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Sample records for 99tcm labeled cyclic

  1. Pharmacokinetics and radiation dosimetry of 99Tcm-labelled monoclonal antibody B43.13 in ovarian cancer patients.

    PubMed

    McQuarrie, S A; Baum, R P; Niesen, A; Madiyalakan, R; Korz, W; Sykes, T R; Sykes, C J; Hör, G; McEwan, A J; Noujaim, A A

    1997-09-01

    OVAREX MAb B43.13 is a new radiopharmaceutical based on a monoclonal antibody (MAb-B43.13) known to recognize CA 125, a tumour antigen associated with epithelial ovarian cancer. This MAb is capable of facile radiolabelling with 99Tcm and has been shown previously to localize in the tumours of ovarian cancer patients. The present study was initiated to measure the pharmacokinetics of this MAb in the serum of 10 patients with primary or metastatic ovarian cancer. A two-compartment model was found to be best at representing the biodistribution of the 99Tcm-labelled MAb, yielding a 2.6 h distribution phase half-life and a 31.3 h elimination phase half-life. The serum and renal clearances for 99Tcm-MAb-B43.13 were 121 and 53 ml h-1 respectively. These parameters were compared with a similar model developed from the serum values of the MAb itself (determined using an ELISA detection method). Based on the serum pharmacokinetics of 99Tcm-MAb-B43.13 and whole-body planar gamma camera images, an estimate of the radiation dose from 99Tcm was calculated using standard MIRD schema. The organs demonstrating significant 99Tcm uptake included the liver, kidneys, heart and spleen. The whole-body dose was similar to other 99Tcm-labelled MAbs.

  2. Beta decay of 99Tcm

    NASA Astrophysics Data System (ADS)

    Alburger, D. E.; Richards, P.; Ku, T. H.

    1980-02-01

    The emission of β rays from 6.02-h 99Tcm has been detected with an intermediate-image magnetic spectrometer. β-ray components with end-point energies of 434.8+/-2.6 keV (β0) to the 99Ru ground state and 346.7+/-2.0 keV (β1) to the 90-keV state were found with intensities per decay of (1.0+/-0.3) × 10-5 for β0 and (2.6+/-0.5) × 10-5 for β1. In the Kurie plot analysis the unique first-forbidden "α" shape was assumed for β0 and an allowed shape was assumed for β1. Values of f1t=9.39+/-0.11 for β0 and f0t=8.66+/-0.08 for β1 were derived. γ rays of 322, 233, and 140 keV were observed in a calibrated Ge(Li) detector with relative source intensities of I322:I233:I140=(1.13+/-0.09)×10-6:(0.95+/-0.17)×10-7:1.000. The total β-ray branching of 3.7 × 10-5 results in a negligible correction to dosage calculations in the use of 99Tcm for diagnostic nuclear medicine. RADIOACTIVITY 99Tcm: measured Eβ, Iβ, and Iγ magnetic spectrometer, Ge(Li); deduced decay scheme.

  3. A simple computer programme for biokinetic study of 99Tcm-radiopharmaceuticals.

    PubMed

    Imran, M B; Khurshid, S J; Anwar, K

    1994-02-01

    A simple programme has been written in GW BASIC to calculate the percentage activity of 99Tcm-radiopharmaceuticals in different tissues after biodistribution. The programme is efficient, easy to handle and produces a permanent record in terms of a final report.

  4. Is computer-aided interpretation of 99Tcm-HMPAO leukocyte scans better than the naked eye?

    PubMed

    Almer, S; Peters, A M; Ekberg, S; Franzén, L; Granerus, G; Ström, M

    1995-04-01

    In order to compare visual interpretation of inflammation detected by leukocyte scintigraphy with that of different computer-aided quantification methods, 34 patients (25 with ulcerative colitis and 9 with endoscopically verified non-inflamed colonic mucosa), were investigated using 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO) leukocyte scintigraphy and colonoscopy with biopsies. Scintigrams were obtained 45 min and 4 h after the injection of labelled cells. Computer-generated grading of seven colon segments using four different methods was performed on each scintigram for each patient. The same segments were graded independently using a 4-point visual scale. Endoscopic and histological inflammation were scored on 4-point scales. At 45 min, a positive correlation was found between endoscopic and scan gradings in individual colon segments when using visual grading and three of the four computer-aided methods (Spearman's rs = 0.30-0.64, P < 0.001). Histological grading correlated with visual grading and with two of the four computer-aided methods at 45 min (rs = 0.42-0.54, P < 0.001). At 4 h, all grading methods correlated positively with both endoscopic and histological assessment. The correlation coefficients were, in all but one instance, highest for the visual grading. As an inter-observer comparison to assess agreement between the visual gradings of two nuclear physicians, 14 additional patients (9 ulcerative colitis, 5 infectious enterocolitis) underwent leukocyte scintigraphy. Agreement assessed using kappa statistics was 0.54 at 45 min (P < 0.001). Separate data concerning the presence/absence of active inflammation showed a high kappa value (0.74, P < 0.001). Our results showed that a simple scintigraphic scoring system based on assessment using the human eye reflects colonic inflammation at least as well as computer-aided grading, and that highly correlated results can be achieved between different investigators.

  5. A simplified determination of glomerular filtration rate with 99Tcm-DTPA.

    PubMed

    Galli, G; Rufini, V; Meduri, G

    1994-10-01

    Using 99Tcm-diethylenetriaminepentaacetate (DTPA) an acceptable estimate of glomerular filtration rate (GFR) can be obtained in adult patients by the equation GF (ml/min) = (0.14 x W + 5) x 1000 x k, where W is the 'ideal' body mass (kg) and k the slope determined by two plasma samples. This has been verified in comparison with the results of the Russell (two samples) and Christensen (one sample) methods in 50 patients. The procedure, which does not require determination of the injected dose, could be useful in patients undergoing sequential renal scintigraphy with 99Tcm-DTPA, for example, to check a doubtful value of glomerular filtration obtained by external counting.

  6. An alternative method for rapid preparation of 99Tcm-sestamibi.

    PubMed

    Wilson, M E; Hung, J C; Gibbons, R J

    1993-07-01

    The availability of 99Tcm-sestamibi is limited, especially in emergency cases due to the time-consuming preparation procedure that requires a 10-min boiling water bath and a 30-min radiochemical purity (RCP) analysis. These two restrictions have been surmounted by the combined use of a microwave oven heating method and a minipaper chromatography system. However, use of the microwave oven heating method presents some potential problems: (1) technical error in setting the microwave oven heating time and power setting; (2) ejection of the rubber septum if the vial is not evacuated; (3) breakage of the vial during the microwave heating process; (4) inconsistent and inhomogeneous microwave heating; (5) reevaluation process required for use of a different type of microwave oven. Although a 1-min boiling water bath time is sufficient to provide an acceptable RCP for 99Tcm-sestamibi, additional time is required to heat the water to a boiling state. An instant hot water machine was evaluated for possible replacement of the microwave heating method. Three millilitres of 5500 MBq (150 mCi) 99Tcm was added to a Cardiolite kit and then placed in a 150-ml insulated beaker filled with hot water (86.2 +/- 1.9 degrees C, n = 45) from an instant hot water machine. A minipaper chromatography system was used to determine the RCP of samples after 1, 1.5, 2, 3, 4 and 5 min incubation periods. Our results show that 2 min was the shortest incubation time that yielded an acceptable RCP of 94.7 +/- 0.4% (n = 60) over the 24 h evaluation time. The use of an instant hot water machine not only avoids those problems associated with the microwave heating method, but also provides a rapid, efficient and relatively simple option for preparation of 99Tcm-sestamibi.

  7. Clinical Value of 99Tcm-MDP SPECT Bone Scintigraphy in the Diagnosis of Unilateral Condylar Hyperplasia

    PubMed Central

    Wen, Bing; Shen, Ying; Wang, Chang-Yin

    2014-01-01

    Purpose. To investigate the clinical value of 99Tcm-MDP SPECT for the diagnosis of unilateral condylar hyperplasia (UCH). Methods. One hundred forty-nine patients who underwent mandibular 99Tcm-MDP SPECT between January 2009 and December 2012 were studied, including 105 cases that were clinically suspected of UCH and 44 comparable cases without UCH as a control group. Results. Increased bone activity was observed in the affected condyles for all UCH patients. In the UCH group, the relative percentage uptake on the affected side was 59% (SD ± 4.3%), significantly higher than the 41% (SD ± 4.1%) uptake on the contralateral side (P<0.001). Similarly, the condyle/skull ratio was significantly higher for the affected side (1.66 ± 0.63) than for the contralateral side (1.34 ± 0.34, P < 0.01. No significant difference was found in the control group between the left and right condyles. Values for the sensitivity (95%), specificity (61%), positive (84.4%) and negative (84.6%) predictive values, and accuracy (84.5%) for 99Tcm-MDP SPECT in the diagnosis of UCH were calculated. However, for the hyperplastic condyle, no correlation was observed between the thickness of each cartilage layer and the relative uptake in the SPECT image. Conclusion. 99Tcm-MDP SPECT is accurate for diagnosing UCH and can provide a reference for treatment options. PMID:24901015

  8. An evaluation of 99Tcm-DMSA SPET with three-dimensional reconstruction in 68 patients with varied renal pathology.

    PubMed

    Cook, G J; Lewis, M K; Clarke, S E

    1995-11-01

    Sixty-eight patients (135 kidneys) with varied renal pathology were evaluated with 99Tcm-dimercaptosuccinic acid (DMSA) single photon emission tomography (SPET) to determine whether it is possible to detect more renal abnormalities and to reduce the number of false-positives due to anatomical variants when compared with planar imaging. The patients ranged in age from 1 to 78 years and their pathologies included urinary tract infection (n = 50), space occupying lesions (n = 5), calculi (n = 4), hypertension (n = 4) and others (n = 5). Planar scans were performed 3 h after the injection of 80 MBq of 99Tcm-DMSA and a 64 x 20 s acquisition over 360 degrees was used for SPET. High-resolution collimation was used for both. Slices were displayed as transaxial, coronal and sagittal and/or oblique sagittal in the plane of the kidney. Three-dimensional (3D) images were formed by volume rendering. Each kidney was divided into three regions and each region scored separately for the presence of an abnormality. Planar scans were reviewed alone and then in conjunction with SPET and 3D images. Planar imaging detected 95 abnormal regions compared with 103 using SPET. SPET reduced the number of equivocal regions in 8 (12%) patients. The diagnosis was altered by SPET in 17 (4%) regions in 14 (21%) patients. SPET and 3D 99Tcm-DMSA allow more abnormalities to be detected but also allow more specific definition of apparent abnormalities on planar imaging.

  9. Serial changes in regional blood flow in the cerebrum and cerebellum of stroke patients imaged by 99Tcm-HMPAO SPET.

    PubMed

    Lin, W Y; Kao, C H; Wang, P Y; Changlai, S P; Wang, S J

    1996-03-01

    Luxury perfusion is a well-known phenomenon that can mask ischaemic lesions in patients with cerebral infarction, thus making diagnosis difficult. In this study, we evaluated the incidence of luxury perfusion over a 3-week period following a stroke episode. The usefulness of crossed cerebellar diaschisis (CCD) as a complementary feature in the diagnosis of cerebral infarction was also evaluated using 99Tcm-hexamethylpropyleneamine oxime (99TcmHMPAO) brain single photon emission tomography (SPET). Twelve patients diagnosed as having a hemispheric ischaemic stroke of the middle cerebral arterial territory were enrolled in the study. Each patient underwent a total of four 99Tcm-HMPAO brain SPET examinations, 1 day, 1 week, 2 weeks and 3 weeks following the stroke episode. Our results show that the incidence of luxury perfusion was 67% (8/12) after 1 week, 75% (9/12) after 2 weeks and 83% (10/12) after 3 weeks. The incidence of CCD was 33% (4/12) after 1 day, 50% (6/12) after 1 week, 42% (5/12) after 2 weeks and 33% (4/12) after 3 weeks. We conclude that the detection of cerebral infarction is difficult 2 weeks or more after a stroke episode. The interval between the stroke episode and examination must be considered when reading the 99Tcm-HMPAO image. In addition, CCD may be helpful for the diagnosis of cerebral infarction within the first week after a stroke episode, especially in cases of an unidentified ischaemic region on the 99Tcm-HMPAO hemispheric image. However, the value of CCD is limited 2 weeks or more following the stroke episode.

  10. The absent kidney in 99Tcm-MAG3 renogram: a dramatic reversible consequence of contrast nephrotoxicity superimposed on renal obstruction.

    PubMed

    Kayani, I; Groves, A M; Syed, R; Nagabushan, N; Pakzad, F; Prvulovich, E M; Bomanji, J B

    2005-04-01

    99Tcm-mercaptoacetyltriglycine (MAG3) renogram is a robust imaging technique used to delineate upper urinary tract obstruction. The changes observed on the renogram are often reversible on relief of obstruction. We present two cases illustrating the extreme consequence of contrast nephrotoxicity on pre-existing obstructed kidneys. In one case, this led to severe impairment of perfusion and uptake observed on 99Tcm-MAG3 renogram and in the second case virtual non-visualization of the obstructed kidney. Subsequent treatment of obstruction, led to dramatic improvement in renal function. It is important for clinicians, nuclear medicine physicians and radiologists to be aware of the potential of contrast nephrotoxicity in obstructed kidneys.

  11. [Diagnostic value of MRI versus 99Tcm-MDP bone scan in osseous metastasis of prostate cancer: a meta-analysis].

    PubMed

    Shen, Guohua; Zhou, Luyi; Jia, Zhiyun; Zhang, Wenjie; Wang, Qiao; Deng, Houfu

    2014-08-01

    This paper is aimed to assess the diagnostic value of MRI versus 99 Tcm-methylene diphosphonate (99 Tcm- MDP) bone scan (BS) for osseous metastases in patients with prostate cancer. The computer-based retrieval was conducted on PubMed, EMBASE, EBSCO, Web of Knowledge, the Cochrane Library and Ovid data bases to search for trials about diagnosing osseous metastases of prostate cancer with MRI and 99Tc"m-MDP BS. Selected with time acceptance and time exclusion criteria, the data quality were evaluated with QUADAS quality assessment tool and collected. We used the Meta-Disc software to conduct meta-analysis, and then calculated the pooled sensitivity, specificity and diagnostic odds ratio (DOR), drew the summary receiving operating characteristic (SROC) curve, and measured the area under curve (AUC) and Q value. Then five studies were included, involving 353 patients. The pooled sensitivity of MRI and BS was 0. 95 (95% CI 0. 90~0. 98) and 0. 67 (95% CI 0. 58~0. 75), respectively. The pooled specificity was 0. 97 (95% CI 0. 94~0. 99) and 0. 88 (95% CI 0. 83~0. 91), respectively. The pooled DOR was 402.99 (95% CI 119. 05 ~1364. 15) and 23. 85 (95% CI 1. 32~431. 48), respectively. The AUC was 0. 990 1 and 0. 624 1, respectively. The Q was 0. 958 7 and 0. 593 8. It can well be concluded that MRI is more effective than 99 Tcm-MDP BS in the diagnosis of osseous metastases in patients with prostate cancer.

  12. 99Tcm-MIBI single photon emission tomography (SPET) for detecting myocardial ischaemia and necrosis in patients with significant coronary artery disease.

    PubMed

    Sciammarella, M G; Fragasso, G; Gerundini, P; Maffioli, L; Cappelletti, A; Margonato, A; Savi, A; Chierchia, S

    1992-12-01

    The ability of 99Tcm-methoxyisobutylisonitrile (MIBI) single photon emission tomography (SPET) to detect myocardial ischaemia and necrosis was assessed in 56 patients (45 male, 11 female, aged 55 +/- 5 years), with clinically recognized ischaemic heart disease (IHD). All underwent coronary angiography (CA) and left ventriculography (LV). SPET images were obtained at rest and at peak exercise (Modified Bruce) 90 min after injection of 99Tcm-MIBI (650-850 MBq). Data were acquired in 30 min over 180 degrees (from 45 degrees RAO to 45 degrees LPO) with no correction for attenuation, using a 64 x 64 matrix. The presence of persistent (P) or reversible (R) perfusion defects (PD) was then correlated to the resting and exercise ECG and to the results of CA and LV. Of the 56 patients, 34 had reversible underperfusion (RPD), 46 persistent underperfusion (PPD) and 31 had both. The occurrence of RPD correlated well with the occurrence of exercise-induced ST segment depression and/or angina (27 patients of 34 patients, 79%) and with the presence of significant coronary artery disease (CAD) (33 of 44, 73%). In 45 of 46 patients (98%) PPD corresponded to akinetic or severely hypokinetic segments (LV) usually explored by ECG leads exhibiting diagnostic Q waves (42 of 46 patients, 91%). The scan was normal both at rest and after stress in four of 11 patients with no CAD, and in two of 45 patients with CAD. Finally, an abnormal resting scan was seen in seven of 11 patients with normal coronary arteries, of whom six had regional wall motion abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Diselenide-Labeled Cyclic Polystyrene with Multiple Responses: Facile Synthesis, Tunable Size, and Topology.

    PubMed

    Cai, Zhaoxiong; Lu, Weihong; Gao, Feng; Pan, Xiangqiang; Zhu, Jian; Zhang, Zhengbiao; Zhu, Xiulin

    2016-05-01

    Diselenide-containing polymers have attracted more and more attention due to their redox sensitivity and bioapplication. In this work, a bifunctional diselenocarbonate is prepared and used to mediate the reversible addition-fragmentation chain transfer (RAFT) polymerization, producing α,ω-selenocarbonate-labeled telechelic polystyrene. Based on effective aminolysis of the terminal selenocarbonates and the followed spontaneous oxidation coupling reaction of diselenols, monoblock cyclic polystyrene linked by one diselenide bond and multiblock cyclic copolymer linked by several diselenide bonds are prepared by manipulating the concentration of α,ω-telechelic polystyrene in solution. The progress of aminolysis and the subsequent spontaneous oxidation of selenols to diselenides are monitored by UV-vis, gel permeation chromatography (GPC), and NMR characterizations, confirming the cyclic topologies of the resultant polymers (monocyclic or multiblock cyclic polymer). The monoblock cyclic or multiblock polymers show redox sensitivity, which can be converted to linear polymer by reducing or oxidizing agent. Moreover, the obtained monoblock cyclic polymer or multiblock cyclic copolymer can be transformed to each other under UV irradiation by adjusting the concentration of the cyclic polystyrene. For the first time, this work provides an alternative and promising approach to realize the topological transformation of polymers by installing multiresponsive diselenide moities into the backbone of cyclic polymer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. A nucleotide-independent cyclic nitroxide label for monitoring segmental motions in nucleic acids.

    PubMed

    Nguyen, Phuong H; Popova, Anna M; Hideg, Kálmán; Qin, Peter Z

    2015-01-01

    Spin labels, which are chemically stable radicals attached at specific sites of a bio-molecule, enable investigations on structure and dynamics of proteins and nucleic acids using techniques such as site-directed spin labeling and paramagnetic NMR. Among spin labels developed, the class of rigid labels have limited or no independent motions between the radical bearing moiety and the target, and afford a number of advantages in measuring distances and monitoring local dynamics within the parent bio-molecule. However, a general method for attaching a rigid label to nucleic acids in a nucleotide-independent manner has not been reported. We developed an approach for installing a nearly rigid nitroxide spin label, designated as R5c, at a specific site of the nucleic acid backbone in a nucleotide-independent manner. The method uses a post-synthesis approach to covalently attach the nitroxide moiety in a cyclic fashion to phosphorothioate groups introduced at two consecutive nucleotides of the target strand. R5c-labeled nucleic acids are capable of pairing with their respective complementary strands, and the cyclic nature of R5c attachment significantly reduced independence motions of the label with respect to the parent duplex, although it may cause distortion of the local environment at the site of labeling. R5c yields enhanced sensitivity to the collective motions of the duplex, as demonstrated by its capability to reveal changes in collective motions of the substrate recognition duplex of the 120-kDa Tetrahymena group I ribozyme, which elude detection by a flexible label. The cyclic R5c nitroxide can be efficiently attached to a target nucleic acid site using a post-synthetic coupling approach conducted under mild biochemical conditions, and serves as a viable label for experimental investigation of segmental motions in nucleic acids, including large folded RNAs.

  15. A Trp-BODIPY cyclic peptide for fluorescence labelling of apoptotic bodies.

    PubMed

    Subiros-Funosas, Ramon; Mendive-Tapia, Lorena; Sot, Jesus; Pound, John D; Barth, Nicole; Varela, Yaiza; Goñi, Felix M; Paterson, Margaret; Gregory, Christopher D; Albericio, Fernando; Dransfield, Ian; Lavilla, Rodolfo; Vendrell, Marc

    2017-01-10

    The rational design and synthesis of a Trp-BODIPY cyclic peptide for the fluorescent labelling of apoptotic bodies is described. Affinity assays, confocal microscopy and flow cytometry analysis confirmed the binding of the peptide to negatively-charged phospholipids associated with apoptosis, and its applicability for the detection and characterisation of subcellular structures released by apoptotic cells.

  16. Labels, cognomes, and cyclic computation: an ethological perspective

    PubMed Central

    Murphy, Elliot

    2015-01-01

    For the past two decades, it has widely been assumed by linguists that there is a single computational operation, Merge, which is unique to language, distinguishing it from other cognitive domains. The intention of this paper is to progress the discussion of language evolution in two ways: (i) survey what the ethological record reveals about the uniqueness of the human computational system, and (ii) explore how syntactic theories account for what ethology may determine to be human-specific. It is shown that the operation Label, not Merge, constitutes the evolutionary novelty which distinguishes human language from non-human computational systems; a proposal lending weight to a Weak Continuity Hypothesis and leading to the formation of what is termed Computational Ethology. Some directions for future ethological research are suggested. PMID:26089809

  17. The use of 99Tcm-DTPA aerosol and caesium iodide mini-scintillation detectors in the assessment of lung injury during cardiopulmonary bypass surgery.

    PubMed

    Keavey, P M; Hasan, A; Au, J; Dark, J H

    1997-01-01

    Lung injury is a well-documented adverse effect of cardiopulmonary bypass. The mechanism of injury is not fully understood, but pulmonary hypoxia may be a factor. Post-operative pulmonary epithelial permeability (PEP) in ventilated versus non-ventilated lungs was measured within 2 h of return to the intensive care unit using a 99Tcm-diethylenetriamine pentaacetate aerosol technique. A portable scintillation detector system was required. Sodium iodide detectors have been used previously with this technique but are cumbersome. This study used mini caesium iodide detectors (Oakfield Instruments, Oxon, UK), which can be attached directly to the patient and are more suited to the intensive care setting. The clearance half-time from lung to blood (T1/2LB) was measured in 31 patients (62 lungs). The mean (+/- S.E.M.) clearance half-times were 42.3 +/- 2.7 and 45.7 +/- 3.8 min for non-ventilated and ventilated lungs respectively, with a mean difference of 3.4 +/- 3.1 min (P > 0.05). We conclude that, using this technique, no significant difference in PEP is observed between ventilated and non-ventilated lungs in patients undergoing cardiopulmonary bypass.

  18. Stress/injection protocols for myocardial scintigraphy with 99Tcm-sestamibi compared with 201Tl: implications of early post-stress kinetics.

    PubMed

    Hurwitz, G A; Blais, M; Powe, J E; Champagne, C L

    1996-05-01

    Stress/injection protocols developed for myocardial perfusion imaging with 201Tl may not be optimal for 99Tcm-sestamibi (MIBI), an agent with lower myocardial extraction and higher abdominal uptake; prolongation of exercise after radiotracer injection might improve these relative drawbacks of MIBI. We compared the kinetics of MIBI and 201Tl by acquiring dynamic planar images for 5-7 min after a bolus injection (n = 180 studies) with stress performed by supine bicycle exercise alone, intravenous dipyridamole or combined stress. Routine or prolonged protocols involved continuation of exercise for 1 or 2.5 min respectively after tracer appearance in the heart. Subsequently, the perfusion images obtained were categorized as normal or showing significant defects. Myocardial uptake of MIBI, normalized for injected dose, body weight and camera sensitivity, was only 40% of that for 201Tl; there were no differences based on test mode or scan result for either perfusion tracer. During the second minute after injection, the cavity/myocardial ratios, an index of blood pool activity, were elevated with MIBI by 25% when compared with 201Tl (P < 0.001). During the third minute, cavity activity was again higher with MIBI, but only in those subjects with abnormal scans. The prolonged exercise phase did not prevent progressive accumulation in the abdomen, but did allow cavity levels to decline before termination of exercise. The prolonged protocol may ensure that myocardial uptake of MIBI is completed during peak blood flow, and therefore is recommended for stress with exercise or with dipyridamole and exercise in combination.

