have several biological activities such as anti-HIV, anti-herpes, antitumor and antioxidant properties. Recent progress in the development of radiation modified κ-carrageenan has resulted in new applications such as plant growth promoter, radiation dose indicator and hydrogels for wound dressing. This presentation would touch on the changes in chemical structure, gelation and conformational transition behavior and molecular size of κ-carrageenan at doses from 0 to 200 kGy and would be correlated to these functions for the development of bio-based materials. Chemical and spectral analyses were carried out using UV-Vis spectroscopy, FT-IR spectroscopy, NMR spectroscopy, reducing sugar analysis, free sulfate and carboxylic acid analysis. The chemical and spectral analyses of the radiolytic products indicated increasing reducing sugars, carbonyl, carboxylic acids, and sulfates with increasing doses which reached a maximum level at a certain dose depending on the irradiation condition. Values were very much lower in solid irradiation (in vacuum and in air) as compared to aqueous irradiation. NMR data also revealed an intact structure of the oligomer irradiated at 100 kGy in the specific fraction that contains an Mw = (3-10) kDa. κ-carrageenan oligomers exhibited antioxidant properties as determined by hydroxyl radical scavenging activity, reducing power and DPPH radical scavenging capacity assay. The degree of oxidative inhibition increased with increasing dose which can be attributed to higher reducing sugar. Dynamic light scattering (DLS) experiments showed that a dose of up to 50 kGy, sol-gelation transition was still observed. Beyond 50 kGy, no gelation took place, instead appearance of fast relax-carrageenan mode in characteristic decay time function was observed at doses of (75-150) kGy. Optimum peak intensity was found at 100 kGy (mol wt. 5-10 kDa) which coincides with the optimum plant growth promoter effect in κ
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Behzad, Somayeh
2016-09-01
Monolayer α-graphyne is a new two-dimensional carbon allotrope with many special features. In this work the electronic properties of AA- and AB-stacked bilayers of this material and then the optical properties are studied, using first principle plane wave method. The electronic spectrum has two Dirac cones for AA stacked bilayer α-graphyne. For AB-stacked bilayer, the interlayer interaction changes the linear bands into parabolic bands. The optical spectra of the most stable AB-stacked bilayer closely resemble to that of the monolayer, except for small shifts of peak positions and increasing of their intensity. For AB-stacked bilayer, a pronounced peak has been found at low energies under the perpendicular polarization. This peak can be clearly ascribed to the transitions at the Dirac point as a result of the small degeneracy lift in the band structure.
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Liu, Mingming; Huang, Rong; Weisman, Adam; Yu, Xiaoyang; Lee, Shih-Hui; Chen, Yalu; Huang, Chao; Hu, Senhua; Chen, Xiuhua; Tan, Wenfeng; Liu, Fan; Chen, Hao; Shea, Kenneth J
2018-05-24
We report a novel strategy for creating abiotic Bacillus thuringiensis ( Bt) protein affinity ligands by biomimicry of the recognition process that takes place between Bt Cry1Ab/Ac proteins and insect receptor cadherin-like Bt-R 1 proteins. Guided by this strategy, a library of synthetic polymer nanoparticles (NPs) was prepared and screened for binding to three epitopes 280 FRGSAQGIEGS 290 , 368 RRPFNIGINNQQ 379 and 436 FRSGFSNSSVSIIR 449 located in loop α8, loop 2 and loop 3 of domain II of Bt Cry1Ab/Ac proteins. A negatively charged and hydrophilic nanoparticle (NP12) was found to have high affinity to one of the epitopes, 368 RRPFNIGINNQQ 379 . This same NP also had specific binding ability to both Bt Cry1Ab and Bt Cry1Ac, proteins that share the same epitope, but very low affinity to Bt Cry2A, Bt Cry1C and Bt Cry1F closely related proteins that lack epitope homology. To locate possible NP- Bt Cry1Ab/Ac interaction sites, NP12 was used as a competitive inhibitor to block the binding of 865 NITIHITDTNNK 876 , a specific recognition site in insect receptor Bt-R 1 , to 368 RRPFNIGINNQQ 379 . The inhibition by NP12 reached as high as 84%, indicating that NP12 binds to Bt Cry1Ab/Ac proteins mainly via 368 RRPFNIGINNQQ 379 . This epitope region was then utilized as a "target" or "bait" for the separation and concentration of Bt Cry1Ac protein from the extract of transgenic Bt cotton leaves by NP12. This strategy, based on the antigen-receptor recognition mechanism, can be extended to other biotoxins and pathogen proteins when designing biomimic alternatives to natural protein affinity ligands.
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Milton, James A.; Patole, Samson; Yin, Huabing; Xiao, Qiang; Brown, Tom; Melvin, Tracy
2013-01-01
Although strategies for the immobilization of DNA oligonucleotides onto surfaces for bioanalytical and top-down bio-inspired nanobiofabrication approaches are well developed, the effect of introducing spacer molecules between the surface and the DNA oligonucleotide for the hybridization of nanoparticle–DNA conjugates has not been previously assessed in a quantitative manner. The hybridization efficiency of DNA oligonucleotides end-labelled with gold nanoparticles (1.4 or 10 nm diameter) with DNA sequences conjugated to silicon surfaces via hexaethylene glycol phosphate diester oligomer spacers (0, 1, 2, 6 oligomers) was found to be independent of spacer length. To quantify both the density of DNA strands attached to the surfaces and hybridization with the surface-attached DNA, new methodologies have been developed. Firstly, a simple approach based on fluorescence has been developed for determination of the immobilization density of DNA oligonucleotides. Secondly, an approach using mass spectrometry has been created to establish (i) the mean number of DNA oligonucleotides attached to the gold nanoparticles and (ii) the hybridization density of nanoparticle–oligonucleotide conjugates with the silicon surface–attached complementary sequence. These methods and results will be useful for application with nanosensors, the self-assembly of nanoelectronic devices and the attachment of nanoparticles to biomolecules for single-molecule biophysical studies. PMID:23361467
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2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Counsel. 1.07-40 Section 1.07-40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL GENERAL PROVISIONS Enforcement; Civil and Criminal Penalty Proceedings § 1.07-40 Counsel. A party has the right to be represented...
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Ab Initio Description of Disordered Sr1−xKxFe2As2 Using the Coherent Potential Approximation
Pulikkotil, J. J.; Schwingenschlö gl, Udo
2010-01-01
The electronic structure of disordered Sr1−xKxFe2As2 is studied by ab initio density functional theory. As no superstructure and/or atomic short range ordering is reported for Sr1−xKxFe2As2, the coherent potential approximation can be used
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Rajak, Poonam; Vijayalakshmi, M A; Jayaprakash, N S
2013-05-05
Proteins present in human serum are of immense importance in the field of biomarker discovery. But, the presence of high-abundant proteins like albumin makes the analysis more challenging because of masking effect on low-abundant proteins. Therefore, removal of albumin using highly specific monoclonal antibodies (mAbs) can potentiate the discovery of low-abundant proteins. In the present study, mAbs against human serum albumin (HSA) were developed and integrated in to an immunoaffinity based system for specific removal of albumin from the serum. Hybridomas were obtained by fusion of Sp2/0 mouse myeloma cells with spleen cells from the mouse immunized with HSA. Five clones (AHSA1-5) producing mAbs specific to HSA were established and characterized by enzyme linked immunosorbent assay (ELISA) and immunoblotting for specificity, sensitivity and affinity in terms of antigen binding. The mAbs were able to bind to both native albumin as well as its glycated isoform. Reactivity of mAbs with different mammalian sera was tested. The affinity constant of the mAbs ranged from 10(8) to 10(9)M(-1). An approach based on oriented immobilization was followed to immobilize purified anti-HSA mAbs on hydrazine activated agarose gel and the dynamic binding capacity of the column was determined. Copyright © 2013 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Helena Porta
2011-01-01
Full Text Available Bacillus thuringiensis produces crystal toxins known as Cry that are highly selective against important agricultural and human health-related insect pests. Cry proteins are pore-forming toxins that interact with specific receptors in the midgut cell membrane of susceptible larvae making pores that cause osmotic shock, leading finally to insect death. In the case of pore-forming toxins that are specific to mammalian cells, death responses at low doses may induce apoptosis or pyroptosis, depending on the cell type. The death mechanism induced by Cry toxins in insect midgut cells is poorly understood. Here, we analyze the caspases expression by RT-PCR analysis, showing that the initial response of Manduca sexta midgut cells after low dose of Cry1Ab toxin administration involves a fast and transient accumulation of caspase-1 mRNA, suggesting that pyroptosis was activated by Cry1Ab toxin as an initial response but was repressed later. In contrast, caspase-3 mRNA requires a longer period of time of toxin exposure to be activated but presents a sustained activation, suggesting that apoptosis may be a cell death mechanism induced also at low dose of toxin.