  19. The importance of 99Tcm-DMSA renal scintigraphy in the follow-up of acute pyelonephritis in children: comparison with urographic data.

    PubMed

    Lavocat, M P; Granjon, D; Guimpied, Y; Dutour, N; Allard, D; Prevôt, N; Dubois, F

    1998-07-01

    At present, 99Tcm-dimercaptosuccinic acid (DMSA) renal scintigraphy is the most sensitive examination for the detection of parenchymal damage during acute pyelonephritis (APN) in children. This prospective study had three aims: (1) to evaluate the medium-term evolution of the scintigraphic abnormalities, to find a prognostic criterion of scintigraphic evolution; (2) to assess the correlation between the severity of early or late scintigraphic damage and selected clinical factors; and (3) to compare the permanent scintigraphic renal scars with intravenous urography (IVU) 2 years after the acute infection. Seventy-four children (mean age 32 months), presenting with a first clinical episode of pyelonephritis and an initial scintigraphic abnormality, were included in the study. Patients with a history of urinary tract infection (UTI), uropathy other than vesico-ureteral reflux (VUR) and a relapse of acute pyelonephritis were excluded. All children underwent control scintigraphy (mean 9 months after APN) and 43 had an IVU (mean 26 months after APN). Fifty-seven children (77%) still have scintigraphic abnormalities of varying severity (7 atrophic kidneys). Initial relative DMSA uptake of less than 45% results in a worse scintigraphic prognosis. The age of the child has no bearing on the severity of the initial renal involvement or on the evolution of the scintigraphic abnormalities. The rapid introduction of antibiotics (< 12 h) significantly improves the scintigraphic prognosis (P < 0.01). The presence of reflux (n = 39) leads to more serious initial damage, but we did not find any effect on later evolution in this study, in which all reflux was low grade in nature. Among the 43 children who had an IVU, 5 showed typical urographic and scintigraphic renal scars in the corresponding region and 38 showed a normal IVU with 28 cases of scintigraphic abnormalities. A DMSA scan is more sensitive than IVU for the detection of renal scarring after a first episode of APN.

  20. Synchrotron X-ray fluorescence studies of a bromine-labelled cyclic RGD peptide interacting with individual tumor cells

    PubMed Central

    Sheridan, Erin J.; Austin, Christopher J. D.; Aitken, Jade B.; Vogt, Stefan; Jolliffe, Katrina A.; Harris, Hugh H.; Rendina, Louis M.

    2013-01-01

    The first example of synchrotron X-ray fluorescence imaging of cultured mammalian cells in cyclic peptide research is reported. The study reports the first quantitative analysis of the incorporation of a bromine-labelled cyclic RGD peptide and its effects on the biodistribution of endogenous elements (for example, K and Cl) within individual tumor cells. PMID:23412478

  1. Synchrotron X-ray fluorescence studies of a bromine-labelled cyclic RGD peptide interacting with individual tumor cells.

    PubMed

    Sheridan, Erin J; Austin, Christopher J D; Aitken, Jade B; Vogt, Stefan; Jolliffe, Katrina A; Harris, Hugh H; Rendina, Louis M

    2013-03-01

    The first example of synchrotron X-ray fluorescence imaging of cultured mammalian cells in cyclic peptide research is reported. The study reports the first quantitative analysis of the incorporation of a bromine-labelled cyclic RGD peptide and its effects on the biodistribution of endogenous elements (for example, K and Cl) within individual tumor cells.

  2. Radiolabeling, stability studies, and pharmacokinetic evaluation of thulium-170-labeled acyclic and cyclic polyaminopolyphosphonic acids.

    PubMed

    Vats, Kusum; Das, Tapas; Sarma, Haladhar D; Banerjee, Sharmila; Pillai, M R A

    2013-12-01

    Thulium-170 [T1/2=128.4 days, Eβ(max)=968 keV, and Eγ=84 keV (3.26%)] could be considered an easily producible and cost-effective alternative to (89)Sr for the preparation of radiopharmaceuticals for palliation of bone pain arising due to skeletal metastases. Multidentate aminomethylene polyphosphonic acids have already been proven to be effective as carrier moieties for developing radiolabeled bone pain palliation agents using lanthanide radionuclides. Therefore, an attempt was made to evaluate the potential of a series of (170)Tm-labeled acyclic (diethylenetriaminepentamethylene phosphonic acid and triethylenetetraminehexamethylene phosphonic acid) and cyclic polyaminopolyphosphonic acids (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene phosphonic acid [DOTMP] and 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetramethylene phosphonic acid [CTMP]) toward their use as alternative bone pain palliation agents. Thulium-170 was produced by irradiating the natural Tm2O3 target at a thermal neutron flux of 7×10(13) n·cm(-2)·s(-1) for a period of 60 days. All the phosphonic acid ligands were synthesized and characterized in-house. The protocols for radiolabeling the phosphonic acids with (170)Tm were standardized. Biological evaluation of the (170)Tm-labeled phosphonic acids were carried out in normal Wistar rats by biodistribution as well as by scintigraphic studies. Thulium-170 was produced with adequate specific activity (173 Ci/g, 6.41 TBq/g) and high radionuclidic purity (99.62%). All the (170)Tm-labeled phosphonic acids, except (170)Tm-CTMP, were prepared with very high radiochemical purity (>98%) under optimized reaction conditions and exhibited high stability. All the agents showed selective skeletal accumulation with insignificant uptake in other vital organs/tissues and major clearance through renal pathway. These findings were also substantiated by scintigraphic studies. Although all the (170)Tm-labeled phosphonic acids showed significant and

  3. Effect of cyclic, low dose pyrimethamine treatment in patients with Late Onset Tay Sachs: an open label, extended pilot study.

    PubMed

    Osher, Etty; Fattal-Valevski, Aviva; Sagie, Liora; Urshanski, Nataly; Sagiv, Nadav; Peleg, Leah; Lerman-Sagie, Tally; Zimran, Ari; Elstein, Deborah; Navon, Ruth; Valevski, Avi; Stern, Naftali

    2015-04-17

    Late Onset Tay- Sachs disease (LOTS) is a rare neurodegenerative lysosomal storage disease which results from mutations in the gene encoding the α subunit (HEXA) of β-hexosaminidase enzyme (HexA). At the present time, no effective treatment exists for LOTS and other neurodegenerative diseases involving the central nerve system (CNS). Pyrimethamine (PMT) was previously shown to act as a HexA chaperone in human fibroblasts in vitro carrying some (e.g., αG269S), but not all LOTS-related mutations. The present study assessed the effect of cyclic, low dose and long term pyrimethamine treatment on HexA in subjects with LOTS. In an open label trial in 4 LOTS patients, PMT was initiated at an average daily dose of ~2.7 mg and administered cyclically guided by blood lymphocyte HexA activity for a mean duration of 82.8 (±22.5; SD) weeks (~1.5 year). HexA activity rose in all subjects, with a mean peak increase of 2.24 folds (±0.52; SD) over baseline activity (range 1.87-3). The mean treatment time required to attain this peak was of 15.7 (±4.8; SD) weeks. Following increase in activity, HexA gradually declined with the continued use of PMT, which was then stopped, resulting in the return of HexA activity to baseline. A second cycle of PMT treatment was then initiated, resulting again in an increase in HexA activity. Three of the patients experienced a measurable neuropsychiatric deterioration whereas one subject remained entirely stable. Cyclic low dose of PMT can increase HexA activity in LOTS patients. However, the observed increase is repeatedly transient and not associated with discernible beneficial neurological or psychiatric effects.

  4. A fluorophore-labelled copper complex: crystal structure, hybrid cyclic water-perchlorate cluster and biological properties.

    PubMed

    Bhat, Satish S; Revankar, Vidyanand K; Shivalingegowda, Naveen; Lokanath, N K

    2017-09-01

    A fluorophore-labelled copper(II) complex, aquabis(dimethylformamide-κO)(perchlorato-κO)[2-(quinolin-2-yl)-1,3-oxazolo[4,5-f][1,10]phenanthroline]copper(II) perchlorate monohydrate, [Cu(ClO4)(C22H12N4O)(C3H7NO)2(H2O)]ClO4·H2O, has been synthesized and characterized. A cyclic hydrogen-bonded water-perchlorate anionic cluster, i.e. [(ClO4)2(H2O)2](2-), has been identified within the structure. Each cyclic anionic cluster unit is interconnected by hydrogen bonding to the cation. The cations join into an infinite hydrogen-bonded chain running in the [010] direction. Furthermore, interaction of the complex with calf-thymus DNA (CT-DNA) and cellular localization within the cells was explored. Spectroscopic studies indicate that the compound has a good affinity for DNA and stains the nucleus of the cells.

  5. An assessment tumor targeting ability of (177)Lu labeled cyclic CCK analogue peptide by binding with cholecystokinin receptor.

    PubMed

    Cho, Eun-Ha; Lim, Jae Cheong; Lee, So-Young; Jung, Sung-Hee

    2016-07-01

    The cholecystokinin (CCK) receptor is known as a receptor that is overexpressed in many human tumors. The present study was designed to investigate the targeting ability of cyclic CCK analogue in AR42J pancreatic cells. The CCK analogues, DOTA-K(glucose)-Gly-Trp-Nle-Asp-Phe (DOTA-glucose-CCK) and DOTA-Nle-cyclo(Glu-Trp-Nle-Asp-Phe-Lys-NH2) (DOTA-[Nle]-cCCK), were synthesized and radiolabeled with (177)Lu, and competitive binding was evaluated. The binding appearance of synthesized peptide with AR42J cells was evaluated by confocal microscopy. And bio-distribution was performed in AR42J xenografted mice. Synthesized peptides were prepared by a solid phase synthesis method, and their purity was over 98%. DOTA is the chelating agent for (177)Lu-labeling, in which the peptides were radiolabeled with (177)Lu by a high radiolabeling yield. A competitive displacement of (125)I-CCK8 on the AR42J cells revealed that the 50% inhibitory concentration value (IC50) was 12.3 nM of DOTA-glucose-CCK and 1.7 nM of DOTA-[Nle]-cCCK. Radio-labeled peptides were accumulated in AR42J tumor in vivo, and %ID/g of the tumor was 0.4 and 0.9 at 2 h p.i. It was concluded that (177)Lu-DOTA-[Nle]-cCCK has higher binding affinity than (177)Lu-DOTA-glucose-CCK and can be a potential candidate as a targeting modality for a CCK receptor over-expressing tumors. Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  6. Linker effects on biological properties of 111In-labeled DTPA conjugates of a cyclic RGDfK dimer.

    PubMed

    Jia, Bing; Liu, Zhaofei; Shi, Jiyun; Yu, Zilin; Yang, Zhi; Zhao, Huiyun; He, Zhengjie; Liu, Shuang; Wang, Fan

    2008-01-01

    In this report, we present in vitro and in vivo evaluation of three 111 In-labeled DTPA conjugates of a cyclic RGDfK dimer: DTPA-Bn-SU016 (SU016 = E[c(RGDfK)] 2; DTPA-Bn = 2-( p-isothioureidobenzyl)diethylenetriaminepentaacetic acid), DTPA-Bn-E-SU016 ( E = glutamic acid) and DTPA-Bn-Cys-SU016 (Cys = cysteic acid). The integrin alpha vbeta 3 binding affinities of SU016, DTPA-Bn-SU016, DTPA-Bn-E-SU016, and DTPA-Bn-Cys-SU016 were determined to be 5.0 +/- 0.7 nM, 7.9 +/- 0.6 nM, 5.8 +/- 0.6 nM, and 6.9 +/- 0.9 nM, respectively, against 125 I-c(RGDyK) in binding to integrin alpha vbeta3, suggesting that E or Cys residue has little effect on the integrin alpha vbeta3 affinity of E[c(RGDfK)] 2. It was also found that the 111 In-labeling efficiency of DTPA-Bn-SU016 and DTPA-Bn-E-SU016 is 3-5 times better than that of DOTA analogues due to fast chelation kinetics and high-yield 111 In-labeling under mild conditions (e.g., room temperature). Biodistribution studies were performed using BALB/c nude mice bearing U87MG human glioma xenografts. 111 In-DTPA-Bn-SU016, 111 In-DTPA-Bn-E-SU016, and 111 In-DTPA-Bn-Cys-SU016 all displayed rapid blood clearance. Their tumor uptake was comparable between 0.5 and 4 h postinjection (p.i.) within experimental error. 111 In-DTPA-Bn-E-SU016 had a significantly lower ( p < 0.01) kidney uptake than 111 In-DTPA-Bn-SU016 and 111 In-DTPA-Bn-Cys-SU016. The liver uptake of 111 In-DTPA-Bn-SU016 was 1.69 +/- 0.18% ID/g at 24 h p.i., while the liver uptake values of 111 In-DTPA-Bn-E-SU016 and 111 In-DTPA-Bn-Cys-SU016 were 0.55 +/- 0.11% ID/g and 0.79 +/- 0.15% ID/g at 24 h p.i., respectively. Among the three 111 In radiotracers evaluated in this study, 111 In-DTPA-Bn-E-SU016 has the lowest liver and kidney uptake and the best tumor/liver and tumor/kidney ratios. Results from metabolism studies indicated that there is little metabolism (<10%) for three 111 In radiotracers at 1 h p.i. Imaging data showed that tumors can be clearly visualized at 4 h p

  7. Linker Effects on Biological Properties of 111In-Labeled DTPA Conjugates of a Cyclic RGDfK Dimer

    PubMed Central

    Jia, Bing; Liu, Zhaofei; Shi, Jiyun; Yu, Zilin; Yang, Zhi; Zhao, Huiyun; He, Zhengjie; Liu, Shuang; Wang, Fan

    2008-01-01

    In this report, we present in vitro and in vivo evaluation of three 111In-labeled DTPA conjugates of a cyclic RGDfK dimer: DTPA-Bn-SU016 (SU016 = E[c(RGDfK)]2; DTPA-Bn = 2-(p-isothiocyanobenzyl)diethylenetriaminepentaacetic acid), DTPA-Bn-E-SU016 (E = glutamic acid) and DTPA-Bn-Cys-SU016 (Cys = cysteic acid). The integrin αvβ3 binding affinities of SU016, DTPA-Bn-SU016, DTPA-Bn-E-SU016 and DTPA-Bn-Cys-SU016 were determined to be 5.0 ± 0.7 nM, 7.9 ± 0.6 nM, 5.8 ± 0.6 nM and 6.9 ± 0.9 nM, respectively, against 125I-c(RGDyK) in binding to integrin αvβ3, suggesting that E or Cys residue has little effect on the integrin αvβ3 affinity of E[c(RGDfK)]2. It was also found that the 111In-labeling efficiency of DTPA-Bn-SU016 and DTPA-Bn-E-SU016 is 3–5 times better than that of DOTA analogs due to fast chelation kinetics and high-yield 111In-labeling under mild conditions (e.g. room temperature). Biodistribution studies were performed using BALB/c nude mice bearing U87MG human glioma xenografts. 111In-DTPA-Bn-SU016, 111In-DTPA-Bn-E-SU016 and 111In-DTPA-Bn-Cys-SU016 all displayed a rapid blood clearance. Their tumor uptake was comparable between 0.5 h and 4 h postinjection (p.i.) within experimental error. 111In-DTPA-Bn-E-SU016 had a significantly lower (p < 0.01) kidney uptake than 111In-DTPA-Bn-SU016 and 111In-DTPA-Bn-Cys-SU016. The liver uptake of 111In-DTPA-Bn-SU016 was 1.69 ± 0.18 %ID/g at 24 h p.i. while the liver uptake of 111In-DTPA-Bn-E-SU016 and 111In-DTPA-Bn-Cys-SU016 was 0.55 ± 0.11 %ID/g and 0.79 ± 0.15 %ID/g at 24 h p.i., respectively. Among the three 111In radiotracers evaluated in this study, 111In-DTPA-Bn-E-SU016 has the lowest liver and kidney uptake and the best tumor/liver and tumor/kidney ratios. Results from metabolism studies indicated that there is little (<10%) metabolism for three 111In radiotracers at 1 h p.i. Imaging data showed that tumors can be clearly visualized at 4 h p.i. with good contrast in the tumor-bearing mice administered

  8. Evaluation of 99mTc-labeled cyclic RGD dimers: impact of cyclic RGD peptides and 99mTc chelates on biological properties.

    PubMed

    Zhou, Yang; Kim, Young-Seung; Lu, Xin; Liu, Shuang

    2012-03-21

    The main objective of this study is to explore the impact of cyclic RGD peptides and (99m)Tc chelates on biological properties of (99m)Tc radiotracers. Cyclic RGD peptide conjugates, HYNIC-K(NIC)-RGD(2) (HYNIC = 6-hydrazinonicotinyl; RGD(2) = E[c(RGDfK)](2) and NIC = nicotinyl), HYNIC-K(NIC)-3G-RGD(2) (3G-RGD(2) = Gly-Gly-Gly-E[Gly-Gly-Gly-c(RGDfK)](2)), and HYNIC-K(NIC)-3P-RGD(2) (3P-RGD(2) = PEG(4)-E[PEG(4)-c(RGDfK)](2)), were prepared. Macrocyclic (99m)Tc complexes [(99m)Tc(HYNIC-K(NIC)-RGD(2))(tricine)] (1), [(99m)Tc(HYNIC-K(NIC)-3G-RGD(2))(tricine)] (2), and [(99m)Tc(HYNIC-K(NIC)-3P-RGD(2))(tricine)] (3) were evaluated for their biodistribution and tumor-targeting capability in athymic nude mice bearing MDA-MB-435 human breast tumor xenografts. It was found that 1, 2, and 3 could be prepared with high specific activity (∼111 GBq/μmol). All three (99m)Tc radiotracers have two major isomers, which show almost identical uptake in tumors and normal organs. Replacing the bulky and highly charged [(99m)Tc(HYNIC)(tricine)(TPPTS)] (TPPTS = trisodium triphenylphosphine-3,3',3″-trisulfonate) with a smaller [(99m)Tc(HYNIC-K(NIC))(tricine)] resulted in less uptake in the kidneys and lungs for 3. Surprisingly, all three (99m)Tc radiotracers shared a similar tumor uptake (1, 5.73 ± 0.40%ID/g; 2, 5.24 ± 1.09%ID/g; and 3, 4.94 ± 1.71%ID/g) at 60 min p.i. The metabolic stability of (99m)Tc radiotracers depends on cyclic RGD peptides (3P-RGD(2) > 3G-RGD(2) ∼ RGD(2)) and (99m)Tc chelates ([(99m)Tc(HYNIC)(tricine)(TPPTS)] > [(99m)Tc(HYNIC-K(NIC))(tricine)]). Immunohistochemical studies revealed a linear relationship between the α(v)β(3) expression levels and tumor uptake or tumor/muscle ratios of 3, suggesting that 3 is useful for monitoring the tumor α(v)β(3) expression. Complex 3 is a very attractive radiotracer for detection of integrin α(v)β(3)-positive tumors.

  9. A label-free and self-assembled electrochemical biosensor for highly sensitive detection of cyclic diguanylate monophosphate (c-di-GMP) based on RNA riboswitch.

    PubMed

    Xie, Qingyun; Zhao, Fulin; Liu, Hongrui; Shan, Yanke; Liu, Fei

    2015-07-02

    Cyclic diguanylate monophosphate (c-di-GMP) is an important second messenger that regulates a variety of complex physiological processes involved in motility, virulence, biofilm formation and cell cycle progression in several bacteria. Herein we report a simple label-free and self-assembled RNA riboswitch-based biosensor for sensitive and selective detection of c-di-GMP. The detectable concentration range of c-di-GMP is from 50 nM to 1 μM with a detection limit of 50 nM. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. (68)Ga-labeled cyclic RGD dimers with Gly3 and PEG4 linkers: promising agents for tumor integrin alphavbeta3 PET imaging.

    PubMed

    Liu, Zhaofei; Niu, Gang; Shi, Jiyun; Liu, Shuanglong; Wang, Fan; Liu, Shuang; Chen, Xiaoyuan

    2009-06-01

    Radiolabeled cyclic RGD (Arg-Gly-Asp) peptides have great potential for the early tumor detection and noninvasive monitoring of tumor metastasis and therapeutic response. (18)F-labeled RGD analogs ([(18)F]-AH111585 and [(18)F]Galacto-RGD) have been investigated in clinical trials for positron emission tomography (PET) imaging of integrin expression in cancer patients. To develop new RGD radiotracers with higher tumor accumulation, improved in vivo kinetics, easy availability and low cost, we developed two new RGD peptides and labeled them with generator-eluted (68)Ga (t(1/2) = 68 min) for PET imaging of integrin alpha(v)beta(3) expression in tumor xenograft models. The two new cyclic RGD dimers, E[PEG(4)-c(RGDfK)](2) (P(4)-RGD2, PEG(4) = 15-amino-4,7,10,13-tetraoxapentadecanoic acid) and E[Gly(3)-c(RGDfK)](2) (G(3)-RGD2, G(3) = Gly-Gly-Gly) were designed, synthesized and conjugated with 1,4,7-triazacyclononanetriacetic acid (NOTA) for (68)Ga labeling. The microPET imaging and biodistribution of the (68)Ga labeled RGD tracers were investigated in integrin alpha(v)beta(3)-positive tumor xenografts. The new RGD dimers with the Gly(3) and PEG(4) linkers showed higher integrin alpha(v)beta(3) binding affinity than no-linker RGD dimer (RGD2). NOTA-G(3)-RGD2 and NOTA-P(4)-RGD2 could be labeled with (68)Ga within 30 min with higher purity (>98%) and specific activity (8.88-11.84 MBq/nmol). Both (68)Ga-NOTA-P(4)-RGD2 and (68)Ga-NOTA-G(3)-RGD2 exhibited significantly higher tumor uptake and tumor-to-normal tissue ratios than (68)Ga-NOTA-RGD2. Because of their high affinity, high specificity and excellent pharmacokinetic properties, further investigation of the two novel RGD dimers for clinical PET imaging of integrin alpha(v)beta(3) expression in cancer patients is warranted.

  11. A label-free and high-efficient GO-based aptasensor for cancer cells based on cyclic enzymatic signal amplification.

    PubMed

    Xiao, Kunyi; Liu, Juan; Chen, Hui; Zhang, Song; Kong, Jilie

    2017-05-15

    A label-free and high-efficient graphene oxide (GO)-based aptasensor was developed for the detection of low quantity cancer cells based on cell-triggered cyclic enzymatic signal amplification (CTCESA). In the absence of target cells, hairpin aptamer probes (HAPs) and dye-labeled linker DNAs stably coexisted in solution, and the fluorescence was quenched by the GO-based FÖrster resonance energy transfer (FRET) process. In the presence of target cells, the specific binding of HAPs with the target cells triggered a conformational alternation, which resulted in linker DNA complementary pairing and cleavage by nicking endonuclease-strand scission cycles. Consequently, more cleaved fragments of linker DNAs with more the terminal labeled dyes could show the enhanced fluorescence because these cleaved DNA fragments hardly combine with GOs and prevent the FRET process. Fluorescence analysis demonstrated that this GO-based aptasensor exhibited selective and sensitive response to the presence of target CCRF-CEM cells in the concentration range from 50 to 10(5) cells. The detection limit of this method was 25 cells, which was approximately 20 times lower than the detection limit of normal fluorescence aptasensors without amplification. With high sensitivity and specificity, it provided a simple and cost-effective approach for early cancer diagnosis.

  12. Sulfonation of Tyrosine as a Method to Improve Biodistribution of Peptide-Based Radiotracers: Novel (18)F-Labelled Cyclic RGD Analogues.

    PubMed

    Haskali, Mohammad Baqir; Denoyer, Delphine; Noonan, Wayne; Cullinane, Carleen; Rangger, Christine; Pouliot, Normand; Haubner, Roland; Roselt, Peter D; Hicks, Rodney J; Hutton, Craig A

    2017-02-13

    The labeling of peptides with positron emitting radionuclides has long held the promise of a wide range of PET agents possessing high affinity and selectivity. Not surprisingly, controlling the biodistribution of these agents has proven to be a major challenge in their successful application. Modification of peptide hydrophilicity in order to increase renal clearance has been a common endeavor to improve overall biodistribution. Herein, we examine the effect of site-specific sulfonation of tyrosine moieties in cyclic(RGDyK) peptides as a means to enhance their hydrophilicity and improve their biodistribution. The novel sulfonated cyclic(RGDyK) peptides were conjugated directly to 4-nitrophenyl 2-[18F]fluoropropionate and the biodistribution of the radiolabeled peptides was compared with that of their non-sulfonated, clinically relevant counterparts, [18F]GalactoRGD and [18F]FPPRGD2. Site-specific sulfonation of the tyrosine residues was shown to increase hydrophilicity and improve biodistribution of the RGD peptides, despite contributing just 79 Da towards the MW, compared with 189 Da for both the 'Galacto' and mini-PEG moieties, suggesting this may be a broadly applicable approach to enhancing biodistribution of radiolabelled peptides.