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Sunaryo, Y.; Purnomo, D.; Darini, M. T.; Cahyani, V. R.
2018-03-01
Hydroponic as one of the protected cultivation practices is very important to be developed in Indonesia due to not only the reduction of arable agricultural lands in lines with increasing of residential demand and other public facilities but also due to the negative influences of climate change as well global warming to plant growth. The effects of liquid fertilizer made from goat manure (LFGM) in combination with AB-Mix on three kinds of foliage vegetable growth was examined in hydroponics. The research was conducted by 3 x 4 factorial experiment and arranged in Completely Randomized Design with 3 replications. The first factor was foliage vegetable consisting of 3 levels: Mustard Green, Lettuce, and Red Spinach. The second factor was the mixture composition of nutrient solution consisting of 4 levels: LFGM + AB-Mix (v/v: 1:1), LFGM + AB-Mix (v/v: 1:3), LFGM + AB-Mix (v/v: 3:1), and A/B mix as control. Results indicated that the application of LFGM + AB-Mix (v/v: 1:3) resulted in similar plant growth as control (AB-Mix application), and also resulted in the highest chlorophyll content of Mustard green.
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Directivity of the radio emission from the K1 dwarf star AB Doradus
Lim, Jeremy; White, Stephen M.; Nelson, Graam J.; Benz, Arnold O.
1994-01-01
We present measurements of the spectrum and polarization of the flaring radio emission from the K1 dwarf star AB Doradus, together with previously reported single frequency measurements (with no polarization information) on 3 other days. On all 4 days spanning a 6 month period, the emission was strong and, when folded with the stellar rotation period, showed similar time variations with two prominant peaks at phase 0.35 and 0.75. These peaks coincide in longitude with two large starspots identified from the stellar optical light curve and have half-powe widths as small as 0.1 rotations and no larger than 0.2 rotations. The modulated emission shows no measurable circular polarization, and its two peaks have different turnover frequencies.
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American brachytherapy society (ABS) consensus guidelines for brachytherapy of esophageal cancer
International Nuclear Information System (INIS)
Gaspar, Laurie E.; Nag, Subir; Herskovic, Arnold; Mantravadi, Rao; Speiser, Burton
1997-01-01
LDR of 25-40 Gy at 0.4-1 Gy/hr may be of benefit. Conclusion: ABS guidelines for esophageal brachytherapy now exist and will be updated by the ABS in the future, as clinical data using more uniform treatment techniques becomes available
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Úbeda, Sara; Aznar, Margarita; Vera, Paula; Nerín, Cristina; Henríquez, Luis; Taborda, Laura; Restrepo, Claudia
2017-10-01
Most multilayer high barrier materials used in food packaging have a polyurethane adhesive layer in their structures. In order to assess the safety of these materials, it is important to determine the compounds intentionally added to the adhesives (IAS) as well as those non-intentionally added substances (NIAS). During the manufacture of polyurethane adhesives, some by-products can be formed, such as cyclic polyester oligomers coming from the reaction between dicarboxylic acids and glycols. Since these compounds are not listed in the Regulation 10/2011/EU, they should not be found in migration above 0.01 mg/kg of simulant. In this study two flexible multilayer packaging materials were used and migration was evaluated in simulant A (ethanol 10% v/v), simulant B (acetic acid 3% w/v) and simulant ethanol 95% v/v during 10 days at 60ºC. Identification and quantification of non-volatile compounds was carried out by UPLC-MS-QTOF. Most of migrants were oligomers such as cyclic polyesters and caprolactam oligomers. Overall migration and specific migration of adipic acid-diethylene glycol and phthalic acid-diethylene glycol were monitored over time and analysed by UPLC-MS-TQ. In most cases, ethanol 95% v/v was the simulant with the highest concentration values. Overall migration kinetics followed a similar pattern than specific migration kinetics.