  13. Impact of Multiple Negative Charges on Blood Clearance and Biodistribution Characteristics of 99mTc-Labeled Dimeric Cyclic RGD Peptides

    PubMed Central

    2015-01-01

    the multiple negative charges have a significant impact on the blood clearance kinetics and tumor uptake of 99mTc-labeled dimeric cyclic RGD peptides. PMID:25144854

  14. On-resin synthesis of an acylated and fluorescence-labeled cyclic integrin ligand for modification of poly(lactic-co-glycolic acid).

    PubMed

    Hassert, Rayk; Hoffmeister, Peter-Georg; Pagel, Mareen; Hacker, Michael; Schulz-Siegmund, Michaela; Beck-Sickinger, Annette G

    2012-11-01

    Cyclic Arg-Gly-Asp (RGD) peptides show remarkable affinity and specificity to integrin receptors and mediate important physiological effects in tumor angiogenesis. Additionally, they are one of the keyplayers in improving the biocompatibility of biomaterials. The fully biodegradable polymer poly(lactic-co-glycolic acid) (PLGA) is frequently used for biomedical implants and can be applied as nanoparticles for drug delivery. The aim of this work was the generation of a lipidated c[RGDfK] peptide including a second functionality for coating of hydrophobic PLGA. Therefore, we established a general and straightforward strategy for the introduction of two different modifications into the same c[RGDfK] peptide. This allowed the generation of a palmitoylated integrin-binding lipopeptide that shows high affinity to PLGA. Additionally, we coupled 5(6)-carboxyfluorescein to the second site for modification to enable sensitive quantification of the immobilized lipopeptide on PLGA. In conclusion, we present a synthesis protocol that enables the preparation of c[RGDfK] lipopeptides with a strong affinity to PLGA and an additional site for modifications. This will provide the opportunity to introduce a variety of effector molecules site-specifically to the c[RGDfK] lipopeptide, which will enable the introduction of multifunctionality into c[RGDfK]-coated PLGA devices or nanoparticles.

  15. Cyclic Voltammetry.

    ERIC Educational Resources Information Center

    Evans, Dennis H.; And Others

    1983-01-01

    Cyclic voltammetry is a simple experiment that has become popular in chemical research because it can provide useful information about redox reactions in a form which is easily obtained and interpreted. Discusses principles of the method and illustrates its use in the study of four electrode reactions. (Author/JN)

  16. Cyclic Voltammetry.

    ERIC Educational Resources Information Center

    Evans, Dennis H.; And Others

    1983-01-01

    Cyclic voltammetry is a simple experiment that has become popular in chemical research because it can provide useful information about redox reactions in a form which is easily obtained and interpreted. Discusses principles of the method and illustrates its use in the study of four electrode reactions. (Author/JN)

  17. Cyclic-AMP-dependent protein kinase (PKA) activity assay based on FRET between cationic conjugated polymer and chromophore-labeled peptide.

    PubMed

    Tang, Shiyun; Hu, Yufang; Shen, Qinpeng; Fang, Heting; Li, Wang; Nie, Zhou; Yao, Shouzhuo

    2014-09-21

    A sensitive fluorescence turn-on biosensing platform for protein kinase activity assay has been developed based on fluorescence resonance energy transfer (FRET) between a fluorophore labeled peptide and a water soluble cationic conjugated polymer (CCP). The CCP-based assay is based on the electrostatic interaction between the peptide and the CCP. The FRET efficiency will change with the changing charges around the peptide after phosphorylation. The feasibility of this method has been demonstrated by sensitive measurement of the activity of cAMP-dependent protein kinase (PKA) with a low detection limit (0.3 mU μL(-1)). Based on its simple mechanism, this assay is also sensitive and robust enough to be applied to the evaluation of PKA inhibitor H-89. The IC50 value, the half maximal inhibitory concentration, was 40 nM. Furthermore, our method has excellent selectivity. CCP-based assay is sensitive, versatile, cost-effective and easy to operate, so, this method is a promising candidate for kinase activity assay and inhibitor screening.

  18. In Vivo PET Imaging of the Cancer Integrin αvβ6 Using (68)Ga-Labeled Cyclic RGD Nonapeptides.

    PubMed

    Notni, Johannes; Reich, Dominik; Maltsev, Oleg V; Kapp, Tobias G; Steiger, Katja; Hoffmann, Frauke; Esposito, Irene; Weichert, Wilko; Kessler, Horst; Wester, Hans-Jürgen

    2017-04-01

    Expression of the cellular transmembrane receptor αvβ6 integrin is essentially restricted to malignant epithelial cells in carcinomas of a broad variety of lineages, whereas it is virtually absent in normal adult tissues. Thus, it is a highly attractive target for tumor imaging and therapy. Furthermore, αvβ6 integrin plays an important role for the epithelial-mesenchymal interaction and the development of fibrosis. Methods: On the basis of the (68)Ga chelators TRAP (triazacyclononane-triphosphinate) and NODAGA, we synthesized mono-, di-, and trimeric conjugates of the αvβ6 integrin-selective peptide cyclo(FRGDLAFp(NMe)K) via click chemistry. These were labeled with (68)Ga and screened regarding their suitability for in vivo imaging of αvβ6 integrin expression by PET and ex vivo biodistribution in severe combined immunodeficiency mice bearing H2009 tumor (human lung adenocarcinoma) xenografts. For these, αvβ6 integrin expression in tumor and other tissues was determined by β6 immunohistochemistry. Results: Despite the multimers showing higher αvβ6 integrin affinities (23-120 pM) than the monomers (260 pM), the best results-that is, low background uptake and excellent tumor delineation-were obtained with the TRAP-based monomer (68)Ga-avebehexin. This compound showed the most favorable pharmacokinetics because of its high polarity (log D = -3.7) and presence of additional negative charges (carboxylates) on the chelator, promoting renal clearance. Although tumor uptake was low (0.65% ± 0.04% injected dose per gram tissue [%ID/g]), it was still higher than in all other organs except the kidneys, ranging from a maximum for the stomach (0.52 ± 0.04 %ID/g) to almost negligible for the pancreas (0.07 ± 0.01 %ID/g). A low but significant target expression in tumor, lung, and stomach was confirmed by immunohistochemistry. Conclusion: Because of highly sensitive PET imaging even of tissues with low αvβ6 integrin expression density, we anticipate clinical

  19. Cyclic multiverses

    NASA Astrophysics Data System (ADS)

    Marosek, Konrad; Dąbrowski, Mariusz P.; Balcerzak, Adam

    2016-09-01

    Using the idea of regularization of singularities due to the variability of the fundamental constants in cosmology we study the cyclic universe models. We find two models of oscillating and non-singular mass density and pressure (`non-singular' bounce) regularized by varying gravitational constant G despite the scale factor evolution is oscillating and having sharp turning points (`singular' bounce). Both violating (big-bang) and non-violating (phantom) null energy condition models appear. Then, we extend this idea on to the multiverse containing cyclic individual universes with either growing or decreasing entropy though leaving the net entropy constant. In order to get an insight into the key idea, we consider the doubleverse with the same geometrical evolution of the two `parallel' universes with their physical evolution [physical coupling constants c(t) and G(t)] being different. An interesting point is that there is a possibility to exchange the universes at the point of maximum expansion - the fact which was already noticed in quantum cosmology. Similar scenario is also possible within the framework of Brans-Dicke theory where varying G(t) is replaced by the dynamical Brans-Dicke field φ(t) though these theories are slightly different.

  20. Probing the conformation and 2D-distribution of pyrene-terminated redox-labeled poly(ethylene glycol) chains end-adsorbed on HOPG using cyclic voltammetry and atomic force electrochemical microscopy.

    PubMed

    Anne, Agnès; Bahri, Mohamed Ali; Chovin, Arnaud; Demaille, Christophe; Taofifenua, Cécilia

    2014-03-14

    The present paper aims at illustrating how end-attachment of water-soluble flexible chains bearing a terminal functional group onto graphene-like surfaces has to be carefully tuned to ensure the proper positioning of the functional moiety with respect to the anchoring surface. The model experimental system considered here consists of a layer of poly(ethylene glycol) (PEG) chains, bearing an adsorbing pyrene foot and a ferrocene (Fc) redox functional head, self-assembled onto highly oriented pyrolytic graphite (HOPG). Cyclic voltammetry is used to accurately measure the chain coverage and gain insights into the microenvironment experienced by the Fc heads. Molecule-touching atomic force electrochemical microscopy (Mt/AFM-SECM) is used to simultaneously probe the chain conformation and the position of the Fc heads within the layer, and also to map the 2D-distribution of the chains over the surface. This multiscale electrochemical approach allows us to show that whereas Fc-PEG-pyrene readily self-assembles to form extremely homogeneous layers, the strongly hydrophobic nature of graphite planes results in a complex coverage-dependent structure of the PEG layer due to the interaction of the ferrocene label with the HOPG surface. It is shown that, even though pyrene is known to adsorb particularly strongly onto HOPG, the more weakly adsorbing terminal ferrocene can also act as the chain anchoring moiety especially at low coverage. However we show that beyond a critical coverage value the Fc-PEG-pyrene chains adopt an ideal "foot-on" end-attached conformation allowing the Fc head to explore a volume away from the surface solely limited by the PEG chain elasticity.

  1. Multimodal imaging of integrin receptor-positive tumors by bioluminescence, fluorescence, gamma scintigraphy, and single-photon emission computed tomography using a cyclic RGD peptide labeled with a near-infrared fluorescent dye and a radionuclide.

    PubMed

    Edwards, W Barry; Akers, Walter J; Ye, Yunpeng; Cheney, Philip P; Bloch, Sharon; Xu, Baogang; Laforest, Richard; Achilefu, Samuel

    2009-01-01

    Integrins, particularly the alpha(v)beta(3) heterodimers, play important roles in tumor-induced angiogenesis and invasiveness. To image the expression pattern of the alpha(v)beta(3) integrin in tumors through a multimodality imaging paradigm, we prepared a cyclic RGDyK peptide analogue (LS308) bearing a tetraazamacrocycle 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA) and a lipophilic near-infrared (NIR) fluorescent dye cypate. The alpha(v)beta(3) integrin binding affinity and the internalization properties of LS308 mediated by the alpha(v)beta(3) integrin in 4t1luc cells were investigated by receptor binding assay and fluorescence microscopy, respectively. The in vivo distribution of (111)In-labeled LS308 in a 4t1luc tumor-bearing mouse model was studied by fluorescence, bioluminescence, planar gamma, and single-photon emission computed tomography (SPECT). The results show that LS308 has high affinity for alpha(v)beta(3) integrin and internalized preferentially via the alpha(v)beta(3) integrin-mediated endocytosis in 4t1luc cells. We also found that LS308 selectively accumulated in alpha(v)beta(3)-positve tumors in a receptor-specific manner and was visualized by the four imaging methods. Whereas the endogenous bioluminescence imaging identified the ensemble of the tumor tissue, the fluorescence and SPECT methods with the exogenous contrast agent LS308 reported the local expression of alpha(v)beta(3) integrin. Thus, the multimodal imaging approach could provide important complementary diagnostic information for monitoring the efficacy of new antiangiogenic drugs.

  2. The practicality of nanoceria-PAN-based (68)Ge/(68)Ga generator toward preparation of (68)Ga-labeled cyclic RGD dimer as a potential PET radiotracer for tumor imaging.

    PubMed

    Chakraborty, Sudipta; Chakravarty, Rubel; Sarma, Haladhar D; Dash, Ashutosh; Pillai, M R A

    2013-02-01

    Cyclic RGD (Arg-Gly-Asp) peptides radiolabeled with (68)Ga have great potential for the early tumor detection and noninvasive monitoring of tumor metastasis and therapeutic response. Herein, the preparation of (68)Ga-labeled DOTA-E[c(RGDfK)](2) (DOTA=1,4,7,10-tetraazacylododecane-1,4,7,10-tetracetic acid; E=Glutamic acid; R=Arginine; G=Glycine; D=Aspartic acid; f=phenyl alanine; K=lysine) using (68)Ga directly eluted from a nanoceria-polyacrylonitrile (CeO(2)-PAN)-based (68)Ge/(68)Ga generator developed in-house was reported. The (68)Ga complex of DOTA-E[c(RGDfK)](2) was synthesized with >98% radiochemical purity by incubating 20 μg of the conjugate with (68)GaCl(3) (74-111 MBq) in acetate buffer (pH 3.5-4.0) at 90°C for 10 minutes. The complex exhibited excellent in vitro stability in 0.1 M EDTA solution at room temperature upto 1 hour studied (radiochemical purity: 98.0%). The biological efficacy of the radiolabeled conjugate was studied in C57/BL6 mice bearing melanoma tumors. The results of the biodistribution studies revealed significant tumor uptake (4.14±0.54%ID/g) within 10 minutes postinjection (p.i.), which increased further to 4.61±0.31%ID/g at 30 minutes p.i. The tumor-to-blood ratio was found to increase from 1.75±0.42 at 10 minutes p.i. to 2.25±0.20 at 60 minutes p.i., whereas the tumor-to-liver and tumor-to-muscle ratio between the same time points increased from 2.71±0.76 to 3.31±0.84 and 5.37±1.08 to 8.97±1.32, respectively. The study successfully demonstrated the preparation of (68)Ga-DOTA-E[c(RGDfK)](2) as a potential positron-emission tomography radiotracer for possible use in tumor imaging by using (68)Ga eluted from a reliable, easy-to-handle (68)Ge/(68)Ga generator developed in-house, without any postelution purification of (68)Ga.

  3. Plant Cyclic Nucleotide Signalling

    PubMed Central

    Martinez-Atienza, Juliana; Van Ingelgem, Carl; Roef, Luc

    2007-01-01

    The presence of the cyclic nucleotides 3′,5′-cyclic adenyl monophosphate (cAMP) and 3′,5′-cyclic guanyl monophosphate (cGMP) in plants is now generally accepted. In addition, cAMP and cGMP have been implicated in the regulation of important plant processes such as stomatal functioning, monovalent and divalent cation fluxes, chloroplast development, gibberellic acid signalling, pathogen response and gene transcription. However, very little is known regarding the components of cyclic nucleotide signalling in plants. In this addendum, the evidence for specific mechanisms of plant cyclic nucleotide signalling is evaluated and discussed. PMID:19704553

  4. Food Labels

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Food Labels KidsHealth > For Teens > Food Labels Print A ... have at least 95% organic ingredients. continue Making Food Labels Work for You The first step in ...

  5. Affordable Cyclic Voltammetry

    ERIC Educational Resources Information Center

    Stewart, Greg; Kuntzleman, Thomas S.; Amend, John R.; Collins, Michael J.

    2009-01-01

    Cyclic voltammetry is an important component of the undergraduate chemical curriculum. Unfortunately, undergraduate students rarely have the opportunity to conduct experiments in cyclic voltammetry owing to the high cost of potentiostats, which are required to control these experiments. By using MicroLab data acquisition interfaces in conjunction…

  6. Affordable Cyclic Voltammetry

    ERIC Educational Resources Information Center

    Stewart, Greg; Kuntzleman, Thomas S.; Amend, John R.; Collins, Michael J.

    2009-01-01

    Cyclic voltammetry is an important component of the undergraduate chemical curriculum. Unfortunately, undergraduate students rarely have the opportunity to conduct experiments in cyclic voltammetry owing to the high cost of potentiostats, which are required to control these experiments. By using MicroLab data acquisition interfaces in conjunction…

  7. Designing cyclic universe models.

    PubMed

    Khoury, Justin; Steinhardt, Paul J; Turok, Neil

    2004-01-23

    The phenomenological constraints on the scalar field potential in cyclic models of the Universe are presented. We show that cyclic models require a comparable degree of tuning to that needed for inflationary models. The constraints are reduced to a set of simple design rules including "fast-roll" parameters analogous to the "slow-roll" parameters in inflation.

  8. Cyclic Hematopoiesis: animal models

    SciTech Connect

    Jones, J.B.; Lange, R.D.

    1983-08-01

    The four existing animal models of cyclic hematopoiesis are briefly described. The unusual erythropoietin (Ep) responses of the W/Wv mouse, the Sl/Sld mouse, and cyclic hematopoietic dog are reviewed. The facts reviewed indicate that the bone marrow itself is capable of influencing regulatory events of hematopoiesis.

  9. Novel pH-Sensitive Cyclic Peptides

    PubMed Central

    Weerakkody, Dhammika; Moshnikova, Anna; El-Sayed, Naglaa Salem; Adochite, Ramona-Cosmina; Slaybaugh, Gregory; Golijanin, Jovana; Tiwari, Rakesh K.; Andreev, Oleg A.; Parang, Keykavous; Reshetnyak, Yana K.

    2016-01-01

    A series of cyclic peptides containing a number of tryptophan (W) and glutamic acid (E) residues were synthesized and evaluated as pH-sensitive agents for targeting of acidic tissue and pH-dependent cytoplasmic delivery of molecules. Biophysical studies revealed the molecular mechanism of peptides action and localization within the lipid bilayer of the membrane at high and low pHs. The symmetric, c[(WE)4WC], and asymmetric, c[E4W5C], cyclic peptides translocated amanitin, a polar cargo molecule of similar size, across the lipid bilayer and induced cell death in a pH- and concentration-dependent manner. Fluorescently-labelled peptides were evaluated for targeting of acidic 4T1 mammary tumors in mice. The highest tumor to muscle ratio (5.6) was established for asymmetric cyclic peptide, c[E4W5C], at 24 hours after intravenous administration. pH-insensitive cyclic peptide c[R4W5C], where glutamic acid residues (E) were replaced by positively charged arginine residues (R), did not exhibit tumor targeting. We have introduced a novel class of cyclic peptides, which can be utilized as a new pH-sensitive tool in investigation or targeting of acidic tissue. PMID:27515582

  10. Cyclic control stick

    DOEpatents

    Whitaker, Charles N.; Zimmermann, Richard E.

    1989-01-01

    A cyclic control stick of the type used in helicopters for reducing the safety hazards associated with such a mechanism in the event of a crewman being thrown violently into contact with the cyclic control stick resulting from a crash or the like. The cyclic control stick is configured to break away upon the exertion of an impact force which exceeds a predetermined value and/or is exerted for more than a momentary time duration. The cyclic control stick is also configured to be adjustable so as to locate the grip thereof as far away from the crewman as possible for safety reasons without comprising the comfort of the crewman or the use of the control stick, and a crushable pad is provided on the top of the grip for impact energy absorbing purposes.

  11. Cyclic steps on ice

    NASA Astrophysics Data System (ADS)

    Yokokawa, M.; Izumi, N.; Naito, K.; Parker, G.; Yamada, T.; Greve, R.

    2016-05-01

    Boundary waves often form at the interface between ice and fluid flowing adjacent to it, such as ripples under river ice covers, and steps on the bed of supraglacial meltwater channels. They may also be formed by wind, such as the megadunes on the Antarctic ice sheet. Spiral troughs on the polar ice caps of Mars have been interpreted to be cyclic steps formed by katabatic wind blowing over ice. Cyclic steps are relatives of upstream-migrating antidunes. Cyclic step formation on ice is not only a mechanical but also a thermodynamic process. There have been very few studies on the formation of either cyclic steps or upstream-migrating antidunes on ice. In this study, we performed flume experiments to reproduce cyclic steps on ice by flowing water, and found that trains of steps form when the Froude number is larger than unity. The features of those steps allow them to be identified as ice-bed analogs of cyclic steps in alluvial and bedrock rivers. We performed a linear stability analysis and obtained a physical explanation of the formation of upstream-migrating antidunes, i.e., precursors of cyclic steps. We compared the results of experiments with the predictions of the analysis and found the observed steps fall in the range where the analysis predicts interfacial instability. We also found that short antidune-like undulations formed as a precursor to the appearance of well-defined steps. This fact suggests that such antidune-like undulations correspond to the instability predicted by the analysis and are precursors of cyclic steps.

  12. Cyclic polymers from alkynes.

    PubMed

    Roland, Christopher D; Li, Hong; Abboud, Khalil A; Wagener, Kenneth B; Veige, Adam S

    2016-08-01

    Cyclic polymers have dramatically different physical properties compared with those of their equivalent linear counterparts. However, the exploration of cyclic polymers is limited because of the inherent challenges associated with their synthesis. Conjugated linear polyacetylenes are important materials for electrical conductivity, paramagnetic susceptibility, optical nonlinearity, photoconductivity, gas permeability, liquid crystallinity and chain helicity. However, their cyclic analogues are unknown, and therefore the ability to examine how a cyclic topology influences their properties is currently not possible. We have solved this challenge and now report a tungsten catalyst supported by a tetraanionic pincer ligand that can rapidly polymerize alkynes to form conjugated macrocycles in high yield. The catalyst works by tethering the ends of the polymer to the metal centre to overcome the inherent entropic penalty of cyclization. Gel-permeation chromatography, dynamic and static light scattering, viscometry and chemical tests are all consistent with theoretical predictions and provide unambiguous confirmation of a cyclic topology. Access to a wide variety of new cyclic polymers is now possible by simply choosing the appropriate alkyne monomer.

  13. Cyclic polymers from alkynes

    NASA Astrophysics Data System (ADS)

    Roland, Christopher D.; Li, Hong; Abboud, Khalil A.; Wagener, Kenneth B.; Veige, Adam S.

    2016-08-01

    Cyclic polymers have dramatically different physical properties compared with those of their equivalent linear counterparts. However, the exploration of cyclic polymers is limited because of the inherent challenges associated with their synthesis. Conjugated linear polyacetylenes are important materials for electrical conductivity, paramagnetic susceptibility, optical nonlinearity, photoconductivity, gas permeability, liquid crystallinity and chain helicity. However, their cyclic analogues are unknown, and therefore the ability to examine how a cyclic topology influences their properties is currently not possible. We have solved this challenge and now report a tungsten catalyst supported by a tetraanionic pincer ligand that can rapidly polymerize alkynes to form conjugated macrocycles in high yield. The catalyst works by tethering the ends of the polymer to the metal centre to overcome the inherent entropic penalty of cyclization. Gel-permeation chromatography, dynamic and static light scattering, viscometry and chemical tests are all consistent with theoretical predictions and provide unambiguous confirmation of a cyclic topology. Access to a wide variety of new cyclic polymers is now possible by simply choosing the appropriate alkyne monomer.

  14. A homogeneous immunoassay for cyclic nucleotides based on chemiluminescence energy transfer.

    PubMed Central

    Campbell, A K; Patel, A

    1983-01-01

    A chemiluminescent derivative of cyclic AMP, aminobutylethylisoluminol succinyl cyclic AMP (ABEI-scAMP), was synthesized in order to develop a homogeneous immunoassay based on non-radiative energy transfer. ABEI-scAMP was chemiluminescent (5.1 X 10(18) luminescent counts X mol-1 at pH 13), pure (greater than 95%) stable and immunologically active. A conventional immunoassay was established using ABEI-scAMP and a solid-phase anti-(cyclic AMP) immunoglobulin G which could detect cyclic AMP at least down to 25fmol. A homogeneous immunoassay for cyclic AMP was established by measuring the shift in wavelength from 460 to 525nm which occurred when ABEI-scAMP was bound to fluorescein-labelled anti-(cyclic AMP) immunoglobulin G. The assay was at least as sensitive as the conventional radioimmunoassay using cyclic [3H]AMP and could measure cyclic AMP over the range 1-1000nM. The homogeneous chemiluminescent energy transfer assay was also able to quantify the association and dissociation of antibody-antigen complexes. Chemiluminescence energy transfer occurred between fluorescein-labelled antibodies and several other ABEI-labelled antigens (Mr values 314-150000) including progesterone, cyclic GMP, complement component C9 and immunoglobulin G. The results provide a homogeneous immunoassay capable of measuring free cyclic AMP under conditions likely to exist inside cells. PMID:6316935

  15. Electrochemical Quartz Crystal Microbalance Monitoring of the Cyclic Voltammetric Deposition of Polyaniline

    ERIC Educational Resources Information Center

    Xie, Qingji; Li, Zhili; Deng, Chunyan; Liu, Meiling; Zhang, Youyu; Ma, Ming; Xia, Shaoxi; Xiao, Xiaoming; Yin, Dulin; Yao, Shouzhuo

    2007-01-01

    A real-time, labeled-free and nanogram-sensitive mass sensor, electrochemical quartz crystal microbalance (EQCM) is used to monitor a cyclic voltammetric deposition of polyaniline (PANI). The results determined that the efficiency for PANI deposition and the anion-doping ratio is calculated in one single cyclic voltammetric.

  16. Electrochemical Quartz Crystal Microbalance Monitoring of the Cyclic Voltammetric Deposition of Polyaniline

    ERIC Educational Resources Information Center

    Xie, Qingji; Li, Zhili; Deng, Chunyan; Liu, Meiling; Zhang, Youyu; Ma, Ming; Xia, Shaoxi; Xiao, Xiaoming; Yin, Dulin; Yao, Shouzhuo

    2007-01-01

    A real-time, labeled-free and nanogram-sensitive mass sensor, electrochemical quartz crystal microbalance (EQCM) is used to monitor a cyclic voltammetric deposition of polyaniline (PANI). The results determined that the efficiency for PANI deposition and the anion-doping ratio is calculated in one single cyclic voltammetric.

  17. The cyclic reduction algorithm

    NASA Astrophysics Data System (ADS)

    Bini, Dario; Meini, Beatrice

    2009-05-01

    Cyclic reduction is an algorithm invented by G.H. Golub and R. W. Hockney in the mid 1960s for solving linear systems related to the finite differences discretization of the Poisson equation over a rectangle. Among the algorithms of Gene Golub, it is one of the most versatile and powerful ever created. Recently, it has been applied to solve different problems from different applicative areas. In this paper we survey the main features of cyclic reduction, relate it to properties of analytic functions, recall its extension to solving more general finite and infinite linear systems, and different kinds of nonlinear matrix equations, including algebraic Riccati equations, with applications to Markov chains, queueing models and transport theory. Some new results concerning the convergence properties of cyclic reduction and its applicability are proved under very weak assumptions. New formulae for overcoming breakdown are provided.

  18. Nutrition Labeling

    NASA Astrophysics Data System (ADS)

    Metzger, Lloyd E.

    Nutrition labeling regulations differ in countries around the world. The focus of this chapter is on nutrition labeling regulations in the USA, as specified by the Food and Drug Administration (FDA) and the Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA). A major reason for analyzing the chemical components of foods in the USA is nutrition labeling regulations. Nutrition label information is not only legally required in many countries, but also is of increasing importance to consumers as they focus more on health and wellness.

  19. Cyclic membrane separation process

    DOEpatents

    Bowser, John

    2004-04-13

    A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In one of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the other part, the membrane is inoperative while gas pressure rises in the ullage. Ambient air is charged to the membrane separation unit during the latter part of the cycle.

  20. Cyclic membrane separation process

    DOEpatents

    Nemser, Stuart M.

    2005-05-03

    A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In the first part of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the second part, the membrane is inoperative while gas pressure rises in the ullage. In one aspect of this invention, a vacuum is drawn in the membrane separation unit thus reducing overall VOC emissions.

  1. Cyclic Opioid Peptides.

    PubMed

    Remesic, Michael; Lee, Yeon Sun; Hruby, Victor J

    2016-01-01

    For decades the opioid receptors have been an attractive therapeutic target for the treatment of pain. Since the first discovery of enkephalin, approximately a dozen endogenous opioid peptides have been known to produce opioid activity and analgesia, but their therapeutics have been limited mainly due to low blood brain barrier penetration and poor resistance to proteolytic degradation. One versatile approach to overcome these drawbacks is the cyclization of linear peptides to cyclic peptides with constrained topographical structure. Compared to their linear parents, cyclic analogs exhibit better metabolic stability, lower offtarget toxicity, and improved bioavailability. Extensive structure-activity relationship studies have uncovered promising compounds for the treatment of pain as well as further elucidate structural elements required for selective opioid receptor activity. The benefits that come with employing cyclization can be further enhanced through the generation of polycyclic derivatives. Opioid ligands generally have a short peptide chain and thus the realm of polycyclic peptides has yet to be explored. In this review, a brief history of designing ligands for the opioid receptors, including classic linear and cyclic ligands, is discussed along with recent approaches and successes of cyclic peptide ligands for the receptors. Various scaffolds and approaches to improve bioavailability are elaborated and concluded with a discourse towards polycyclic peptides.

  2. Cyclic Voltammetry Experiment.

    ERIC Educational Resources Information Center

    Van Benschoten, James J.; And Others

    1983-01-01

    Describes a three-part experiment designed to introduce cyclic voltammetry to graduate/undergraduate students. Part 1 demonstrates formal reduction potential, redox electron transfer, diffusion coefficient, and electrochemical reversibility. Part 2 investigates electrochemical behavior of acetaminophen. Part 3 examines such experimental variables…

  3. Cyclic Voltammetry Experiment.

    ERIC Educational Resources Information Center

    Van Benschoten, James J.; And Others

    1983-01-01

    Describes a three-part experiment designed to introduce cyclic voltammetry to graduate/undergraduate students. Part 1 demonstrates formal reduction potential, redox electron transfer, diffusion coefficient, and electrochemical reversibility. Part 2 investigates electrochemical behavior of acetaminophen. Part 3 examines such experimental variables…

  4. Cyclic networks of quantum gates

    NASA Astrophysics Data System (ADS)

    Cabauy, Peter

    In this thesis we first give an introduction to the basic aspects of quantum computation followed by an analysis of networks of quantum logic gates where the qubit lines are loops (cyclic). Thus far, investigations into cyclic networks of quantum logic gates have not been examined (as far as we know) by the quantum information community. In our investigations of cyclic quantum networks we have studied simple, one and two qubit systems. The analysis includes: classifying networks into groups, the dynamics of the qubits in a cyclic quantum network, and the perturbation effects of an external qubit acting on a cyclic quantum network. The analysis will be followed by a discussion on quantum algorithms and quantum information processing with cyclic quantum networks, a novel implementation of a cyclic network quantum memory and a discussion of quantum sensors via cyclic quantum networks.

  5. Cyclic quantum teleportation

    NASA Astrophysics Data System (ADS)

    Chen, Ying-Xuan; Du, Jing; Liu, Si-Yuan; Wang, Xiao-Hui

    2017-08-01

    We propose a scheme of cyclic quantum teleportation for three unknown qubits using six-qubit maximally entangled state as the quantum channel. Suppose there are three observers Alice, Bob and Charlie, each of them has been given a quantum system such as a photon or spin-1/2 particle, prepared in state unknown to them. We show how to implement the cyclic quantum teleportation where Alice can transfer her single-qubit state of qubit a to Bob, Bob can transfer his single-qubit state of qubit b to Charlie and Charlie can also transfer his single-qubit state of qubit c to Alice. We can also implement the cyclic quantum teleportation with N≥slant 3 observers by constructing a 2 N-qubit maximally entangled state as the quantum channel. By changing the quantum channel, we can change the direction of teleportation. Therefore, our scheme can realize teleportation in quantum information networks with N observers in different directions, and the security of our scheme is also investigated at the end of the paper.

  6. Metallo-supramolecular cyclic polymers.

    PubMed

    Zhang, Ke; Zha, Yongping; Peng, Bo; Chen, Yongming; Tew, Gregory N

    2013-10-30

    Cyclic brush polymers represent an exciting new macromolecular topology. For the first time, this new topology has been combined with metallo-supramolecular interactions to construct novel cyclic brush polymers. Here, ring-expansion metathesis polymerization was used to synthesize a universal cyclic template with a polynorbornene backbone, which was further modified with the metal-chelating synthon terpyridine. The terpyridine side chains served as the key supramolecular unit for the creation of cyclic polymer brushes and gels. This metallo-supramolecular functionality allowed direct visualization of the cyclic brush polymers by transmission electron microscopy for the first time. This demonstration should open a new area in which supramolecular interactions are used to build an array of novel cyclic brush copolymers as well as other cyclic-polymer-based architectures generating new materials.

  7. Cyclic torsion testing

    NASA Technical Reports Server (NTRS)

    Leese, G. E.

    1984-01-01

    Torsional fatigue testing and data analysis procedures are described. Since there are no standards governing cyclic torsion testing that are generally accepted on a widespread basis by the technical community, the different approaches that dominate current experimental activity, and the ramifications of each are discussed. Particular attention is given to the theoretical and experimental difficulties that have paced refinement and general acceptance of test procedures. Finally, specific quantities and nomenclature modelled after analagous axial fatigue properties are suggested as an effective way to communicate torsional fatigue results until accepted standards are established.

  8. An Early Cyclic Universe

    NASA Astrophysics Data System (ADS)

    Duhe, William; Biswas, Tirthibir

    2014-03-01

    We provide a comprehensive numerical study of the Emergent Cyclic Inflation scenario. This is a scenario where instead of traditional monotonic slow roll inflation, the universe expands over numerous short asymmetric cycles due to the production of entropy via interactions among different species. This is one of the very few scenarios of inflation which provides a nonsingular geodesically complete space-time and does not require any ``reheating'' mechanism. A special thanks to Loyola University for an excellent community to help this project grow.

  9. [Asthma and cyclic neutropenia].

    PubMed

    Salazar Cabrera, A N; Berrón Pérez, R; Ortega Martell, J A; Onuma Takane, E

    1996-01-01

    We report a male with history of recurrent infections (recurrent oral aphtous disease [ROAD], middle ear infections and pharyngo amigdalitis) every 3 weeks since he was 7 months old. At the age of 3 years cyclic neutropenia was diagnosed with cyclic fall in the total neutrophil count in blood smear every 21 days and prophylactic antimicrobial therapy was indicated. Episodic events every 3 weeks of acute asthma and allergic rhinitis were detected at the age of 6 years old and specific immunotherapy to Bermuda grass was given during 3 years with markedly improvement in his allergic condition but not in the ROAD. He came back until the age of 16 with episodic acute asthma and ROAD. The total neutrophil count failed to 0 every 21 days and surprisingly the total eosinophil count increased up to 2,000 at the same time, with elevation of serum IgE (412 Ul/mL). Specific immunotherapy to D.pt. and Aller.a. and therapy with timomodulin was indicated. After 3 months we observed clinical improvement in the asthmatic condition and the ROAD disappeared, but the total neutrophil count did not improve. We present this case as a rare association between 2 diseases with probably no etiological relationship but may be physiopatological that could help to understand more the pathogenesis of asthma.

  10. Ekpyrotic and cyclic cosmology

    NASA Astrophysics Data System (ADS)

    Lehners, Jean-Luc

    2008-09-01

    Ekpyrotic and cyclic cosmologies provide theories of the very early and of the very late universe. In these models, the big bang is described as a collision of branes — and thus the big bang is not the beginning of time. Before the big bang, there is an ekpyrotic phase with equation of state w=Pρ≫1 (where P is the average pressure and ρ the average energy density) during which the universe slowly contracts. This phase resolves the standard cosmological puzzles and generates a nearly scale-invariant spectrum of cosmological perturbations containing a significant non-Gaussian component. At the same time it produces small-amplitude gravitational waves with a blue spectrum. The dark energy dominating the present-day cosmological evolution is reinterpreted as a small attractive force between our brane and a parallel one. This force eventually induces a new ekpyrotic phase and a new brane collision, leading to the idea of a cyclic universe. This review discusses the detailed properties of these models, their embedding in M-theory and their viability, with an emphasis on open issues and observational signatures.

  11. Cyclic generalized projection MRI.

    PubMed

    Sarty, Gordon E

    2015-04-01

    Progress in the development of portable MRI hinges on the ability to use lightweight magnets that have non-uniform magnetic fields. An image encoding method and mathematical procedure for recovering the image from the NMR signal from non-uniform magnets with closed isomagnetic contours is given. Individual frequencies in an NMR signal from an object in a non-uniform magnetic field give rise to integrals of the object along contours of constant magnetic field: generalized projections. With closed isomagnetic field contours a simple, cyclic, direct reconstruction of the image from the generalized projections is possible when the magnet and RF transmit coil are held fixed relative to the imaged object while the RF receive coil moves. Numerical simulations, using the Shepp and Logan mathematical phantom, were completed to show that the mathematical method works and to illustrate numerical limitations. The method is numerically verified and exact reconstruction demonstrated for discrete mathematical image phantoms. Correct knowledge of the RF receive field is necessary or severe image distortions will result. The cyclic mathematical reconstruction method presented here will be useful for portable MRI schemes that use non-uniform magnets with closed isomagnetic contours along with mechanically or electronically moving the RF receive coils.

  12. Food labeling

    MedlinePlus

    ... States Food and Drug Administration (FDA) has proposed making changes to the food labels that may correct these problems. AMOUNTS PER SERVING The total calories and the calories from fat are listed. These numbers help consumers make decisions about fat intake. The list of nutrients includes ...

  13. Ethanol-induced loss of brain cyclic AMP binding proteins: correlation with growth suppression

    SciTech Connect

    Pennington, S.; Kalmus, G.

    1987-05-01

    Brain hypoplasia secondary to maternal ethanol consumption is a common fetal defect observed in all models of fetal alcohol syndrome. The molecular mechanism by which ethanol inhibits growth is unknown but has been hypothesized to involve ethanol-induced changes in the activity of cyclic-AMP stimulated protein kinase. Acute and chronic alcohol exposure elevate cyclic AMP level in many tissues, including brain. This increase in cyclic AMP should increase the phosphorylating activity of kinase by increasing the amount of dissociated (active) kinase catalytic subunit. In 7-day embryonic chick brains, ethanol-induced growth suppression was correlated with increased brain cyclic AMP content but neither basal nor cyclic AMP stimulated kinase catalytic activity was increased. However, the levels of cyclic AMP binding protein (kinase regulatory subunit) were significantly lowered by ethanol exposure. Measured as either /sup 3/H cyclic AMP binding or as 8-azido cyclic AM/sup 32/P labeling, ethanol-exposed brains had significantly less cyclic AMP binding activity (51 +/- 14 versus 29 +/- 10 units/..mu..g protein for 8-azido cyclic AMP binding). These findings suggest that ethanol's effect on kinase activity may involve more than ethanol-induced activation of adenylate cyclase.

  14. Cyclic GMP transporters.

    PubMed

    Sager, Georg

    2004-11-01

    The biokinetics of guanosine 3',5'-cyclic monophosphate (cGMP) is characterized by three distinct processes: synthesis by guanylate cyclases (GCs), conversion of cGMP to GMP by cyclic nucleotide phosphodiesterases (PDEs) and the excretion of unchanged cGMP by transport proteins in the cell membrane. Efflux is observed in virtually all cell types including cells which originate from brain. Studies of intact cells, in which metabolic inhibitors and probenecid reduced extrusion of cGMP and wherein cGMP was extruded against concentration gradients, indicated the existence of ATP requiring organic anion transport system(s). Functional studies of inside-out vesicles have revealed cGMP transport systems wherein translocation is coupled to hydrolysis of ATP. The extrusion of cGMP is inhibited by a number of unrelated compounds and this indicates that cGMP is substrate for multispecific transporters. Recent transfection studies suggest that members of the MRP (multidrug resistance protein) family; MRP4, MRP5 and MRP8 translocate cGMP across the cell membrane. Many of the MRPs have been detected in brain. In addition tertiary active transport by the organic anion transporter family has also been identified. At least one member (OAT1) shows relative high affinity for cGMP and is also expressed in brain. The biological significance of cGMP transporters has to be clarified. Their role in cGMP biokinetics, being responsible for one of the cellular elimination pathways, is well established. However, there is growing evidence that extracellular cGMP has effects on cell physiology and pathophysiology by an auto- or paracrine mechanism.

  15. Synthesis of cyclic Py-Im polyamide libraries.

    PubMed

    Li, Benjamin C; Montgomery, David C; Puckett, James W; Dervan, Peter B

    2013-01-04

    Cyclic Py-Im polyamides containing two GABA turn units exhibit enhanced DNA binding affinity, but extensive studies of their biological properties have been hindered due to synthetic inaccessibility. A facile modular approach toward cyclic polyamides has been developed via microwave-assisted solid-phase synthesis of hairpin amino acid oligomer intermediates followed by macrocyclization. A focused library of cyclic polyamides 1-7 targeted to the androgen response element (ARE) and the estrogen response element (ERE) were synthesized in 12-17% overall yield. The Fmoc protection strategy also allows for selective modifications on the GABA turn units that have been shown to improve cellular uptake properties. The DNA binding affinities of a library of cyclic polyamides were measured by DNA thermal denaturation assays and compared to the corresponding hairpin polyamides. Fluorescein-labeled cyclic polyamides have been synthesized and imaged via confocal microscopy in A549 and T47D cell lines. The IC(50) values of compounds 1-7 and 9-11 were determined, revealing remarkably varying levels of cytotoxicity.

  16. Radioiodination of Aryl-Alkyl Cyclic Sulfates

    PubMed Central

    Mushti, Chandra; Papisov, Mikhail I.

    2015-01-01

    Among the currently available positron emitters suitable for Positron Emission Tomography (PET), 124I has the longest physical half-life (4.2 days). The long half-life and well-investigated behavior of iodine in vivo makes 124I very attractive for pharmacological studies. In this communication, we describe a simple yet effective method for the synthesis of novel 124I labeled compounds intended for PET imaging of arylsulfatase activity in vivo. Arylsulfatases have important biological functions, and genetic deficiencies of such functions require pharmacological replacement, the efficacy of which must be properly and non-invasively evaluated. These enzymes, even though their natural substrates are mostly of aliphatic nature, hydrolyze phenolic sulfates to phenol and sulfuric acid. The availability of [124I]iodinated substrates is expected to provide a PET-based method for measuring their activity in vivo. The currently available methods of synthesis of iodinated arylsulfates usually require either introducing of a protected sulfate ester early in the synthesis or introduction of sulfate group at the end of synthesis in a separate step. The described method gives the desired product in one step from an aryl-alkyl cyclic sulfate. When treated with iodide, the source cyclic sulfate opens with substitution of iodide at the alkyl center and gives the desired arylsulfate monoester. PMID:23135631

  17. Introduction to Pesticide Labels

    EPA Pesticide Factsheets

    Pesticide product labels provide critical information about how to safely and legally handle and use pesticide products. Unlike most other types of product labels, pesticide labels are legally enforceable. Learn about pesticide product labels.

  18. Cyclic AMP in prokaryotes.

    PubMed Central

    Botsford, J L; Harman, J G

    1992-01-01

    Cyclic AMP (cAMP) is found in a variety of prokaryotes including both eubacteria and archaebacteria. cAMP plays a role in regulating gene expression, not only for the classic inducible catabolic operons, but also for other categories. In the enteric coliforms, the effects of cAMP on gene expression are mediated through its interaction with and allosteric modification of a cAMP-binding protein (CRP). The CRP-cAMP complex subsequently binds specific DNA sequences and either activates or inhibits transcription depending upon the positioning of the complex relative to the promoter. Enteric coliforms have provided a model to explore the mechanisms involved in controlling adenylate cyclase activity, in regulating adenylate cyclase synthesis, and in performing detailed examinations of CRP-cAMP complex-regulated gene expression. This review summarizes recent work focused on elucidating the molecular mechanisms of CRP-cAMP complex-mediated processes. For other bacteria, less detail is known. cAMP has been implicated in regulating antibiotic production, phototrophic growth, and pathogenesis. A role for cAMP has been suggested in nitrogen fixation. Often the only data that support cAMP involvement in these processes includes cAMP measurement, detection of the enzymes involved in cAMP metabolism, or observed effects of high concentrations of the nucleotide on cell growth. PMID:1315922

  19. Genetics Home Reference: cyclic neutropenia

    MedlinePlus

    ... infection, neutrophils release neutrophil elastase. This protein then modifies the function of certain cells and proteins to help fight the infection. ELANE gene mutations that cause cyclic neutropenia lead to an ...

  20. Cyclic Cushing's syndrome: an overview.

    PubMed

    Mantero, Franco; Scaroni, Carla M; Albiger, Nora M E

    2004-01-01

    Cyclic Cushing's syndrome (CS) involves rhythmic fluctuations in ACTH secretion resulting in a cyclic variation of adrenal steroid production. In the majority of cases, cyclic CS is caused by an ACTH-secreting pituitary adenoma, but it can also be due to ectopic ACTH production or an adrenal adenoma. This condition should be strongly suspected in patients with symptoms or signs of hypercortisolism but normal cortisol levels and paradoxical responses to the dexamethasone test, that may reflect an increasing or decreasing endogenous hormone activity. Dynamic tests are best interpreted if they are performed during a sustained period of hypercortisolism. Sometimes, it is necessary to confirm the diagnosis over lengthy periods of observation. Responses to treatment must be closely monitored, interpreted and evaluated with caution because of the potential variations in steroidogenesis. An original case report of a cyclic Cushing's syndrome is presented in this review.

  1. Cyclic mixmaster universes

    NASA Astrophysics Data System (ADS)

    Barrow, John D.; Ganguly, Chandrima

    2017-04-01

    We investigate the behavior of bouncing Bianchi type IX "mixmaster" universes in general relativity. This generalizes all previous studies of the cyclic behavior of closed spatially homogeneous universes with and without an entropy increase. We determine the behavior of models containing radiation by analytic and numerical integration and show that an increase of radiation entropy leads to an increasing cycle size and duration. We introduce a null energy condition violating ghost field to create a smooth, nonsingular bounce of finite size at the end of each cycle and compute the evolution through many cycles with and without an entropy increase injected at the start of each cycle. In the presence of increasing entropy, we find that the cycles grow larger and longer and the dynamics approach flatness, as in the isotropic case. However, successive cycles become increasingly anisotropic at the expansion maxima which is dominated by the general-relativistic effects of anisotropic 3-curvature. When the dynamics are significantly anisotropic, the 3-curvature is negative. However, it becomes positive after continued expansion drives the dynamics close enough to isotropy for the curvature to become positive and for gravitational collapse to ensue. In the presence of a positive cosmological constant, radiation, and a ghost field, we show that, for a very wide range of cosmological constant values, the growing oscillations always cease and the dynamics subsequently approach those of the isotropic de Sitter universe at late times. This model is not included in the scope of earlier cosmic no-hair theorems because the 3-curvature can be positive. In the case of a negative cosmological constant, radiation, and an ultrastiff field (to create nonsingular bounces), we show that a sequence of chaotic oscillations also occurs, with sensitive dependence on initial conditions. In all cases, we follow the oscillatory evolution of the scale factors, the shear, and the 3-curvature from

  2. Computer Simulation Of Cyclic Oxidation

    NASA Technical Reports Server (NTRS)

    Probst, H. B.; Lowell, C. E.

    1990-01-01

    Computer model developed to simulate cyclic oxidation of metals. With relatively few input parameters, kinetics of cyclic oxidation simulated for wide variety of temperatures, durations of cycles, and total numbers of cycles. Program written in BASICA and run on any IBM-compatible microcomputer. Used in variety of ways to aid experimental research. In minutes, effects of duration of cycle and/or number of cycles on oxidation kinetics of material surveyed.

  3. Cyclic Cushing's syndrome: an overview.

    PubMed

    Albiger, Nora Maria Elvira; Scaroni, Carla M; Mantero, Franco

    2007-11-01

    Cyclic Cushing's syndrome (CS) is a disorder in which glucocorticoid levels are alternately normal and high, the latter occurring in episodes that can last from a few days to several months. It is more common in children than in adults. Cyclic CS may be either of the two different forms of CS (ACTH-dependent or -independent CS). Clinically, it may present with one or many symptoms, depending on the duration of disease activity and the timing of the fluctuations. A serotoninergic influence, cyclic changes in central dopaminergic tone, spontaneous episodic hemorrhage in the tumor, and the action of inflammatory cytokines with antitumor properties are some of the mechanisms suggested to explain the physiopathology of this phenomenon but the exact mechanism remains to be clarified. The cyclic pattern of hypercortisolism can delay the final diagnosis of CS and make it difficult to interpret the results of dynamic tests. Patients may have paradoxical responses to dexamethasone that can reflect increasing or decreasing levels of endogenous activity. Hormone assessments have to be repeated periodically when a diagnosis of CS is suspected. The cyclic pattern can also interfere with medical treatment because patients may show unexpected clinical and biochemical signs of hypocortisolism when cortisol secretion cyclically returns to normal, so an accurate follow-up is mandatory in these patients.