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A SUBCHRONIC INHALATION STUDY OF FISCHER 344 RATS EXPOSED TO 0, 0.4, 1.4 OR 4.0 PPM ACROLEIN
International Nuclear Information System (INIS)
KUTZMAN, R.S.
1981-01-01
Fischer 344 rats were exposed to 0.0, 0.4, 1.4, or 4.0 ppm acrolein for 62 days. The major objective of the study was to relate the results of a series of pulmonary function tests to biochemical and pathological alterations observed in the lung. Cytological and reproductive potential endpoints were also assessed after acrolein exposure. Rats were exposed to acrolein for 6 hours/day, 5 days/week for 62 days. Mortality was observed only in the 4.0 ppm chamber where 32 of 57 exposed males died; however, none of the 8 exposed females died. Most of the mortality occurred within the first 10 exposure days. Histologic examination indicated that the animals died of acute bronchopneumonia. The surviving males and females exposed to 4.0 ppm acrolein gained weight at a significantly slower rate than control animals. The growth of both sexes in the 0.4 and 1.4 ppm groups was similar to that of their respective controls. Histopathologic examination of animals after 62 days of exposure revealed bronchiolar epithelial necrosis and sloughing, bronchiolar edema with macrophages, and focal pulmonary edema in the 4.0 ppm group. These lesions were, in some cases, associated with edema of the trachea and peribronchial lymph nodes, and acute rhinitis which indicated an upper respiratory tract effect of acrolein. Of particular interest was the variability of response between rats in the 4.0 ppm group, some not affected at all while others were moderately affected. Intragroup variability in toxicity was also apparent in the 1.4 ppm exposure group where only 3 of 31 animals examined had lesions directly related to acrolein exposure. Extra respiratory organs appeared unaffected
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Directory of Open Access Journals (Sweden)
Sudhanshu Kashyap
2013-01-01
Full Text Available The theoretical homology based structural model of Cry1Ab15 δ-endotoxin produced by Bacillus thuringiensis BtB-Hm-16 was predicted using the Cry1Aa template (resolution 2.25 Å. The Cry1Ab15 resembles the template structure by sharing a common three-domain extending conformation structure responsible for pore-forming and specificity determination. The novel structural differences found are the presence of β0 and α3, and the absence of α7b, β1a, α10a, α10b, β12, and α11a while α9 is located spatially downstream. Validation by SUPERPOSE and with the use of PROCHECK program showed folding of 98% of modeled residues in a favourable and stable orientation with a total energy Z-score of −6.56; the constructed model has an RMSD of only 1.15 Å. These increments of 3D structure information will be helpful in the design of domain swapping experiments aimed at improving toxicity and will help in elucidating the common mechanism of toxin action.