  4. Cyclic antibiotic therapy for diverticular disease: a critical reappraisal.

    PubMed

    Zullo, Angelo; Hassan, Cesare; Maconi, Giovanni; Manes, Gianpiero; Tammaro, Gianfranco; De Francesco, Vincenzo; Annibale, Bruno; Ficano, Leonardo; Buri, Luigi; Gatto, Giovanni; Lorenzetti, Roberto; Campo, Salvatore M; Ierardi, Enzo; Pace, Fabio; Morini, Sergio

    2010-09-01

    Different symptoms have been attributed to uncomplicated diverticular disease (DD). Poor absorbable antibiotics are largely used for uncomplicated DD, mainly for symptom treatment and prevention of diverticulitis onset. Controlled trials on cyclic administration of rifaximin in DD patients were evaluated. Four controlled, including 1 double-blind and 3 open-label, randomized studies were available. Following a long-term cyclic therapy, a significant difference emerged in the global symptoms score (range: 0-18) between rifaximin plus fibers (from 6-6.5 to 1-2) and fibers alone (from 6.7 to 2-3.8), although the actual clinically relevance of such a very small difference remains to be ascertained. Moreover, a similar global symptom score reduction (from 6 to 2.4) can be achieved by simply recommending an inexpensive high-fiber diet. Current data suggest that cyclic rifaximin plus fibers significantly reduce the incidence of the first episode of acute diverticulitis as compared to fibers alone (1.03% vs 2.75%), but a cost-efficacy analysis is needed before this treatment can be routinely recommended. The available studies have been hampered by some limitations, and definite conclusions could not be drawn. The cost of a long-life, cyclic rifaximin therapy administered to all symptomatic DD patients would appear prohibitive.

  5. Gels based on cyclic polymers.

    PubMed

    Zhang, Ke; Lackey, Melissa A; Cui, Jun; Tew, Gregory N

    2011-03-23

    Cyclic poly(5-hydroxy-1-cyclooctene) (PACOE) was synthesized by ring-expansion metathesis polymerization (REMP), and thiol-ene chemistry was used to cross-link the internal double bonds in the PACOE backbone. This created a novel network material (gels formed from cyclic polymers) with unique structural units, where the cyclic PACOE main chains, which serve as secondary topological cross-linkages, were connected by primary intermolecular chemical cross-linkages. The resulting properties were notably different from those of traditional chemically cross-linked linear PACOE gels, whose gel fraction (GF) and modulus (G) increased while the swelling ratio (Q) decreased with increasing initial polymer concentration in the gel precursor solution (C(0)). For the gels formed from cyclic polymers, however, the GF, Q, and G all simultaneously increased as C(0) increased at the higher range. Furthermore, at the same preparation state (same C(0)), the swelling ability and the maximum strain at break of the gels formed from cyclic polymers were always greater than those of the gels formed from linear polymers, and these differences became more pronounced as C(0) increased.

  6. Pesticide Label Review Training

    EPA Pesticide Factsheets

    This training will help ensure that reviewers evaluate labels according to four core principles. It also will help pesticide registrants developing labels understand what EPA expects of pesticide labels, and what the Agency generally finds acceptable.

  7. Enzymatic Ugi Reaction with Amines and Cyclic Imines.

    PubMed

    Żądło-Dobrowolska, Anna; Kłossowski, Szymon; Koszelewski, Dominik; Paprocki, Daniel; Ostaszewski, Ryszard

    2016-11-07

    The application of the Ugi reaction to the construction of new peptide scaffolds is an important goal of organic chemistry. To date, there are no examples of the Ugi reaction being performed with a cyclic imine and amine simultaneously. The application of 2-substituted cyclic imines in an enzymatic three-component Ugi-type reaction provides an elegant and attractive synthesis of substituted pyrrolidine and piperidine derivatives in up to 60 % yield. Results on studies of the selection of an enzyme, amount of water, and solvent used in a novel three-component Ugi reaction and the limitations thereof are reported herein. The presented methodology exploiting enzyme promiscuity in the multicomponent reaction fulfills the requirements associated with green chemistry. Several methods, such as isotope labeling and enzyme inhibition, were used to probe the possible mechanism of this complex synthesis. This research is the first example of an enzyme-catalyzed Ugi-type reaction with an imine, amine, and isocyanide.

  8. Deep Label Distribution Learning With Label Ambiguity

    NASA Astrophysics Data System (ADS)

    Gao, Bin-Bin; Xing, Chao; Xie, Chen-Wei; Wu, Jianxin; Geng, Xin

    2017-06-01

    Convolutional Neural Networks (ConvNets) have achieved excellent recognition performance in various visual recognition tasks. A large labeled training set is one of the most important factors for its success. However, it is difficult to collect sufficient training images with precise labels in some domains such as apparent age estimation, head pose estimation, multi-label classification and semantic segmentation. Fortunately, there is ambiguous information among labels, which makes these tasks different from traditional classification. Based on this observation, we convert the label of each image into a discrete label distribution, and learn the label distribution by minimizing a Kullback-Leibler divergence between the predicted and ground-truth label distributions using deep ConvNets. The proposed DLDL (Deep Label Distribution Learning) method effectively utilizes the label ambiguity in both feature learning and classifier learning, which help prevent the network from over-fitting even when the training set is small. Experimental results show that the proposed approach produces significantly better results than state-of-the-art methods for age estimation and head pose estimation. At the same time, it also improves recognition performance for multi-label classification and semantic segmentation tasks.

  9. Color visualization of cyclic magnitudes

    NASA Astrophysics Data System (ADS)

    Restrepo, Alfredo; Estupiñán, Viviana

    2014-02-01

    We exploit the perceptual, circular ordering of the hues in a technique for the visualization of cyclic variables. The hue is thus meaningfully used for the indication of variables such as the azimuth and the units of the measurement of time. The cyclic (or circular) variables may be both of the continuous type or the discrete type; among the first there is azimuth and among the last you find the musical notes and the days of the week. A correspondence between the values of a cyclic variable and the chromatic hues, where the natural circular ordering of the variable is respected, is called a color code for the variable. We base such a choice of hues on an assignment of of the unique hues red, yellow, green and blue, or one of the 8 even permutations of this ordered list, to 4 cardinal values of the cyclic variable, suitably ordered; color codes based on only 3 cardinal points are also possible. Color codes, being intuitive, are easy to remember. A possible low accuracy when reading instruments that use this technique is compensated by fast, ludic and intuitive readings; also, the use of a referential frame makes readings precise. An achromatic version of the technique, that can be used by dichromatic people, is proposed.

  10. Buffering in cyclic gene networks

    NASA Astrophysics Data System (ADS)

    Glyzin, S. D.; Kolesov, A. Yu.; Rozov, N. Kh.

    2016-06-01

    We consider cyclic chains of unidirectionally coupled delay differential-difference equations that are mathematical models of artificial oscillating gene networks. We establish that the buffering phenomenon is realized in these system for an appropriate choice of the parameters: any given finite number of stable periodic motions of a special type, the so-called traveling waves, coexist.

  11. Stimulation of phosphatidic acid of calcium influx and cyclic GMP synthesis in neuroblastoma cells.

    PubMed

    Ohsako, S; Deguchi, T

    1981-11-10

    Phosphatidic acid added to the medium markedly elevated intracellular cyclic GMP content in cultured neuroblastoma N1E 115 cells. There was a significant elevation of cyclic GMP with 1 micrograms/ml and a maximum (70-fold) elevation with 100 micrograms/ml of phosphatidic acid. Other natural phospholipids did not increase, or increased only slightly, the cyclic GMP content in the cells. The elevation of cyclic GMP content by phosphatidic acid was absolutely dependent on extracellular calcium. Phosphatidic acid stimulated the influx of calcium into neuroblastoma cells 2- to 5-fold. The pattern of the calcium influx induced by phosphatidic acid was comparable to that of cyclic GMP elevation. The stimulation of calcium influx by phosphatidic acid was also observed in cultured heart cells, indicating that phosphatidic acid acts as a calcium ionophore or opens a specific calcium-gate in a variety of cell membranes. Treatment of neuroblastoma cells with phospholipase C increased 32Pi labeling of phosphatidic acid, stimulated the influx of calcium, and elevated the cyclic GMP content in the cells. Thus exogenous as well as endogenous phosphatidic acid stimulates the translocation of calcium across cell membranes and, as a consequence, induces the synthesis of cyclic GMP in the neuroblastoma cells.

  12. Cyclic peptide therapeutics: past, present and future.

    PubMed

    Zorzi, Alessandro; Deyle, Kaycie; Heinis, Christian

    2017-02-26

    Cyclic peptides combine several favorable properties such as good binding affinity, target selectivity and low toxicity that make them an attractive modality for the development of therapeutics. Over 40 cyclic peptide drugs are currently in clinical use and around one new cyclic peptide drug enters the market every year on average. The vast majority of clinically approved cyclic peptides are derived from natural products, such as antimicrobials or human peptide hormones. New powerful techniques based on rational design and in vitro evolution have enabled the de novo development of cyclic peptide ligands to targets for which nature does not offer solutions. A look at the cyclic peptides currently under clinical evaluation shows that several have been developed using such techniques. This new source for cyclic peptide ligands introduces a freshness to the field, and it is likely that de novo developed cyclic peptides will be in clinical use in the near future.

  13. Results on Cyclic Signal Processing Systems,

    DTIC Science & Technology

    1998-01-01

    8] Vaidyanathan, P. P. Multirate systems and filter banks , Prentice Hall, 1993. [9] Vaidyanathan, P. P., and Kirac, A. "Theory of cyclic filter ...91125 Abstract We present a state space description for cyclic LTI sys- tems which find applications in cyclic filter banks and wavelets. We also...in a unified way by using the realization matrix defined by the state space description. 1. INTRODUCTION Cyclic digital filters and filter banks

  14. Cyclic Pursuit in Three Dimensions

    DTIC Science & Technology

    2010-12-17

    A three-dimensional version of the motion camouflage pursuit 49th IEEE Conference on Decision and Control December 15-17, 2010 Hilton Atlanta Hotel ...show that Θ is a constant value on MCB(a). Proposition 4: Consider a two-particle system operating on MCB(a) according to the closed-loop mutual CB...illustrate various types of trajectories in terms of initial conditions (` and Θ) and parameter values (a+ and a−). In our planar discussion of cyclic

  15. Plant cyclic nucleotide signalling: facts and fiction.

    PubMed

    Martinez-Atienza, Juliana; Van Ingelgem, Carl; Roef, Luc; Maathuis, Frans Jm

    2007-11-01

    The presence of the cyclic nucleotides 3',5'-cyclic adenyl monophosphate (cAMP) and 3',5'-cyclic guanyl monophosphate (cGMP) in plants is now generally accepted. In addition, cAMP and cGMP have been implicated in the regulation of important plant processes such as stomatal functioning, monovalent and divalent cation fluxes, chloroplast development, gibberellic acid signalling, pathogen response and gene transcription. However, very little is known regarding the components of cyclic nucleotide signalling in plants. In this addendum, the evidence for specific mechanisms of plant cyclic nucleotide signalling is evaluated and discussed.

  16. Supramolecular nesting of cyclic polymers.

    PubMed

    Kondratuk, Dmitry V; Perdigão, Luís M A; Esmail, Ayad M S; O'Shea, James N; Beton, Peter H; Anderson, Harry L

    2015-04-01

    Advances in template-directed synthesis make it possible to create artificial molecules with protein-like dimensions, directly from simple components. These synthetic macromolecules have a proclivity for self-organization that is reminiscent of biopolymers. Here, we report the synthesis of monodisperse cyclic porphyrin polymers, with diameters of up to 21 nm (750 C–C bonds). The ratio of the intrinsic viscosities for cyclic and linear topologies is 0.72, indicating that these polymers behave as almost ideal flexible chains in solution. When deposited on gold surfaces, the cyclic polymers display a new mode of two-dimensional supramolecular organization, combining encapsulation and nesting; one nanoring adopts a near-circular conformation, thus allowing a second nanoring to be captured within its perimeter, in a tightly folded conformation. Scanning tunnelling microscopy reveals that nesting occurs in combination with stacking when nanorings are deposited under vacuum, whereas when they are deposited directly from solution under ambient conditions there is stacking or nesting, but not a combination of both.

  17. Cyclic Deformation in Metallic Glasses.

    PubMed

    Sha, Z D; Qu, S X; Liu, Z S; Wang, T J; Gao, H

    2015-10-14

    Despite the utmost importance and decades of experimental studies on fatigue in metallic glasses (MGs), there has been so far little or no atomic-level understanding of the mechanisms involved. Here we perform molecular dynamics simulations of tension-compression fatigue in Cu50Zr50 MGs under strain-controlled cyclic loading. It is shown that the shear band (SB) initiation under cyclic loading is distinctly different from that under monotonic loading. Under cyclic loading, SB initiation takes place when aggregates of shear transformation zones (STZs) accumulating at the MG surface reach a critical size comparable to the SB width, and the accumulation of STZs follows a power law with rate depending on the applied strain. It is further shown that almost the entire fatigue life of nanoscale MGs under low cycle fatigue is spent in the SB-initiation stage, similar to that of crystalline materials. Furthermore, a qualitative investigation of the effect of cycling frequency on the fatigue behavior of MGs suggests that higher cycling frequency leads to more cycles to failure. The present study sheds light on the fundamental fatigue mechanisms of MGs that could be useful in developing strategies for their engineering applications.

  18. Cyclic modular beta-sheets.

    PubMed

    Woods, R Jeremy; Brower, Justin O; Castellanos, Elena; Hashemzadeh, Mehrnoosh; Khakshoor, Omid; Russu, Wade A; Nowick, James S

    2007-03-07

    The development of peptide beta-hairpins is problematic, because folding depends on the amino acid sequence and changes to the sequence can significantly decrease folding. Robust beta-hairpins that can tolerate such changes are attractive tools for studying interactions involving protein beta-sheets and developing inhibitors of these interactions. This paper introduces a new class of peptide models of protein beta-sheets that addresses the problem of separating folding from the sequence. These model beta-sheets are macrocyclic peptides that fold in water to present a pentapeptide beta-strand along one edge; the other edge contains the tripeptide beta-strand mimic Hao [JACS 2000, 122, 7654] and two additional amino acids. The pentapeptide and Hao-containing peptide strands are connected by two delta-linked ornithine (deltaOrn) turns [JACS 2003, 125, 876]. Each deltaOrn turn contains a free alpha-amino group that permits the linking of individual modules to form divalent beta-sheets. These "cyclic modular beta-sheets" are synthesized by standard solid-phase peptide synthesis of a linear precursor followed by solution-phase cyclization. Eight cyclic modular beta-sheets 1a-1h containing sequences based on beta-amyloid and macrophage inflammatory protein 2 were synthesized and characterized by 1H NMR. Linked cyclic modular beta-sheet 2, which contains two modules of 1b, was also synthesized and characterized. 1H NMR studies show downfield alpha-proton chemical shifts, deltaOrn delta-proton magnetic anisotropy, and NOE cross-peaks that establish all compounds but 1c and 1g to be moderately or well folded into a conformation that resembles a beta-sheet. Pulsed-field gradient NMR diffusion experiments show little or no self-association at low (

  19. Detection of gamma-irradiation effect on DNA and protein using magnetic sensor and cyclic voltammetry.

    PubMed

    Park, Duck-Gun; Song, Hoon; Kishore, M B; Vértesy, G; Lee, Duk-Hyun

    2013-11-01

    In this study, a magnetic sensor utilizing Planar Hall Resistance (PHR) and cyclic Voltammetry (CV) for detecting the radiation effect was fabricated. Specifically, we applied in parallel a PHR sensor and CV device to monitor the irradiation effect on DNA and protein respectively. Through parallel measurements, we demonstrated that the PHR sensor and CV are sensitive enough to measure irradiation effect. The PHR voltage decreased by magnetic nanobead labeled DNA was slightly recovered after gamma ray irradiation. The behavior of cdk inhibitor protein p21 having a sandwich structure of Au/protein G/Ab/Ag/Ab was checked by monitoring the cyclic Voltammetry signal in analyzing the gamma ray irradiation effect.

  20. Mental Labels and Tattoos

    ERIC Educational Resources Information Center

    Hyatt, I. Ralph

    1977-01-01

    Discusses the ease with which mental labels become imprinted in our system, six basic axioms for maintaining negative mental tattoos, and psychological processes for eliminating mental tattoos and labels. (RK)

  1. Pesticide Labeling Questions & Answers

    EPA Pesticide Factsheets

    Pesticide manufacturers, applicators, state regulatory agencies, and other stakeholders raise questions or issues about pesticide labels. The questions on this page are those that apply to multiple products or address inconsistencies among product labels.

  2. Soil Fumigant Labels - Chloropicrin

    EPA Pesticide Factsheets

    Search by EPA registration number, product name, or company name, and follow the link to the Pesticide Product Label System (PPLS) for details on each fumigant. Updated labels include new safety requirements for buffer zones and related measures.

  3. Soil Fumigant Labels - Dazomet

    EPA Pesticide Factsheets

    Updated labels include new safety requirements for buffer zones and related measures. Find information from the Pesticide Product Labeling System (PPLS) for products such as Basamid G, manufactured by Amvac.

  4. Mental Labels and Tattoos

    ERIC Educational Resources Information Center

    Hyatt, I. Ralph

    1977-01-01

    Discusses the ease with which mental labels become imprinted in our system, six basic axioms for maintaining negative mental tattoos, and psychological processes for eliminating mental tattoos and labels. (RK)

  5. Soil Fumigant Labels

    EPA Pesticide Factsheets

    The 2012 updated pesticide labels include new safety requirements for buffer zones and related measures. Find labels for each different type of fumigant: chloropicrin, dazomet, dimethyl disulfide, metam sodium/potassium, and methyl bromide.

  6. Electronic Submission of Labels

    EPA Pesticide Factsheets

    Pesticide registrants can provide draft and final labels to EPA electronically for our review as part of the pesticide registration process. The electronic submission of labels by registrants is voluntary but strongly encouraged.

  7. The Labelling of Chemicals.

    ERIC Educational Resources Information Center

    Education in Science, 1979

    1979-01-01

    Describes the impact on chemistry laboratories and teachers in the United Kingdom of the Packaging and Labelling of Dangerous Substances Regulations 1978. These regulations require suppliers to label containers in particular ways. (HM)

  8. Semiotic labelled deductive systems

    SciTech Connect

    Nossum, R.T.

    1996-12-31

    We review the class of Semiotic Models put forward by Pospelov, as well as the Labelled Deductive Systems developed by Gabbay, and construct an embedding of Semiotic Models into Labelled Deductive Systems.

  9. Label Review Training: Module 1: Label Basics, Page 16

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about the importance of labels and the role in enforcement.

  10. Label Review Training: Module 1: Label Basics, Page 14

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about positive effects from proper labeling.

  11. Label Review Training: Module 1: Label Basics, Page 15

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about the consequences of improper labeling.

  12. Label Review Training: Module 1: Label Basics, Page 21

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about types of labels.

  13. Label Review Training: Module 1: Label Basics, Page 19

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. This section covers supplemental distributor labeling.

  14. Label Review Training: Module 1: Label Basics, Page 17

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. See an overview of the importance of labels.

  15. Label Review Training: Module 1: Label Basics, Page 22

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about what labels require review.

  16. Label Review Training: Module 1: Label Basics, Page 27

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. See examples of mandatory and advisory label statements.

  17. Label Review Training: Module 1: Label Basics, Page 26

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about mandatory and advisory label statements.

  18. Label Review Training: Module 1: Label Basics, Page 24

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. This page is about which labels require review.

  19. Label Review Training: Module 1: Label Basics, Page 18

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. This section discusses the types of labels.

  20. Label Review Training: Module 1: Label Basics, Page 23

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Lists types of labels that do not require review.

  1. Advances in targeting cyclic nucleotide phosphodiesterases

    PubMed Central

    Maurice, Donald H.; Ke, Hengming; Ahmad, Faiyaz; Wang, Yousheng; Chung, Jay; Manganiello, Vincent C.

    2014-01-01

    Cyclic nucleotide phosphodiesterases (PDEs) catalyse the hydrolysis of cyclic AMP and cyclic GMP, thereby regulating the intracellular concentrations of these cyclic nucleotides, their signalling pathways and, consequently, myriad biological responses in health and disease. Currently, a small number of PDE inhibitors are used clinically for treating the pathophysiological dysregulation of cyclic nucleotide signalling in several disorders, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication and chronic obstructive pulmonary disease. However, pharmaceutical interest in PDEs has been reignited by the increasing understanding of the roles of individual PDEs in regulating the subcellular compartmentalization of specific cyclic nucleotide signalling pathways, by the structure-based design of novel specific inhibitors and by the development of more sophisticated strategies to target individual PDE variants. PMID:24687066

  2. Sample Pesticide Label for Label Review Training

    EPA Pesticide Factsheets

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment.

  3. Pesticide Product Label System

    EPA Pesticide Factsheets

    The Pesticide Product Label System (PPLS) provides a collection of pesticide product labels (Adobe PDF format) that have been approved by EPA under Section 3 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). New labels were added to PPLS on November 21, 2014. Pesticide product labels provide critical information about how to safely handle and use registered pesticide products. An approved pesticide product label represents the full content of EPAs registration decision regarding that product. Pesticide labels contain detailed information on the use, storage, and handling of a product. This information will be found on EPA stamped-approved labels and, in some cases, in subsequent related correspondence, which is also included in PPLS. You may need to review several PDF files for a single product to determine the complete current terms of registration.

  4. [Cyclic Cushing's Syndrome - rare or rarely recognized].

    PubMed

    Kiałka, Marta; Doroszewska, Katarzyna; Mrozińska, Sandra; Milewicz, Tomasz; Stochmal, Ewa

    2015-01-01

    Cyclic Cushing's syndrome is a type of Cushing's disease which is characterized by alternating periods of increasing and decreasing levels of cortisol in the blood. The diagnostic criteria for cyclic Cushing's syndrome are at least three periods of hypercortisolism alternating with at least two episodes of normal levels of serum cortisol concentration. The epidemiology, signs, symptoms, pathogenesis and treatment of cyclic Cushing's syndrome have been discussed.

  5. Cyclic Imide Dioxime: Formation and Hydrolytic Stability

    SciTech Connect

    Kang, S.O.; Vukovic, Sinisa; Custelcean, Radu; Hay, Benjamin

    2012-01-01

    Poly(acrylamidoximes) play an important role in the uranium extraction from seawater. The present work reports solution studies of simple analogs to address the formation and stability of two binding sites present in these polymers, open-chain amidoximes and cyclic imide dioximes, including: 1) conditions that maximize the formation of the cyclic form, 2) existence of a base-induced conversion from open-chain to cyclic form, and 3) degradation under acid and base conditions.

  6. Electron Impact Ion Fragmentation Pathways of Peracetylated C-glycoside Ketones Derived from Cyclic 1,3-diketones

    USDA-ARS?s Scientific Manuscript database

    Monosaccharide C-glycoside ketones have been prepared by aqueous-based Knoevenagel condensation of isotopically-labeled and unlabeled aldoses with cyclic diketones, 5,5-dimethyl-1,3-cyclohexanedione (dimedone) and 1,3-cyclohexanedione (1,3-CHD). The reaction products and their corresponding acetyla...

  7. Synthesis of chiral cyclic amines via Ir-catalyzed enantioselective hydrogenation of cyclic imines.

    PubMed

    Zhang, Ying; Kong, Duanyang; Wang, Rui; Hou, Guohua

    2017-04-05

    A highly enantioselective hydrogenation of cyclic imines for synthesis of chiral cyclic amines has been realized. With the complex of iridium and (R,R)-f-spiroPhos as the catalyst, a range of cyclic 2-aryl imines were smoothly hydrogenated under mild conditions without any additive to provide the corresponding chiral cyclic amines with excellent enantioselectivities of up to 98% ee. Moreover, this method could be successfully applied to the synthesis of (+)-(6S,10bR)-McN-4612-Z.