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Clinical significance of detection of GAD-Ab, ICA and IAA in patients with diabetes mellitus
International Nuclear Information System (INIS)
Zhou Jinhong; Liu Zhenzong; Wang Huimin
2006-01-01
To explore value of combined detection of glutamic acid decarboxylase antibody(GAD-Ab), islet cell antibody (ICA) and insulin autoantibody (IAA) in patients with diabetes mellitus (DM). Serum GAD-Ab, ICA and IAA were detected by chemiluminescent immunoassay and RIA in 46 of type 1 diabetes mellitus (1 DM), 78 of 2 DM respectively, and in 50 nondiabetic subjects as control group, and analysed according to the positive rates of different groups. Results showed that the positive rate of GAD-Ab was 67.39%, ICA 39.73%, IAA 23.91% in 1 DM,and that of GAD-Ab was 8.97%, ICA 15.39%, IAA 10.26% in 2 DM respectively. The positive rate of combined detection of GAD-Ab, ICA and IAA was 91.30% in patients with 1 DM, and 29.49% which was higher than that in control group (P<0.01). The detection of serum GAD-Ab,ICA and IAA might be regarded as clinical significance for classification, treatment and predict prognosis of DM. (authors)
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DEFF Research Database (Denmark)
Kasch, Helge; Qerama, Erisela; Kongsted, Alice
2011-01-01
One-year prospective study of 141 acute whiplash patients (WLP) and 40 acute ankle-injured controls.......One-year prospective study of 141 acute whiplash patients (WLP) and 40 acute ankle-injured controls....
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DEFF Research Database (Denmark)
Sørensen, Nanna Skall; Tegtmeier, C.; Andresen, Lars Ole
2006-01-01
The pig acute phase protein (APP) response to experimental Streptococcus suis (S. suis) infection was mapped by the measurement of the positive APPs C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp) and major acute phase protein (pig-MAP) and the negative APPs albumin...... and apolipoprotein (Apo) A-I. The aim was to elucidate the differences in the acute phase behaviour of the individual APPs during a typical bacterial septicaemic, infection. Pigs were inoculated subcutaneously with live S. suis serotype 2 and blood was sampled before and on various days post inoculation (p...... the experiment with maximum levels around 10 times the day 0-levels, and pig-MAP was elevated on days 1-12 p.i. with peak levels of around seven times the day 0-levels. Apo A-I was decreased from days 1 to 8 and showed minimum levels of about 40% of day 0-levels around 1-2 days p.i. No clear pattern of changes...
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Directory of Open Access Journals (Sweden)
B.M. Ribeiro
1998-06-01
Full Text Available The administration of baculoviruses to insects for bioassay purposes is carried out, in most cases, by contamination of food surfaces with a known amount of occlusion bodies (OBs. Since per os infection is the natural route of infection, occluded recombinant viruses containing crystal protein genes (cry1Ab and cry1Ac from Bacillus thuringiensis were constructed for comparison with the baculovirus prototype Autographa californica nucleopolyhedrovirus (AcNPV. The transfer vector pAcUW2B was used for construction of occluded recombinant viruses. The transfer vector containing the crystal protein genes was cotransfected with linearized DNA from a non-occluded recombinant virus. The isolation of recombinant viruses was greatly facilitated by the reduction of background "wild type" virus and the increased proportion of recombinant viruses. Since the recombinant viruses containing full-length and truncated forms of the crystal protein genes did not seem to improve the pathogenicity of the recombinant viruses when compared with the wild type AcNPV, and in order to compare expression levels of the full-length crystal proteins produced by non-occluded and occluded recombinant viruses the full-length cry1Ab and cry1Ac genes were chosen for construction of occluded recombinant viruses. The recombinant viruses containing full-length and truncated forms of the crystal protein genes did not seem to improve its pathogenicity but the size of the larvae infected with the recombinant viruses was significantly smaller than that of larvae infected with the wild type virus.
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Exploring proton transfer in 1,2,3-triazole-triazolium dimer with ab initio method
Li, Ailin; Yan, Tianying; Shen, Panwen
Ab initio calculations are utilized to search for transition state structures for proton transfer in the 1,2,3-triazole-triazolium complexes on the basis of optimized dimers. The result suggests six transition state structures for single proton transfer in the complexes, most of which are coplanar. The energy barriers, between different stable and transition states structures with zero point energy (ZPE) corrections, show that proton transfer occurs at room temperature with coplanar configuration that has the lowest energy. The results clearly support that reorientation gives triazole flexibility for proton transfer.