  8. A cyclic nucleotide-independent protein kinase in Leishmania donovani.

    PubMed Central

    Das, S; Saha, A K; Mukhopadhyay, N K; Glew, R H

    1986-01-01

    Leishmania donovani promastigotes labelled for 2 h with 32Pi incorporated radioactivity into at least 21 different proteins, as determined by SDS/polyacrylamide-gel electrophoresis. Pulse-chase studies with 32Pi demonstrated that the labelled proteins were in a dynamic state: some radiolabelled proteins rapidly disappeared and others appeared after the chase. The possibility of an ectokinase on the parasite was examined; incubation of intact parasites for 10 min at 25 degrees C in an osmotically buffered medium containing [gamma-32P]ATP, but not [alpha-32P]ATP, resulted in the labelling of 10 different protozoal proteins, presumably localized to the surface of the organism's plasma membrane. Intact promastigotes also catalysed the transfer of 32P from [gamma-32P]ATP to histones. The histone-dependent kinase was solubilized by repeated freezing and thawing, and sonication, and purified 118-fold by chromatographing the high-speed (200,000 g, 1 h) supernatant fraction on QAE-Sephadex, Sephadex G-150 and hydroxyapatite columns. The kinase eluted as a single activity peak from all three columns. The partially purified histone-dependent kinase had the following properties: pH optimum, 7.0; optimum temperature, 37 degrees C; Km for mixed calf thymus histone, 0.15 mM; Km for ATP, 0.8 mM; preferred fractionated histone acceptors, H2b greater than H4 greater than H2a greater than H3 (H1 does not serve as an acceptor); optimum activity required 10-20 mM-Mg2+; inhibited 50-80% by 0.01 mM- and 1 mM-Ca2+; activity was not stimulated by calmodulin, cyclic AMP (1 mM) or cyclic GMP (1 mM) nor inhibited by a cyclic AMP-dependent protein kinase inhibitor (50 micrograms/assay); apparent Mr 75,000, as determined by Sephadex G-150 gel filtration chromatography; phosphorylated exclusively serine residues. Protein kinase activity was low in the early exponential phase of the growth curve and increased 6-fold upon entry into the stationary phase. PMID:3030283

  9. Investigating cyclic nucleotide and cyclic dinucleotide binding to HCN channels by surface plasmon resonance.

    PubMed

    Hayoz, Sebastien; Tiwari, Purushottam B; Piszczek, Grzegorz; Üren, Aykut; Brelidze, Tinatin I

    2017-01-01

    Hyperpolarization-activated cyclic nucleotide-modulated (HCN) channels control cardiac and neuronal rhythmicity. HCN channels contain cyclic nucleotide-binding domain (CNBD) in their C-terminal region linked to the pore-forming transmembrane segment with a C-linker. The C-linker couples the conformational changes caused by the direct binding of cyclic nucleotides to the HCN pore opening. Recently, cyclic dinucleotides were shown to antagonize the effect of cyclic nucleotides in HCN4 but not in HCN2 channels. Based on the structural analysis and mutational studies it has been proposed that cyclic dinucleotides affect HCN4 channels by binding to the C-linker pocket (CLP). Here, we first show that surface plasmon resonance (SPR) can be used to accurately measure cyclic nucleotide binding affinity to the C-linker/CNBD of HCN2 and HCN4 channels. We then used SPR to investigate cyclic dinucleotide binding in HCN channels. To our surprise, we detected no binding of cyclic dinucleotides to the isolated monomeric C-linker/CNBDs of HCN4 channels with SPR. The binding of cyclic dinucleotides was further examined with isothermal calorimetry (ITC), which indicated no binding of cyclic dinucleotides to both monomeric and tetrameric C-linker/CNBDs of HCN4 channels. Taken together, our results suggest that interaction of the C-linker/CNBD with other parts of the channel is necessary for cyclic-dinucleotide binding in HCN4 channels.

  10. Nonlinear, nonbinary cyclic group codes

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1992-01-01

    New cyclic group codes of length 2(exp m) - 1 over (m - j)-bit symbols are introduced. These codes can be systematically encoded and decoded algebraically. The code rates are very close to Reed-Solomon (RS) codes and are much better than Bose-Chaudhuri-Hocquenghem (BCH) codes (a former alternative). The binary (m - j)-tuples are identified with a subgroup of the binary m-tuples which represents the field GF(2 exp m). Encoding is systematic and involves a two-stage procedure consisting of the usual linear feedback register (using the division or check polynomial) and a small table lookup. For low rates, a second shift-register encoding operation may be invoked. Decoding uses the RS error-correcting procedures for the m-tuple codes for m = 4, 5, and 6.

  11. Cell reorientation under cyclic stretching

    PubMed Central

    Livne, Ariel; Bouchbinder, Eran; Geiger, Benjamin

    2014-01-01

    Mechanical cues from the extracellular microenvironment play a central role in regulating the structure, function and fate of living cells. Nevertheless, the precise nature of the mechanisms and processes underlying this crucial cellular mechanosensitivity remains a fundamental open problem. Here we provide a novel framework for addressing cellular sensitivity and response to external forces by experimentally and theoretically studying one of its most striking manifestations – cell reorientation to a uniform angle in response to cyclic stretching of the underlying substrate. We first show that existing approaches are incompatible with our extensive measurements of cell reorientation. We then propose a fundamentally new theory that shows that dissipative relaxation of the cell’s passively-stored, two-dimensional, elastic energy to its minimum actively drives the reorientation process. Our theory is in excellent quantitative agreement with the complete temporal reorientation dynamics of individual cells, measured over a wide range of experimental conditions, thus elucidating a basic aspect of mechanosensitivity. PMID:24875391

  12. Metal dihalide photodissociation cyclic laser

    SciTech Connect

    Celto, J.E.; Schimitschek, E.J.; Trias, J.A.

    1980-10-21

    A pulsed laser produces emitted laser energy by photodissociation of metal dihalide and cyclic recombination. A metal dihalide selected from sub-group ii-b of the periodic table of elements is contained within an elongated sealed enclosure. Ultraviolet photons supplied from another laser employed as an excitation pump causes dissociation of the metal dihalide for achieving the ultimate laser action. An inert buffer gas is included within the enclosure for aiding photon energy transfer uniformity and to provide vibrational relaxation of the lasing medium in its electronic states. Two reflective surfaces, one of which is only partially reflective, are aligned with the principal axis of the laser assembly for producing an optical resonator for the emitted laser energy.

  13. A Cyclic Universe Numerically Realized

    NASA Astrophysics Data System (ADS)

    Duhe, William; Biswas, Tirthbar

    2013-04-01

    A unique way of realizing inflation has been proposed recently in the context of cyclic cosmology where the universe grows by a constant factor in each cycle. This leads to an overall exponential growth over many cycles. In a given cycle such a growth is possible if, for instance, ``heavy particles'' can decay into radiation (photons) leading to an increase in entropy. However, to sustain this mechanism over successive cycles, it is crucial to reproduce the heavy particles back through quantum scattering processes and re-establish thermal equilibrium between all the species. We attempt to prove the viability of a ``multiple bang'' scenario to produce known cosmological data as well as use it to predict fluctuations in the upcoming higher resolution plank telescope data. This paradigm opens doors for new investigations into the principles surrounding the content and origin of the universe.

  14. Cyclic metabolites: chemical and biological considerations.

    PubMed

    Erve, John C L

    2008-02-01

    Metabolism of xenobiotics can sometimes generate cyclic metabolites. Such metabolites are usually the result of intramolecular reactions occurring within a primary or secondary metabolite and this chemistry may lead to unexpected structures. Intramolecular chemistry is often driven by nucleophilic groups reacting with electrophilic atoms, often carbon, although radical processes also occur. Conjugation of xenobiotics or their metabolites with endogenous thiols, such as glutathione or cysteine, introduce a reactive amino group that can lead to the formation of cyclic structures. Less common than chemically driven cyclizations are enzymatically mediated ring-closures, although this may reflect our incomplete recognition of enzymatic involvement in this step of cyclic metabolite formation. While some cyclic metabolites are biologically inactive, others are biologically active. Thus, a cyclic metabolite may display desirable pharmacology, or, contribute to toxicology. When a cyclic metabolite is identified, it is important to consider the possibility that it is an artifact, i.e. metabonate, that was formed during processing of the sample, for example, through degradation or by chemical reactions with other components present in the matrix. From a medicinal chemistry perspective, a cyclic metabolite with a different chemical scaffold from the parent structure may lead to a new series of structurally novel, biologically active molecules with the same, or different, pharmacology from the parent. This review will cover a selection of cyclic metabolites from a mechanistic point of view, and when possible, discuss their biological relevance.

  15. Enantioselective Conjugate Allylation of Cyclic Enones

    PubMed Central

    Taber, Douglass F.; Gerstenhaber, David A.; Berry, James F.

    2011-01-01

    Enantioselective organocatalytic 1,2-allylation of a cyclic enone followed by anionic oxy-Cope rearrangement delivered the ketone as a mixture of diastereomers. This appears to be a general method for the net enantioselective conjugate allylation of cyclic enones. PMID:21830779

  16. Cyclic Linearization and Island Repair in Sluicing

    ERIC Educational Resources Information Center

    Qiu, Chunan

    2009-01-01

    Cyclic Linearization is adopted to account for the island repair of Sluicing in English. The extraction of wh-phrase out of certain islands undergoes non-successive-cyclic movement, which yields conflicting ordering statements. The derivation can be rescued by deleting all ordering statements in IP, including those conflicting ones. Two arguments…

  17. Cyclic homology for Hom-associative algebras

    NASA Astrophysics Data System (ADS)

    Hassanzadeh, Mohammad; Shapiro, Ilya; Sütlü, Serkan

    2015-12-01

    In the present paper we investigate the noncommutative geometry of a class of algebras, called the Hom-associative algebras, whose associativity is twisted by a homomorphism. We define the Hochschild, cyclic, and periodic cyclic homology and cohomology for this class of algebras generalizing these theories from the associative to the Hom-associative setting.

  18. Modular arithmetic weight and cyclic shifting.

    NASA Technical Reports Server (NTRS)

    Hartman, W. F.

    1972-01-01

    This note shows that the modular arithmetic weight of an integer is invariant to the cyclic shifts of its radix-2 form. This result leads to a reduced search for the minimum weight codeword in a cyclic AN-code as well as to a better understanding of previous work.

  19. Cyclic malyl anthocyanins in Dianthus caryophyllus.

    PubMed

    Nakayama, M; Koshioka, M; Yoshida, H; Kan, Y; Fukui, Y; Koike, A; Yamaguchi, M

    2000-12-01

    3,5-Di-O-(beta-glucopyranosyl) pelargonidin 6''-O-4,6'''-O-1-cyclic malate and a previously reported cyanidin equivalent, 3,5-di-O-(beta-glucopyranosyl) cyanidin 6''-O-4,6'''-O-1-cyclic malate were identified from petals of deep pink and red-purple flower cultivars of Dianthus caryophyllus, respectively.

  20. Toward structure prediction of cyclic peptides.

    PubMed

    Yu, Hongtao; Lin, Yu-Shan

    2015-02-14

    Cyclic peptides are a promising class of molecules that can be used to target specific protein-protein interactions. A computational method to accurately predict their structures would substantially advance the development of cyclic peptides as modulators of protein-protein interactions. Here, we develop a computational method that integrates bias-exchange metadynamics simulations, a Boltzmann reweighting scheme, dihedral principal component analysis and a modified density peak-based cluster analysis to provide a converged structural description for cyclic peptides. Using this method, we evaluate the performance of a number of popular protein force fields on a model cyclic peptide. All the tested force fields seem to over-stabilize the α-helix and PPII/β regions in the Ramachandran plot, commonly populated by linear peptides and proteins. Our findings suggest that re-parameterization of a force field that well describes the full Ramachandran plot is necessary to accurately model cyclic peptides.

  1. Ribosomally encoded cyclic peptide toxins from mushrooms.

    PubMed

    Walton, Jonathan D; Luo, Hong; Hallen-Adams, Heather

    2012-01-01

    The cyclic peptide toxins of poisonous Amanita mushrooms are chemically unique among known natural products. Furthermore, they differ from other fungal cyclic peptides in being synthesized on ribosomes instead of by nonribosomal peptide synthetases. Because of their novel structures and biogenic origins, elucidation of the biosynthetic pathway of the Amanita cyclic peptides presents both challenges and opportunities. In particular, a full understanding of the pathway should lead to the ability to direct synthesis of a large number of novel cyclic peptides based on the Amanita toxin scaffold by genetic engineering of the encoding genes. Here, we highlight some of the principal methods for working with the Amanita cyclic peptides and the known steps in their biosynthesis.

  2. Modeling interfacial charge transport of quantum dots using cyclic voltammetry

    NASA Astrophysics Data System (ADS)

    Tobias, Andrew K.; Jones, Marcus

    2011-10-01

    Quantum dot applications are numerous and range from photovoltaic devices and lasers, to bio labeling. Complexities in the electronic band structure of quantum dots create the necessity for analysis techniques that can accurately and reproducibly provide their absolute band energies. Cyclic voltammetry (CV) is a novel candidate for these studies and has the potential to become a useful tool in engineering new nanocrystal technology, by providing information necessary for predicting and modeling interfacial charge transfer to and from quantum dots. Advancing from previous reports of nanocrystal CV, a carbon paste electrode was utilized in an attempt to increase measured current by ensuring intimate contact between nanocrystals and the electrode. Our goal was to investigate band energies and model nanocrystal-molecule electron transfer systems.

  3. Labeling of Patient Specimens

    DTIC Science & Technology

    2011-01-26

    printers in each clinic to print labels .JDI Capt Cutter Research compatible printer, Cost, Time Frame Develop standard training for all clinics...Standardize label content, automate with inkless printers once process is proven c . Place visual reminders for providers and support staff 2. Event

  4. Labeling and Delinquency.

    ERIC Educational Resources Information Center

    Adams, Mike S.; Robertson, Craig T.; Gray-Ray, Phyllis; Ray, Melvin C.

    2003-01-01

    Index comprised of six contrasting descriptive adjectives was used to measure incarcerated youths' perceived negative labeling from the perspective of parents, teachers, and peers. Results provided partial support for hypothesis that juveniles who choose a greater number of negative labels will report more frequent delinquent involvement. Labeling…

  5. Labeling and Delinquency.

    ERIC Educational Resources Information Center

    Adams, Mike S.; Robertson, Craig T.; Gray-Ray, Phyllis; Ray, Melvin C.

    2003-01-01

    Index comprised of six contrasting descriptive adjectives was used to measure incarcerated youths' perceived negative labeling from the perspective of parents, teachers, and peers. Results provided partial support for hypothesis that juveniles who choose a greater number of negative labels will report more frequent delinquent involvement. Labeling…

  6. The topology of metabolic isotope labeling networks.

    PubMed

    Weitzel, Michael; Wiechert, Wolfgang; Nöh, Katharina

    2007-08-29

    Metabolic Flux Analysis (MFA) based on isotope labeling experiments (ILEs) is a widely established tool for determining fluxes in metabolic pathways. Isotope labeling networks (ILNs) contain all essential information required to describe the flow of labeled material in an ILE. Whereas recent experimental progress paves the way for high-throughput MFA, large network investigations and exact statistical methods, these developments are still limited by the poor performance of computational routines used for the evaluation and design of ILEs. In this context, the global analysis of ILN topology turns out to be a clue for realizing large speedup factors in all required computational procedures. With a strong focus on the speedup of algorithms the topology of ILNs is investigated using graph theoretic concepts and algorithms. A rigorous determination of all cyclic and isomorphic subnetworks, accompanied by the global analysis of ILN connectivity is performed. Particularly, it is proven that ILNs always brake up into a large number of small strongly connected components (SCCs) and, moreover, there are natural isomorphisms between many of these SCCs. All presented techniques are universal, i.e. they do not require special assumptions on the network structure, bidirectionality of fluxes, measurement configuration, or label input. The general results are exemplified with a practically relevant metabolic network which describes the central metabolism of E. coli comprising 10390 isotopomer pools. Exploiting the topological features of ILNs leads to a significant speedup of all universal algorithms for ILE evaluation. It is proven in theory and exemplified with the E. coli example that a speedup factor of about 1000 compared to standard algorithms is achieved. This widely opens the door for new high performance algorithms suitable for high throughput applications and large ILNs. Moreover, for the first time the global topological analysis of ILNs allows to comprehensively

  7. Government perspective: food labeling.

    PubMed

    Philipson, Tomas

    2005-07-01

    The Food and Drug Administration acknowledges the severity of the obesity epidemic. The Food and Drug Administration recognizes the importance of food labeling as a vehicle for dietary messages and, thus, enforces stringent guidelines to maintain the integrity of the food label. As food labels await another upgrade to make them more effective and easier to understand, the Food and Drug Administration considers what information will be most useful for consumers to make healthy choices. The causal relationship between food labels and subsequent diet choice is not well understood; more research in this area is needed. The Commissioner of the Food and Drug Administration has recently appointed an Obesity Working Group to develop proposals on pertinent topics of obesity, including the role of food labeling as a dietary guide.

  8. Mining Multi-label Data

    NASA Astrophysics Data System (ADS)

    Tsoumakas, Grigorios; Katakis, Ioannis; Vlahavas, Ioannis

    A large body of research in supervised learning deals with the analysis of single-label data, where training examples are associated with a single label λ from a set of disjoint labels L. However, training examples in several application domains are often associated with a set of labels Y ⊆ L. Such data are called multi-label.

  9. Mixed Strategies in cyclic competition

    NASA Astrophysics Data System (ADS)

    Intoy, Ben; Pleimling, Michel

    2015-03-01

    Physicists have been using evolutionary game theory to model and simulate cyclically competing species, with applications to lizard mating strategies and competing bacterial strains. However these models assume that each agent plays the same strategy, which is called a pure strategy in game theory, until they are beaten by a better strategy which they immediately adopt. We relax this constraint of an agent playing a single strategy by instead letting the agent pick its strategy randomly from a probability distribution, which is called a mixed strategy in game theory. This scheme is very similar to multiple occupancy models seen in the literature, the major difference being that interactions happen between sites rather than within them. Choosing strategies out of a distribution also has applications to economic/social systems such as the public goods game. We simulate a model of mixed strategy and cylic competition on a one-dimensional lattice with three and four strategies and find interesting spatial and stability properties depending on how discretized the choice of strategy is for the agents. This work is supported by the US National Science Foundation through Grant DMR-1205309.

  10. Label Review Training: Module 1: Label Basics, Page 29

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. This page is a quiz on Module 1.

  11. Label Review Training: Module 1: Label Basics, Page 25

    EPA Pesticide Factsheets

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review: clarity, accuracy, consistency with EPA policy, and enforceability.

  12. Asymmetric cyclic evolution in polymerised cosmology

    SciTech Connect

    Hrycyna, Orest; Mielczarek, Jakub; Szydłowski, Marek E-mail: jakub.mielczarek@uj.edu.pl

    2009-12-01

    The dynamical systems methods are used to study evolution of the polymerised scalar field cosmologies with the cosmological constant. We have found all evolutional paths admissible for all initial conditions on the two-dimensional phase space. We have shown that the cyclic solutions are generic. The exact solution for polymerised cosmology is also obtained. Two basic cases are investigated, the polymerised scalar field and the polymerised gravitational and scalar field part. In the former the division on the cyclic and non-cyclic behaviour is established following the sign of the cosmological constant. The value of the cosmological constant is upper bounded purely from the dynamical setting.

  13. Soil Fumigant Labels - Methyl Bromide

    EPA Pesticide Factsheets

    Search soil fumigant pesticide labels by EPA registration number, product name, or company, and follow the link to The Pesticide Product Label System (PPLS) for details. Updated labels include new safety requirements for buffer zones and related measures.

  14. Off-Label Drug Use

    MedlinePlus

    ... their drugs for off-label uses. Off-label marketing is very different from off-label use. Why ... Employment Become a Supplier Report Fraud or Abuse Global Health ACS CAN Sign Up for Email Policies ...

  15. Capacitive label reader

    DOEpatents

    Arlowe, H.D.

    1983-07-15

    A capacitive label reader includes an outer ring transmitting portion, an inner ring transmitting portion, and a plurality of insulated receiving portions. A label is the mirror-image of the reader except that identifying portions corresponding to the receiving portions are insulated from only one of two coupling elements. Positive and negative pulses applied, respectively, to the two transmitting rings biased a CMOS shift register positively to either a 1 or 0 condition. The output of the CMOS may be read as an indication of the label.

  16. Capacitive label reader

    DOEpatents

    Arlowe, H.D.

    1985-11-12

    A capacitive label reader includes an outer ring transmitting portion, an inner ring transmitting portion, and a plurality of insulated receiving portions. A label is the mirror-image of the reader except that identifying portions corresponding to the receiving portions are insulated from only one of two coupling elements. Positive and negative pulses applied, respectively, to the two transmitting rings biased a CMOS shift register positively to either a 1 or 0 condition. The output of the CMOS may be read as an indication of the label. 5 figs.

  17. Capacitive label reader

    DOEpatents

    Arlowe, H. Duane

    1985-01-01

    A capacitive label reader includes an outer ring transmitting portion, an inner ring transmitting portion, and a plurality of insulated receiving portions. A label is the mirror-image of the reader except that identifying portions corresponding to the receiving portions are insulated from only one of two coupling elements. Positive and negative pulses applied, respectively, to the two transmitting rings biased a CMOS shift register positively to either a 1 or 0 condition. The output of the CMOS may be read as an indication of the label.

  18. Cyclic hardening in bundled actin networks.

    PubMed

    Schmoller, K M; Fernández, P; Arevalo, R C; Blair, D L; Bausch, A R

    2010-01-01

    Nonlinear deformations can irreversibly alter the mechanical properties of materials. Most soft materials, such as rubber and living tissues, display pronounced softening when cyclically deformed. Here we show that, in contrast, reconstituted networks of crosslinked, bundled actin filaments harden when subject to cyclical shear. As a consequence, they exhibit a mechano-memory where a significant stress barrier is generated at the maximum of the cyclic shear strain. This unique response is crucially determined by the network architecture: at lower crosslinker concentrations networks do not harden, but soften showing the classic Mullins effect known from rubber-like materials. By simultaneously performing macrorheology and confocal microscopy, we show that cyclic shearing results in structural reorganization of the network constituents such that the maximum applied strain is encoded into the network architecture.

  19. Parallel architectures for computing cyclic convolutions

    NASA Technical Reports Server (NTRS)

    Yeh, C.-S.; Reed, I. S.; Truong, T. K.

    1983-01-01

    In the paper two parallel architectural structures are developed to compute one-dimensional cyclic convolutions. The first structure is based on the Chinese remainder theorem and Kung's pipelined array. The second structure is a direct mapping from the mathematical definition of a cyclic convolution to a computational architecture. To compute a d-point cyclic convolution the first structure needs d/2 inner product cells, while the second structure and Kung's linear array require d cells. However, to compute a cyclic convolution, the second structure requires less time than both the first structure and Kung's linear array. Another application of the second structure is to multiply a Toeplitz matrix by a vector. A table is listed to compare these two structures and Kung's linear array. Both structures are simple and regular and are therefore suitable for VLSI implementation.

  20. Parallel architectures for computing cyclic convolutions

    NASA Technical Reports Server (NTRS)

    Yeh, C.-S.; Reed, I. S.; Truong, T. K.

    1983-01-01

    In the paper two parallel architectural structures are developed to compute one-dimensional cyclic convolutions. The first structure is based on the Chinese remainder theorem and Kung's pipelined array. The second structure is a direct mapping from the mathematical definition of a cyclic convolution to a computational architecture. To compute a d-point cyclic convolution the first structure needs d/2 inner product cells, while the second structure and Kung's linear array require d cells. However, to compute a cyclic convolution, the second structure requires less time than both the first structure and Kung's linear array. Another application of the second structure is to multiply a Toeplitz matrix by a vector. A table is listed to compare these two structures and Kung's linear array. Both structures are simple and regular and are therefore suitable for VLSI implementation.

  1. Colour cyclic code for Brillouin distributed sensors

    NASA Astrophysics Data System (ADS)

    Le Floch, Sébastien; Sauser, Florian; Llera, Miguel; Rochat, Etienne

    2015-09-01

    For the first time, a colour cyclic coding (CCC) is theoretically and experimentally demonstrated for Brillouin optical time-domain analysis (BOTDA) distributed sensors. Compared to traditional intensity-modulated cyclic codes, the code presents an additional gain of √2 while keeping the same number of sequences as for a colour coding. A comparison with a standard BOTDA sensor is realized and validates the theoretical coding gain.

  2. Cyclic period in the CBE model

    NASA Astrophysics Data System (ADS)

    Frampton, Paul H.

    2017-08-01

    In a cyclic entropy model in which the extroverse is jettisoned at turnaround with a Come Back Empty (CBE) assumption, we address the matching of the contaction scale factor â(t) = f(tT)a(t) to the expansion scale factor a(t), where f(tT) is the ratio at turnaround of the introverse to the extroverse radii. Such matching is necessary for infinite cyclicity and fixes the CBE period at ˜ 2.6 Ty.

  3. Cyclic behaviors of amorphous shape memory polymers.

    PubMed

    Yu, Kai; Li, Hao; McClung, Amber J W; Tandon, Gyaneshwar P; Baur, Jeffery W; Qi, H Jerry

    2016-04-07

    Cyclic loading conditions are commonly encountered in the applications of shape memory polymers (SMPs), where the cyclic characteristics of the materials determine their performance during the service life, such as deformation resistance, shape recovery speed and shape recovery ratio. Recent studies indicate that in addition to the physical damage or some other irreversible softening effects, the viscoelastic nature could also be another possible reason for the degraded cyclic behavior of SMPs. In this paper, we explore in detail the influence of the viscoelastic properties on the cyclic tension and shape memory (SM) behavior of an epoxy based amorphous thermosetting polymer. Cyclic experiments were conducted first, which show that although the epoxy material does not have any visible damage or irreversible softening effect during deformation, it still exhibits obvious degradation in the cyclic tension and SM behaviors. A linear multi-branched model is utilized to assist in the prediction and understanding of the mechanical responses of amorphous SMPs. Parametric studies based on the applied model suggest that the shape memory performance can be improved by adjusting programming and recovery conditions, such as lowering the loading rate, increasing the programming temperature, and reducing the holding time.

  4. The evolution of Momordica cyclic peptides.

    PubMed

    Mahatmanto, Tunjung; Mylne, Joshua S; Poth, Aaron G; Swedberg, Joakim E; Kaas, Quentin; Schaefer, Hanno; Craik, David J

    2015-02-01

    Cyclic proteins have evolved for millions of years across all kingdoms of life to confer structural stability over their acyclic counterparts while maintaining intrinsic functional properties. Here, we show that cyclic miniproteins (or peptides) from Momordica (Cucurbitaceae) seeds evolved in species that diverged from an African ancestor around 19 Ma. The ability to achieve head-to-tail cyclization of Momordica cyclic peptides appears to have been acquired through a series of mutations in their acyclic precursor coding sequences following recent and independent gene expansion event(s). Evolutionary analysis of Momordica cyclic peptides reveals sites that are under selection, highlighting residues that are presumably constrained for maintaining their function as potent trypsin inhibitors. Molecular dynamics of Momordica cyclic peptides in complex with trypsin reveals site-specific residues involved in target binding. In a broader context, this study provides a basis for selecting Momordica species to further investigate the biosynthesis of the cyclic peptides and for constructing libraries that may be screened against evolutionarily related serine proteases implicated in human diseases. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Antimicrobial Cyclic Peptides for Plant Disease Control

    PubMed Central

    Lee, Dong Wan; Kim, Beom Seok

    2015-01-01

    Antimicrobial cyclic peptides derived from microbes bind stably with target sites, have a tolerance to hydrolysis by proteases, and a favorable degradability under field conditions, which make them an attractive proposition for use as agricultural fungicides. Antimicrobial cyclic peptides are classified according to the types of bonds within the ring structure; homodetic, heterodetic, and complex cyclic peptides, which in turn reflect diverse physicochemical features. Most antimicrobial cyclic peptides affect the integrity of the cell envelope. This is achieved through direct interaction with the cell membrane or disturbance of the cell wall and membrane component biosynthesis such as chitin, glucan, and sphingolipid. These are specific and selective targets providing reliable activity and safety for non-target organisms. Synthetic cyclic peptides produced through combinatorial chemistry offer an alternative approach to develop antimicrobials for agricultural uses. Those synthesized so far have been studied for antibacterial activity, however, the recent advancements in powerful technologies now promise to provide novel antimicrobial cyclic peptides that are yet to be discovered from natural resources. PMID:25774105

  6. Like your labels?

    PubMed

    Field, Michele

    2010-01-01

    The descriptive “conventions” used on food labels are always evolving. Today, however, the changes are so complicated (partly driven by legislation requiring disclosures about environmental impacts, health issues, and geographical provenance) that these labels more often baffle buyers than enlighten them. In a light-handed manner, the article points to how sometimes reading label language can be like deciphering runes—and how if we are familiar with the technical terms, we can find a literal meaning, but still not see the implications. The article could be ten times longer because food labels vary according to cultures—but all food-exporting cultures now take advantage of our short attention-span when faced with these texts. The question is whether less is more—and if so, in this contest for our attention, what “contestant” is voted off.

  7. Label Review Training - Resources

    EPA Pesticide Factsheets

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment.

  8. Routing and Label Space Reduction in Label Switching Networks

    NASA Astrophysics Data System (ADS)

    Solano, Fernando; Caro, Luis Fernando; Stidsen, Thomas; Papadimitriou, Dimitri

    This chapter is devoted to the analysis and modeling of some problems related to the optimal usage of the label space in label switching networks. Label space problems concerning three different technologies and architectures - namely Multi-protocol Label Switching (MPLS), Ethernet VLAN-Label Switching (ELS) and All-Optical Label Switching (AOLS) - are discussed in this chapter. Each of these cases yields to different constraints of the general label space reduction problem. We propose a generic optimization model and, then, we describe some adaptations aiming at modeling each particular case. Simulation results are briefly discussed at the end of this chapter.

  9. Measuring Cyclic Error in Laser Heterodyne Interferometers

    NASA Technical Reports Server (NTRS)

    Ryan, Daniel; Abramovici, Alexander; Zhao, Feng; Dekens, Frank; An, Xin; Azizi, Alireza; Chapsky, Jacob; Halverson, Peter

    2010-01-01

    An improved method and apparatus have been devised for measuring cyclic errors in the readouts of laser heterodyne interferometers that are configured and operated as displacement gauges. The cyclic errors arise as a consequence of mixing of spurious optical and electrical signals in beam launchers that are subsystems of such interferometers. The conventional approach to measurement of cyclic error involves phase measurements and yields values precise to within about 10 pm over air optical paths at laser wavelengths in the visible and near infrared. The present approach, which involves amplitude measurements instead of phase measurements, yields values precise to about .0.1 microns . about 100 times the precision of the conventional approach. In a displacement gauge of the type of interest here, the laser heterodyne interferometer is used to measure any change in distance along an optical axis between two corner-cube retroreflectors. One of the corner-cube retroreflectors is mounted on a piezoelectric transducer (see figure), which is used to introduce a low-frequency periodic displacement that can be measured by the gauges. The transducer is excited at a frequency of 9 Hz by a triangular waveform to generate a 9-Hz triangular-wave displacement having an amplitude of 25 microns. The displacement gives rise to both amplitude and phase modulation of the heterodyne signals in the gauges. The modulation includes cyclic error components, and the magnitude of the cyclic-error component of the phase modulation is what one needs to measure in order to determine the magnitude of the cyclic displacement error. The precision attainable in the conventional (phase measurement) approach to measuring cyclic error is limited because the phase measurements are af-

  10. The envelope-based cyclic periodogram

    NASA Astrophysics Data System (ADS)

    Borghesani, P.

    2015-06-01

    Cyclostationary analysis has proven effective in identifying signal components for diagnostic purposes. A key descriptor in this framework is the cyclic power spectrum, traditionally estimated by the averaged cyclic periodogram and the smoothed cyclic periodogram. A lengthy debate about the best estimator finally found a solution in a cornerstone work by Antoni, who proposed a unified form for the two families, thus allowing a detailed statistical study of their properties. Since then, the focus of cyclostationary research has shifted towards algorithms, in terms of computational efficiency and simplicity of implementation. Traditional algorithms have proven computationally inefficient and the sophisticated "cyclostationary" definition of these estimators slowed their spread in the industry. The only attempt to increase the computational efficiency of cyclostationary estimators is represented by the cyclic modulation spectrum. This indicator exploits the relationship between cyclostationarity and envelope analysis. The link with envelope analysis allows a leap in computational efficiency and provides a "way in" for the understanding by industrial engineers. However, the new estimator lies outside the unified form described above and an unbiased version of the indicator has not been proposed. This paper will therefore extend the analysis of envelope-based estimators of the cyclic spectrum, proposing a new approach to include them in the unified form of cyclostationary estimators. This will enable the definition of a new envelope-based algorithm and the detailed analysis of the properties of the cyclic modulation spectrum. The computational efficiency of envelope-based algorithms will be also discussed quantitatively for the first time in comparison with the averaged cyclic periodogram. Finally, the algorithms will be validated with numerical and experimental examples.

  11. Cyclic alternating ring-opening metathesis polymerization (CAROMP). Rapid access to functionalized cyclic polymers.

    PubMed

    Song, Airong; Parker, Kathlyn A; Sampson, Nicole S

    2010-09-03

    Catalysis of alternating ROMP with (H(2)IMes)Cl(2)Ru=CHPh(OiPr), the second generation Hoveyda-Grubbs catalyst, provided an entirely cyclic alternating polymer. Conditions for the cyclic AROMP were used to prepare a polymer in which one of the repeat units bore a primary alkyl chloride that was used for further elaboration.

  12. Cyclic nucleotide phosphodiesterases (PDEs): coincidence detectors acting to spatially and temporally integrate cyclic nucleotide and non-cyclic nucleotide signals.

    PubMed

    Maurice, Donald H; Wilson, Lindsay S; Rampersad, Sarah N; Hubert, Fabien; Truong, Tammy; Kaczmarek, Milosz; Brzezinska, Paulina; Freitag, Silja I; Umana, M Bibiana; Wudwud, Alie

    2014-04-01

    The cyclic nucleotide second messengers cAMP and cGMP each affect virtually all cellular processes. Although these hydrophilic small molecules readily diffuse throughout cells, it is remarkable that their ability to activate their multiple intracellular effectors is spatially and temporally selective. Studies have identified a critical role for compartmentation of the enzymes which hydrolyse and metabolically inactivate these second messengers, the PDEs (cyclic nucleotide phosphodiesterases), in this specificity. In the present article, we describe several examples from our work in which compartmentation of selected cAMP- or cGMP-hydrolysing PDEs co-ordinate selective activation of cyclic nucleotide effectors, and, as a result, selectively affect cellular functions. It is our belief that therapeutic strategies aimed at targeting PDEs within these compartments will allow greater selectivity than those directed at inhibiting these enzymes throughout the cells.

  13. Nanostructured luminescently labeled nucleic acids.

    PubMed

    Kricka, Larry J; Fortina, Paolo; Park, Jason Y

    2017-03-01

    Important and emerging trends at the interface of luminescence, nucleic acids and nanotechnology are: (i) the conventional luminescence labeling of nucleic acid nanostructures (e.g. DNA tetrahedron); (ii) the labeling of bulk nucleic acids (e.g. single-stranded DNA, double-stranded DNA) with nanostructured luminescent labels (e.g. copper nanoclusters); and (iii) the labeling of nucleic acid nanostructures (e.g. origami DNA) with nanostructured luminescent labels (e.g. silver nanoclusters). This review surveys recent advances in these three different approaches to the generation of nanostructured luminescently labeled nucleic acids, and includes both direct and indirect labeling methods. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Cyclic depsipeptides as potential cancer therapeutics.

    PubMed

    Kitagaki, Jirouta; Shi, Genbin; Miyauchi, Shizuka; Murakami, Shinya; Yang, Yili

    2015-03-01

    Cyclic depsipeptides are polypeptides in which one or more amino acid is replaced by a hydroxy acid, resulting in the formation of at least one ester bond in the core ring structure. Many natural cyclic depsipeptides possessing intriguing structural and biological properties, including antitumor, antifungal, antiviral, antibacterial, anthelmintic, and anti-inflammatory activities, have been identified from fungi, plants, and marine organisms. In particular, the potent effects of cyclic depsipeptides on tumor cells have led to a number of clinical trials evaluating their potential as chemotherapeutic agents. Although many of the trials have not achieved the desired results, romidepsin (FK228), a bicyclic depsipeptide that inhibits histone deacetylase, has been shown to have clinical efficacy in patients with refractory cutaneous T-cell lymphoma and has received Food and Drug Administration approval for use in treatment. In this review, we discuss antitumor cyclic depsipeptides that have undergone clinical trials and focus on their structural features, mechanisms, potential applications in chemotherapy, and pharmacokinetic and toxicity data. The results of this study indicate that cyclic depsipeptides could be a rich source of new cancer therapeutics.

  15. Cyclic transformation of orbital angular momentum modes

    NASA Astrophysics Data System (ADS)

    Schlederer, Florian; Krenn, Mario; Fickler, Robert; Malik, Mehul; Zeilinger, Anton

    2016-04-01

    The spatial modes of photons are one realization of a QuDit, a quantum system that is described in a D-dimensional Hilbert space. In order to perform quantum information tasks with QuDits, a general class of D-dimensional unitary transformations is needed. Among these, cyclic transformations are an important special case required in many high-dimensional quantum communication protocols. In this paper, we experimentally demonstrate a cyclic transformation in the high-dimensional space of photonic orbital angular momentum (OAM). Using simple linear optical components, we show a successful four-fold cyclic transformation of OAM modes. Interestingly, our experimental setup was found by a computer algorithm. In addition to the four-cyclic transformation, the algorithm also found extensions to higher-dimensional cycles in a hybrid space of OAM and polarization. Besides being useful for quantum cryptography with QuDits, cyclic transformations are key for the experimental production of high-dimensional maximally entangled Bell-states.

  16. Induction of an Extracellular Cyclic Nucleotide Phosphodiesterase as an Accessory Ribonucleolytic Activity during Phosphate Starvation of Cultured Tomato Cells

    PubMed Central

    Abel, Steffen; Nürnberger, Thorsten; Ahnert, Volker; Krauss, Gerd-Joachim; Glund, Konrad

    2000-01-01

    During growth under conditions of phosphate limitation, suspension-cultured cells of tomato (Lycopersicon esculentum Mill.) secrete phosphodiesterase activity in a similar fashion to phosphate starvation-inducible ribonuclease (RNase LE), a cyclizing endoribonuclease that generates 2′:3′-cyclic nucleoside monophosphates (NMP) as its major monomeric products (T. Nürnberger, S. Abel, W. Jost, K. Glund [1990] Plant Physiol 92: 970–976). Tomato extracellular phosphodiesterase was purified to homogeneity from the spent culture medium of phosphate-starved cells and was characterized as a cyclic nucleotide phosphodiesterase. The purified enzyme has a molecular mass of 70 kD, a pH optimum of 6.2, and an isoelectric point of 8.1. The phosphodiesterase preparation is free of any detectable deoxyribonuclease, ribonuclease, and nucleotidase activity. Tomato extracellular phosphodiesterase is insensitive to EDTA and hydrolyzes with no apparent base specificity 2′:3′-cyclic NMP to 3′-NMP and the 3′:5′-cyclic isomers to a mixture of 3′-NMP and 5′-NMP. Specific activities of the enzyme are 2-fold higher for 2′:3′-cyclic NMP than for 3′:5′-cyclic isomers. Analysis of monomeric products of sequential RNA hydrolysis with purified RNase LE, purified extracellular phosphodiesterase, and cleared −Pi culture medium as a source of 3′-nucleotidase activity indicates that cyclic nucleotide phosphodiesterase functions as an accessory ribonucleolytic activity that effectively hydrolyzes primary products of RNase LE to substrates for phosphate-starvation-inducible phosphomonoesterases. Biosynthetical labeling of cyclic nucleotide phopshodiesterase upon phosphate starvation suggests de novo synthesis and secretion of a set of nucleolytic enzymes for scavenging phosphate from extracellular RNA substrates. PMID:10677447

  17. 21 CFR 820.120 - Device labeling.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... QUALITY SYSTEM REGULATION Labeling and Packaging Control § 820.120 Device labeling. Each manufacturer shall establish and maintain procedures to control labeling activities. (a) Label integrity. Labels... accuracy including, where applicable, the correct expiration date, control number, storage instructions...

  18. Binary and ternary cocrystals of sulfa drug acetazolamide with pyridine carboxamides and cyclic amides.

    PubMed

    Bolla, Geetha; Nangia, Ashwini

    2016-03-01

    A novel design strategy for cocrystals of a sulfonamide drug with pyridine carboxamides and cyclic amides is developed based on synthon identification as well as size and shape match of coformers. Binary adducts of acetazolamide (ACZ) with lactams (valerolactam and caprolactam, VLM, CPR), cyclic amides (2-pyridone, labeled as 2HP and its derivatives MeHP, OMeHP) and pyridine amides (nicotinamide and picolinamide, NAM, PAM) were obtained by manual grinding, and their single crystals by solution crystallization. The heterosynthons in the binary cocrystals of ACZ with these coformers suggested a ternary combination for ACZ with pyridone and nicotinamide. Novel supramolecular synthons of ACZ with lactams and pyridine carboxamides are reported together with binary and ternary cocrystals for a sulfonamide drug. This crystal engineering study resulted in the first ternary cocrystal of acetazolamide with amide coformers, ACZ-NAM-2HP (1:1:1).

  19. Binary and ternary cocrystals of sulfa drug acetazolamide with pyridine carboxamides and cyclic amides

    PubMed Central

    Bolla, Geetha; Nangia, Ashwini

    2016-01-01

    A novel design strategy for cocrystals of a sulfonamide drug with pyridine carboxamides and cyclic amides is developed based on synthon identification as well as size and shape match of coformers. Binary adducts of acetazolamide (ACZ) with lactams (valerolactam and caprolactam, VLM, CPR), cyclic amides (2-pyridone, labeled as 2HP and its derivatives MeHP, OMeHP) and pyridine amides (nicotinamide and picolinamide, NAM, PAM) were obtained by manual grinding, and their single crystals by solution crystallization. The heterosynthons in the binary cocrystals of ACZ with these coformers suggested a ternary combination for ACZ with pyridone and nicotinamide. Novel supramolecular synthons of ACZ with lactams and pyridine carboxamides are reported together with binary and ternary cocrystals for a sulfonamide drug. This crystal engineering study resulted in the first ternary cocrystal of acetazolamide with amide coformers, ACZ–NAM–2HP (1:1:1). PMID:27006778

  20. Cyclic cholecystokinin analogues with high selectivity for central receptors.

    PubMed Central

    Charpentier, B; Pelaprat, D; Durieux, C; Dor, A; Reibaud, M; Blanchard, J C; Roques, B P

    1988-01-01

    Taking as a model the N-terminal folding of the cholecystokinin tyrosine-sulfated octapeptide [CCK-8; Asp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2] deduced from conformational studies, two cyclic cholecystokinin (CCK) analogues were synthesized by conventional peptide synthesis: Boc-D-Asp-Tyr(SO3H)-Ahx-D-Lys-Trp-Ahx-Asp-Phe-NH2 [compound I (Ahx, 2-aminohexanoic acid)] and Boc-gamma-D-Glu-Tyr(SO3H)-Ahx-D-Lys-Trp-Ahx-Asp-Phe-NH2 (compound II). The binding characteristics of these peptides were investigated on brain cortex membranes and pancreatic acini of guinea pig. Compounds I and II were competitive inhibitors of [3H]Boc[Ahx28,31]CCK-(27-33) binding to central CCK receptors and showed a high degree of selectivity for these binding sites (compound I: Ki for pancreas/Ki for brain, 179; compound II: Ki for pancreas/Ki for brain, 1979). This high selectivity was associated with a high affinity for central CCK receptors (compound I: Ki, 5.1 nM; compound II: Ki, 0.49 nM). Similar affinities and selectivities were found when 125I Bolton-Hunter-labeled CCK-8 was used as a ligand. Moreover, these compounds were only weakly active in the stimulation of amylase release from guinea pig pancreatic acini (EC50 greater than 10,000 nM) and were unable to induce contractions in the guinea pig ileum (to 10(-6) M). The two cyclic CCK analogues, therefore, appear to be synthetic ligands exhibiting both high affinity and high selectivity for central CCK binding sites. These compounds could help clarify the respective role of central and peripheral receptors for various CCK-8-induced pharmacological effects. PMID:3162318

  1. The nature of solar cyclicity. I

    NASA Astrophysics Data System (ADS)

    Romanchuk, P. R.

    1981-02-01

    The report contains a critical survey of work devoted to the study of the nature of solar cyclicity. The inconsistency of the representation of cyclic curves using a frequency spectrum is indicated. The useful contribution of the ideas of Wolf, Newcomb, and Waldmeier to the solution of the problem is noted. Data are cited in favor of the theory of the tidal nature of solar cyclicity developed by the author, which also takes into account the ideas of the above-mentioned authors: the continuous paired and single tidal actions of the planets and the resonance character of this action, thanks to which the approximately 10-year period of action of Jupiter and Saturn is transformed into the 11-year activity cycle.

  2. Evaluation of homogeneous electrocatalysts by cyclic voltammetry.

    PubMed

    Rountree, Eric S; McCarthy, Brian D; Eisenhart, Thomas T; Dempsey, Jillian L

    2014-10-06

    The pursuit of solar fuels has motivated extensive research on molecular electrocatalysts capable of evolving hydrogen from protic solutions, reducing CO2, and oxidizing water. Determining accurate figures of merit for these catalysts requires the careful and appropriate application of electroanalytical techniques. This Viewpoint first briefly presents the fundamentals of cyclic voltammetry and highlights practical experimental considerations before focusing on the application of cyclic voltammetry for the characterization of electrocatalysts. Key metrics for comparing catalysts, including the overpotential (η), potential for catalysis (E(cat)), observed rate constant (k(obs)), and potential-dependent turnover frequency, are discussed. The cyclic voltammetric responses for a general electrocatalytic one-electron reduction of a substrate are presented along with methods to extract figures of merit from these data. The extension of this analysis to more complex electrocatalytic schemes, such as those responsible for H2 evolution and CO2 reduction, is then discussed.

  3. Cyclic and low temperature effects on microcircuits

    NASA Technical Reports Server (NTRS)

    Weissflug, V. A.; Sisul, E. V.

    1977-01-01

    Cyclic temperature and low temperature operating life tests, and pre-/post-life device evaluations were used to determine the degrading effects of thermal environments on microcircuit reliability. Low power transistor-transistor-logic gates and linear devices were included in each test group. Device metallization systems included aluminum metallization/aluminum wire, aluminum metallization/gold wire, and gold metallization/gold wire. Fewer than 2% electrical failures were observed during the cyclic and low temperature life tests and the post-life evaluations revealed approximately 2% bond pull failures. Reconstruction of aluminum die metallization was observed in all devices and the severity of the reconstruction appeared to be directly related to the magnitude of the temperature excursion. All types of bonds except the gold/gold bonds were weakened by exposure to repeated cyclic temperature stress.

  4. Cyclic Cocycles on Twisted Convolution Algebras

    NASA Astrophysics Data System (ADS)

    Angel, Eitan

    2013-01-01

    We give a construction of cyclic cocycles on convolution algebras twisted by gerbes over discrete translation groupoids. For proper étale groupoids, Tu and Xu (Adv Math 207(2):455-483, 2006) provide a map between the periodic cyclic cohomology of a gerbe-twisted convolution algebra and twisted cohomology groups which is similar to the construction of Mathai and Stevenson (Adv Math 200(2):303-335, 2006). When the groupoid is not proper, we cannot construct an invariant connection on the gerbe; therefore to study this algebra, we instead develop simplicial techniques to construct a simplicial curvature 3-form representing the class of the gerbe. Then by using a JLO formula we define a morphism from a simplicial complex twisted by this simplicial curvature 3-form to the mixed bicomplex computing the periodic cyclic cohomology of the twisted convolution algebras.

  5. Cyclic Oxonitriles: Stereodivergent Grignard Addition-Alkylations

    PubMed Central

    Fleming, Fraser F.; Wei, Guoqing; Zhang, Zhiyu; Steward, Omar W.