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Exploring proton transfer in 1,2,3-triazole-triazolium dimer with ab initio method
Energy Technology Data Exchange (ETDEWEB)
Li, Ailin; Yan, Tianying; Shen, Panwen [Department of Material Chemistry, Institute of New Energy Material Chemistry, Nankai University, Tianjin, 300071 (China)
2011-02-01
Ab initio calculations are utilized to search for transition state structures for proton transfer in the 1,2,3-triazole-triazolium complexes on the basis of optimized dimers. The result suggests six transition state structures for single proton transfer in the complexes, most of which are coplanar. The energy barriers, between different stable and transition states structures with zero point energy (ZPE) corrections, show that proton transfer occurs at room temperature with coplanar configuration that has the lowest energy. The results clearly support that reorientation gives triazole flexibility for proton transfer. (author)
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Remoroza, C.A.; Cord-Landwehr, S.; Leijdekkers, A.G.M.; Moerschbacher, B.M.; Schols, H.A.; Gruppen, H.
2012-01-01
The combined action of endo-polygalacturonase (endo-PGII), pectin lyase (PL), pectin methyl esterase (fungal PME) and RG-I degrading enzymes enabled the extended degradation of methylesterified and acetylated sugar beet pectins (SBPs). The released oligomers were separated, identified and quantified
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Supercritical fluid assisted production of chitosan oligomers micrometric powders.
Du, Zhe; Shen, Yu-Bin; Tang, Chuan; Guan, Yi-Xin; Yao, Shan-Jing; Zhu, Zi-Qiang
2014-02-15
Chitosan oligomers (O-chitosan) micrometric particles were produced from aqueous solution using a novel process, i.e. supercritical fluid assisted atomization introduced by hydrodynamic cavitation mixer (SAA-HCM). Hydrodynamic cavitation was introduced to enhance mass transfer and facilitate the mixing between SC-CO2 and liquid solution for fine particles formation. Well defined, separated and spherical microparticles were obtained, and the particles size could be well controlled with narrow distribution ranging from 0.5 μm to 3 μm. XRD patterns showed amorphous structure of O-chitosan microparticles. FTIR, TGA and DSC analyses confirmed that no change in molecular structure and thermal stability after SAA-HCM processing, while the water content was between 5.8% and 8.4%. Finally, tap densities were determined to be below 0.45 g/cm(3) indicating hollow or porous structures of microparticles. By tuning process parameters, theoretical mass median aerodynamic sizes lied inside respirable range of 1-2 μm, which presented the potential of the O-chitosan microparticles in application as inhaled dry powders. SAA-HCM was demonstrated to be very useful in particle size engineering. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Sankari, Siva; O'Brian, Mark R
2016-07-22
The bacterium Bradyrhizobium japonicum USDA110 does not synthesize siderophores for iron utilization in aerobic environments, and the mechanism of iron uptake within symbiotic soybean root nodules is unknown. An mbfA bfr double mutant defective in iron export and storage activities cannot grow aerobically in very high iron medium. Here, we found that this phenotype was suppressed by loss of function mutations in the feoAB operon encoding ferrous (Fe(2+)) iron uptake proteins. Expression of the feoAB operon genes was elevated under iron limitation, but mutants defective in either gene were unable to grow aerobically over a wide external ferric (Fe(3+)) iron (FeCl3) concentration range. Thus, FeoAB accommodates iron acquisition under iron limited and iron replete conditions. Incorporation of radiolabel from either (55)Fe(2+) or (59)Fe(3+) into cells was severely defective in the feoA and feoB strains, suggesting Fe(3+) reduction to Fe(2+) prior to traversal across the cytoplasmic membrane by FeoAB. The feoA or feoB deletion strains elicited small, ineffective nodules on soybean roots, containing few bacteria and lacking nitrogen fixation activity. A feoA(E40K) mutant contained partial iron uptake activity in culture that supported normal growth and established an effective symbiosis. The feoA(E40K) strain had partial iron uptake activity in situ within nodules and in isolated cells, indicating that FeoAB is the iron transporter in symbiosis. We conclude that FeoAB supports iron acquisition under limited conditions of soil and in the iron-rich environment of a symbiotic nodule. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.