    2008-01-01

    Sequential carbonyl addition-conjugate addition of Grignard reagents to cyclic 5–7–membered oxoalkenenitriles efficiently generates cyclic magnesiated nitriles. Alkylations of these magnesiated nitriles exhibit diastereoselectivities that depend intimately on the size of the carbocyclic ring: 5-membered oxonitriles generate magnesiated nitriles whose alkylations are controlled by steric constraints whereas 6- and 7-membered oxonitriles generate internally coordinated, C-magnesiated nitriles whose alkylations are controlled by stereoelectronic effects. Reversing the alkylation selectivity of 6-membered C-magnesiated nitriles is achieved by conversion to an N-metalated nitrile in which steric, rather than electronic, effects direct the electrophile trajectory. Collectively, the conjugate addition-alkylation generates highly substituted, cyclic 5–7-membered nitriles containing three new stereocenters with selective access to diastereomers at the quaternary nitrile-bearing carbon. PMID:17567075

  6. Cyclic Polymer with Alternating Monomer Sequence.

    PubMed

    Zhu, Wen; Li, Zi; Zhao, Youliang; Zhang, Ke

    2015-11-01

    Cyclic polymers with alternating monomer sequence are synthesized for the first time based on the ring-closure strategy. Well-defined telechelic alternating polymers are synthesized by reversible addition-fragmentation chain transfer polymerization by copolymerizing the electron acceptor monomer of N-benzylmaleimide and donor monomer of styrene with a feed ratio of 1 between them. The corresponding cyclic alternating polymers are then produced by the UV-induced Diels-Alder click reaction to ring-close the linear alternating polymer precursors under highly diluted reaction solution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Cyclic entropy: An alternative to inflationary cosmology

    NASA Astrophysics Data System (ADS)

    Frampton, Paul Howard

    2015-07-01

    We address how to construct an infinitely cyclic universe model. A major consideration is to make the entropy cyclic which requires the entropy to be reset to zero in each cycle expansion → turnaround → contraction → bounce → etc. Here, we reset entropy at the turnaround by selecting the introverse (visible universe) from the extroverse which is generated by the accelerated expansion. In the model, the observed homogeneity is explained by the low entropy at the bounce. The observed flatness arises from the contraction together with the reduction in size between the expanding and contracting universe. The present flatness is predicted to be very precise.

  8. SICLOPPS cyclic peptide libraries in drug discovery.

    PubMed

    Tavassoli, Ali

    2017-02-28

    Cyclic peptide libraries have demonstrated significant potential when employed against challenging targets such as protein-protein interactions. While a variety of methods for library generation exist, genetically encoded libraries hold several advantages over their chemically synthesized counterparts; they are more readily accessible and allow straightforward hit deconvolution. One method for the intracellular generation of such libraries is split-intein circular ligation of peptides and proteins (SICLOPPS). Here we detail and discuss the deployment of SICLOPPS libraries for the identification of cyclic peptide inhibitors of a variety of targets.

  9. Microfluidic chips with reversed-phase monoliths for solid phase extraction and on-chip labeling.

    PubMed

    Nge, Pamela N; Pagaduan, Jayson V; Yu, Ming; Woolley, Adam T

    2012-10-26

    The integration of sample preparation methods into microfluidic devices provides automation necessary for achieving complete micro total analysis systems. We have developed a technique that combines on-chip sample enrichment with fluorescence labeling and purification. Polymer monoliths made from butyl methacrylate were fabricated in cyclic olefin copolymer microdevices and used for solid phase extraction. We studied the retention of fluorophores, amino acids and proteins on these columns. The retained samples were subsequently labeled with both Alexa Fluor 488 and Chromeo P503, and unreacted dye was rinsed off the column before sample elution. Additional purification was obtained from the differential retention of proteins and fluorescent labels. A linear relation between the eluted peak areas and concentrations of on-chip labeled heat shock protein 90 samples demonstrated the utility of this method for on-chip quantitation. Our fast and simple method of simultaneously concentrating and labeling samples on-chip is compatible with miniaturization and desirable for automated analysis.

  10. Mutations of PKA cyclic nucleotide-binding domains reveal novel aspects of cyclic nucleotide selectivity.

    PubMed

    Lorenz, Robin; Moon, Eui-Whan; Kim, Jeong Joo; Schmidt, Sven H; Sankaran, Banumathi; Pavlidis, Ioannis V; Kim, Choel; Herberg, Friedrich W

    2017-07-06

    Cyclic AMP and cyclic GMP are ubiquitous second messengers that regulate the activity of effector proteins in all forms of life. The main effector proteins, the 3',5'-cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) and the 3',5'-cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG), are preferentially activated by cAMP and cGMP, respectively. However, the molecular basis of this cyclic nucleotide selectivity is still not fully understood. Analysis of isolated cyclic nucleotide-binding (CNB) domains of PKA regulatory subunit type Iα (RIα) reveals that the C-terminal CNB-B has a higher cAMP affinity and selectivity than the N-terminal CNB-A. Here, we show that introducing cGMP-specific residues using site-directed mutagenesis reduces the selectivity of CNB-B, while the combination of two mutations (G316R/A336T) results in a cGMP-selective binding domain. Furthermore, introducing the corresponding mutations (T192R/A212T) into the PKA RIα CNB-A turns this domain into a highly cGMP-selective domain, underlining the importance of these contacts for achieving cGMP specificity. Binding data with the generic purine nucleotide 3',5'-cyclic inosine monophosphate (cIMP) reveal that introduced arginine residues interact with the position 6 oxygen of the nucleobase. Co-crystal structures of an isolated CNB-B G316R/A336T double mutant with either cAMP or cGMP reveal that the introduced threonine and arginine residues maintain their conserved contacts as seen in PKG I CNB-B. These results improve our understanding of cyclic nucleotide binding and the molecular basis of cyclic nucleotide specificity. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  11. A Deceiving Label?

    ERIC Educational Resources Information Center

    Lum, Lydia

    2009-01-01

    The author reports on the growing debate among educators on whether the umbrella Asian Pacific Islander label conceals disparities among Asian American students or provides political power in numbers. Nationally, experts say that support services aimed at not only Southeast Asians, but all Asian Pacific Islander students, remain scarce in higher…

  12. A Deceiving Label?

    ERIC Educational Resources Information Center

    Lum, Lydia

    2009-01-01

    The author reports on the growing debate among educators on whether the umbrella Asian Pacific Islander label conceals disparities among Asian American students or provides political power in numbers. Nationally, experts say that support services aimed at not only Southeast Asians, but all Asian Pacific Islander students, remain scarce in higher…

  13. From Labels to Opportunities

    ERIC Educational Resources Information Center

    Wolter, Deborah

    2017-01-01

    The author argues that to truly help young students who struggle with reading and writing--including those with identified disabilities or conditions that effect building literacy--teachers should avoid the approach of focusing on a student's deficits and creating labels for him or her (dyslexic, English language learner, and so on). A rush to…

  14. Photoaffinity-labeled Cytokinins

    PubMed Central

    Theiler, Jane B.; Leonard, Nelson J.; Schmitz, Ruth Y.; Skoog, Folke

    1976-01-01

    Two new azidopurine derivatives, 2-azido-N6-(Δ2-isopentenyl)adenine and 2-azido-N6-benzyladenine, have been synthesized as potential photoaffinity labels for probing cytokinin-binding sites. The preparation and the biological activity of these compounds are described. PMID:16659772

  15. The coefficient of cyclic variation: a novel statistic to measure the magnitude of cyclic variation.

    PubMed

    Fulford, Anthony Jc

    2014-01-01

    PERIODIC OR CYCLIC DATA OF KNOWN PERIODICITY ARE FREQUENTLY ENCOUNTERED IN EPIDEMIOLOGICAL AND BIOMEDICAL RESEARCH: for instance, seasonality provides a useful experiment of nature while diurnal rhythms play an important role in endocrine secretion. There is, however, little consensus on how to analysis these data and less still on how to measure association or effect size for the often complex patterns seen. A simple statistic, readily derived from Fourier regression models, provides a readily-understood measure cyclic variation in a wide variety of situations. The coefficient of cyclic variation or similar statistics derived from the variance of a Fourier series could provide a universal means of summarising the magnitude of periodic variation.

  16. Cyclic unequal error protection codes constructed from cyclic codes of composite length

    NASA Technical Reports Server (NTRS)

    Lin, Shu

    1987-01-01

    The distance structure of cyclic codes of composite length was investigated. A lower bound on the minimum distance for this class of codes is derived. In many cases, the lower bound gives the true minimum distance of a code. Then the distance structure of the direct sum of two cyclic codes of composite length were investigated. It was shown that, under certain conditions, the direct-sum code provides two levels of error correcting capability, and hence is a two-level unequal error protection (UEP) code. Finally, a class of two-level UEP cyclic direct-sum codes and a decoding algorithm for a subclass of these codes are presented.

  17. Use of forskolin to study the relationship between cyclic AMP formation and bone resorption in vitro.

    PubMed Central

    Lerner, U H; Fredholm, B B; Ransjö, M

    1986-01-01

    The effect of the adenylate cyclase activator forskolin on bone resorption and cyclic AMP accumulation was studied in an organ-culture system by using calvarial bones from 6-7-day-old mice. Forskolin caused a rapid and fully reversible increase of cyclic AMP, which was maximal after 20-30 min. The phosphodiesterase inhibitor rolipram (30 mumol/l), enhanced the cyclic AMP response to forskolin (50 mumol/l) from a net cyclic AMP response of 1234 +/- 154 pmol/bone to 2854 +/- 193 pmol/bone (mean +/- S.E.M., n = 4). The cyclic AMP level in bones treated with forskolin (30 mumol/l) was significantly increased after 24 h of culture. Forskolin, at and above 0.3 mumol/l, in the absence and the presence of rolipram (30 mumol/l), caused a dose-dependent cyclic AMP accumulation with an calculated EC50 (concentration producing half-maximal stimulation) value at 8.3 mumol/l. In 24 h cultures forskolin inhibited spontaneous and PTH (parathyroid hormone)-stimulated 45Ca release with calculated IC50 (concentration producing half-maximal inhibition) values at 1.6 and 0.6 mumol/l respectively. Forskolin significantly inhibited the release of 3H from [3H]proline-labelled bones stimulated by PTH (10 nmol/l). The inhibitory effect by forskolin on PTH-stimulated 45Ca release was significant already after 3 h of culture. In 24 h cultures forskolin (3 mumol/l) significantly inhibited 45Ca release also from bones stimulated by prostaglandin E2 (1 mumol/l) and 1 alpha-hydroxycholecalciferol (0.1 mumol/l). The inhibitory effect of forskolin on spontaneous and PTH-stimulated 45Ca release was transient. A dose-dependent stimulation of basal 45Ca release was seen in 120 h cultures, at and above 3 nmol of forskolin/l, with a calculated EC50 value at 16 nmol/l. The stimulatory effect of forskolin (1 mumol/l) could be inhibited by calcitonin (0.1 unit/ml), but was insensitive to indomethacin (1 mumol/l). Forskolin increased the release of 3H from [3H]proline-labelled bones cultured for 120 h and

  18. Label Review Training: Module 1: Label Basics, Page 7

    EPA Pesticide Factsheets

    Page 7, Label Training, Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human he

  19. Asymmetric Palladium-Catalyzed Alkene Carboamination Reactions for the Synthesis of Cyclic Sulfamides.

    PubMed

    Garlets, Zachary J; Parenti, Kaia R; Wolfe, John P

    2016-04-18

    The synthesis of cyclic sulfamides by enantioselective Pd-catalyzed alkene carboamination reactions between N-allylsulfamides and aryl or alkenyl bromides is described. High levels of asymmetric induction (up to 95:5 e.r.) are achieved using a catalyst composed of [Pd2 (dba)3 ] and (S)-Siphos-PE. Deuterium-labelling studies indicate the reactions proceed through syn-aminopalladation of the alkene and suggest that the control of syn- versus anti-aminopalladation pathways is important for asymmetric induction. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Scale invariant density perturbations from cyclic cosmology

    NASA Astrophysics Data System (ADS)

    Frampton, Paul Howard

    2016-04-01

    It is shown how quantum fluctuations of the radiation during the contraction era of a comes back empty (CBE) cyclic cosmology can provide density fluctuations which re-enter the horizon during the subsequent expansion era and at lowest order are scale invariant, in a Harrison-Zel’dovich-Peebles sense. It is necessary to be consistent with observations of large scale structure.

  1. Cyclic Cratonic Carbonates and Phanerozoic Calcite Seas.

    ERIC Educational Resources Information Center

    Wilkinson, Bruce H.

    1982-01-01

    Discusses causes of cyclicity in cratonic carbonate sequences and evidence for and potential significance of postulated primary calcite sediment components in past Paleozoic seas, outlining problems, focusing on models explaining existing data, and identifying background. Future sedimentary geologists will need to address these and related areas…

  2. Planar tetracoordinate carbons in cyclic hydrocarbons.

    PubMed

    Perez, Nancy; Heine, Thomas; Barthel, Robert; Seifert, Gotthard; Vela, Alberto; Mendez-Rojas, Miguel Angel; Merino, Gabriel

    2005-04-14

    [structure: see text] A series of cyclic hydrocarbons containing a planar tetracoordinate carbon atom is proposed. To rationalize the electronic factors contributing to the stability of these molecules, an analysis of the molecular orbitals and the induced magnetic field is presented.

  3. Cyclic Cratonic Carbonates and Phanerozoic Calcite Seas.

    ERIC Educational Resources Information Center

    Wilkinson, Bruce H.

    1982-01-01

    Discusses causes of cyclicity in cratonic carbonate sequences and evidence for and potential significance of postulated primary calcite sediment components in past Paleozoic seas, outlining problems, focusing on models explaining existing data, and identifying background. Future sedimentary geologists will need to address these and related areas…

  4. A model for cyclic mechanical reinforcement

    PubMed Central

    Li, Zhenhai; Kong, Fang; Zhu, Cheng

    2016-01-01

    Mechanical force regulates a broad range of molecular interactions in biology. Three types of counterintuitive mechanical regulation of receptor–ligand dissociation have been described. Catch bonds are strengthened by constant forces, as opposed to slip bonds that are weakened by constant forces. The phenomenon that bonds become stronger with prior application of cyclic forces is termed cyclic mechanical reinforcement (CMR). Slip and catch bonds have respectively been explained by two-state models. However, they assume fast equilibration between internal states and hence are inadequate for CMR. Here we propose a three-state model for CMR where both loading and unloading regulate the transition of bonds among the short-lived, intermediate, and long-lived state. Cyclic forces favor bonds in the long-lived state, hence greatly prolonging their lifetimes. The three-state model explains the force history effect and agrees with the experimental CMR effect of integrin α5β1–fibronectin interaction. This model helps decipher the distinctive ways by which molecular bonds are mechanically strengthened: catch bonds by constant forces and CMR by cyclic forces. The different types of mechanical regulation may enable the cell to fine tune its mechanotransduction via membrane receptors. PMID:27786286

  5. Cyclic nucleotide imaging and cardiovascular disease.

    PubMed

    Berisha, Filip; Nikolaev, Viacheslav O

    2017-02-16

    The universal second messengers cyclic nucleotides 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP) play central roles in cardiovascular function and disease. They act in discrete, functionally relevant subcellular microdomains which regulate, for example, calcium cycling and excitation-contraction coupling. Such localized cAMP and cGMP signals have been difficult to measure using conventional biochemical techniques. Recent years have witnessed the advent of live cell imaging techniques which allow visualization of these functionally relevant second messengers with unprecedented spatial and temporal resolution at cellular, subcellular and tissue levels. In this review, we discuss these new imaging techniques and give examples how they are used to visualize cAMP and cGMP in physiological and pathological settings to better understand cardiovascular function and disease. Two primary techniques include the use of Förster resonance energy transfer (FRET) based cyclic nucleotide biosensors and nanoscale scanning ion conductance microscopy (SICM). These methods can provide deep mechanistic insights into compartmentalized cAMP and cGMP signaling.

  6. Cyclic electron flow: facts and hypotheses.

    PubMed

    Finazzi, Giovanni; Johnson, Giles N

    2016-09-01

    Over the last 15 years, research into the process of cyclic electron flow in photosynthesis has seen a huge resurgence. Having been considered by some in the early 1990s as a physiologically unimportant artefact, it is now recognised as essential to normal plant growth. Here, we provide an overview of the major developments covered in this special issue of photosynthesis research.

  7. One pot solution synthesis of cyclic oligodeoxyribonucleotides.

    PubMed Central

    Capobianco, M L; Carcuro, A; Tondelli, L; Garbesi, A; Bonora, G M

    1990-01-01

    Several cyclic oligodeoxynucleotides with different base composition and size have been prepared from 5',3'-unprotected linear precursors, using a bifunctional phosphorylating reagent. The final deprotected oligomers have been characterized by 1H- and 31P-NMR. The present procedure is particularly useful for millimolar scale syntheses. PMID:2339055

  8. Strain controlled cyclic tests on miniaturized specimens

    NASA Astrophysics Data System (ADS)

    Procházka, R.; Džugan, J.

    2017-02-01

    The paper is dealing with strain controlled cyclic tests using a non-contact strain measurement based on digital image correlation techniques on proportional sizes of conventional specimens. The cyclic behaviour of 34CrNiMo6 high-strength steel was investigated on miniaturized round specimens with diameter of 2mm that were compared with specimens in accordance with ASTM E606 standards. The cycle asymmetry coefficient was R= -1. This application is intended to be used for life time assessment of in service components in future work which enables to carried out a group of mechanical tests from a limited amount of the experimental material. The attention was paid to confirm the suitability of the proposed size miniaturization geometry, testing set up and procedure. The test results obtained enabled to construct Manson-Coffin curves and assess fatigue parameters. The purpose of this study is to present differences between cyclic curves and cyclic parameters which have been evaluated based on conventional and miniaturized specimens.

  9. Effects of cyclical etidronate with alfacalcidol on lumbar bone mineral density, bone resorption, and back pain in postmenopausal women with osteoporosis.

    PubMed

    Iwamoto, Jun; Takeda, Tsuyoshi; Ichimura, Shoichi; Matsu, Kenjiro; Uzawa, Mitsuyoshi

    2003-01-01

    The purpose of the present open-labeled, randomized, prospective study was to compare the effects of cyclical etidronate combined with alfacalcidol with those of cyclical etidronate alone on lumbar bone mineral density (BMD), bone resorption, and back pain in postmenopausal women with osteoporosis. Forty postmenopausal women with osteoporosis, 60-86 years of age, without any vertebral fractures in the lumbar spine, were randomly divided into two groups with 20 patients in each group. One group was treated with cyclical etidronate (oral etidronate 200 mg daily for 2 weeks every 3 months) and the other was given cyclical etidronate combined with alfacalcidol (cyclical etidronate plus alfacalcidol 1 Ig daily continuously). The BMD of the lumbar spine (L1-L4) measured by dual-energy X-ray absorptiometry, urinary crosslinked N-terminal telopeptides of type I collagen (NTX) measured by an enzyme-linked immunosorbent assay, and back pain evaluated by the face scale score were assessed at baseline, 6 months, and 12 months. There were no significant differences in baseline characteristics including age, body mass index, years since menopause, lumbar BMD, urinary NTX level, and face scale score between the two treatment groups. Both treatments significantly reduced the urinary NTX level and back pain. Cyclical etidronate combined with alfacalcidol significantly increased the lumbar BMD with a more significant reduction in the urinary NTX level than cyclical etidronate alone, but cyclical etidronate alone did not significantly increase the lumbar BMD. Alleviation of back pain was similar in the two groups. These results suggest that cyclical etidronate combined with alfacalcidol appears to be more useful than cyclical etidronate alone for increasing the lumbar BMD by more markedly suppressing bone resorption in postmenopausal women with osteoporosis.

  10. Cyclic Creep of Ultrafine-Grained Pure Cu Under Cyclic Tension Deformation

    NASA Astrophysics Data System (ADS)

    Wu, Yanjun; Yang, Jingwen; Shen, Xu; Zhu, Rong

    2017-02-01

    The uniaxial ratcheting behavior of ultrafine-grained pure Cu processed by equal-channel angular pressing (ECAP) was investigated through uniaxial asymmetric cyclic stress-controlled experiments at room temperature. The effects of the mean stress and stress amplitude on the uniaxial ratcheting response and ratcheting life of the ECAP Cu were analyzed. With increasing mean stress or stress amplitude, the ratcheting strain and its rate increased, but the ratcheting life decreased. An approach based on Basquin's method was used to describe the fatigue lifetime of the ECAP pure Cu. Additionally, a power law relationship was adopted to describe the cyclic steady creep rate. Finally, the microscopic and macroscopic fracture features were examined. It was found that at high peak stresses, cyclic creep governs the overall failure process; otherwise, cyclic creep-fatigue interaction is the dominant failure mode.

  11. Involvement of cyclic nucleotide-dependent protein kinases in cyclic AMP-mediated vasorelaxation

    PubMed Central

    Eckly-Michel, Anita; Martin, Viviane; Lugnier, Claire

    1997-01-01

    The involvement of cyclic AMP-dependent protein kinase (PKA) and cyclic GMP-dependent protein kinase (PKG) in the effects of cyclic AMP-elevating agents on vascular smooth muscle relaxation, cyclic nucleotide dependent-protein kinase activities and ATP-induced calcium signalling ([Ca2+]i) was studied in rat aorta. Cyclic AMP-elevating agents used were a β-adrenoceptor agonist (isoprenaline), a phosphodiesterase 3 (PDE3) inhibitor (SK&F 94120) and a PDE4 inhibitor (rolipram). In rat intact aorta, the relaxant effect induced by isoprenaline (0.01–0.3 μM) was decreased by a specific inhibitor of PKA, H-89, whereas a specific inhibitor of PKG, Rp-8-Br-cyclic GMPS, was without effect. No significant difference in PKA and PKG activity ratios was detected in aortic rings when isoprenaline 10 μM was used. At the same concentration, isoprenaline did not modify ATP-induced changes in [Ca2+]i in smooth muscle cells. Neither H-89 nor Rp-8-Br-cyclic GMPS modified this response. These findings suggest that PKA is only involved in the relaxant effect induced by low concentrations of isoprenaline (0.01–0.3 μM), whereas for higher concentrations, other mechanisms independent of PKA and PKG are involved. The relaxant effects induced by SK&F 94120 and rolipram were inhibited by Rp-8-Br-cyclic GMPS with no significant effect of H-89. Neither SK&F 94120, nor rolipram at 30 μM significantly modified the activity ratios of PKA and PKG. Rolipram inhibited the ATP-induced transient increase in [Ca2+]i. This decrease was abolished by Rp-8-Br-cyclic GMPS whereas H-89 had no significant effect. These results suggest that PKG is involved in the vascular effects induced by the inhibitors of PDE3 and PDE4. Moreover, since it was previously shown that PDE3 and PDE4 inhibitors only increased cyclic AMP levels with no change in cyclic GMP level, these data also suggest a cross-activation of PKG by cyclic AMP in rat aorta. The combination of 5 μM SK&F 94120 with rolipram markedly

  12. Cyclic hardening in copper described in terms of combined monotonic and cyclic stress-strain curves

    SciTech Connect

    Chandler, H.D. . School of Mechanical Engineering)

    1995-01-01

    Hardening of polycrystalline copper subjected to tension-compression loading cycles in the plastic region is discussed with reference to changes in flow stress determined from equations describing dislocation glide. It is suggested that hardening is as a result of the accumulation of strain on a monotonic stress-strain curve. On initial loading, the behavior is monotonic. On stress reversal, a characteristic cyclic stress-strain curve is followed until the stress reaches a value in reverse loading corresponding to the maximum attained during the preceding half cycle. Thereafter, the monotonic path is followed until strain reversal occurs at completion of the half cycle. Repetition of the process results in cyclic hardening. Steady state cyclic behavior is reached when a stress associated with the monotonic stress-strain curve is reached which is equal to the stress associated with the cyclic stress-strain curve corresponding to the imposed strain amplitude.

  13. Use the Nutrition Facts Label

    MedlinePlus

    ... Features Spokespeople News Archive eNewsletters Calendar Use the Nutrition Facts Label You can help your family eat ... to some of their favorite foods. Use the Nutrition Facts label found on food packages to make ...

  14. Decode the Sodium Label Lingo

    MedlinePlus

    ... For Preschooler For Gradeschooler For Teen Decode the Sodium Label Lingo Published January 24, 2013 Print Email Reading food labels can help you slash sodium. Here's how to decipher them. "Sodium free" or " ...

  15. Labeling lake water with tritium

    USGS Publications Warehouse

    Frederick, B.J.

    1963-01-01

    A method of packaging tritiated water in a manner that facilitates safe handling in environmental labeling operations, and procedures followed in labeling a large body of water with a small volume of tritiated water are described. ?? 1963.

  16. New Correlations Between Monotonic and Cyclic Properties of Metallic Materials

    NASA Astrophysics Data System (ADS)

    Zonfrillo, Giovanni

    2017-03-01

    Knowledge of the cyclic properties of metallic materials is often critical to correctly design structural components. However, cyclic data are not easily available in the literature, while tensile test data are easier to find in specialized sites or vendor catalogs. In this study, the cyclic strength coefficient and the cyclic strain hardening exponent of the Ramberg-Osgood law were evaluated using exclusively data obtained through monotonic tensile tests. The analyses were carried out on a large set of materials. The database used is composed of 338 alloys, mainly iron alloys, but also titanium and aluminum alloys. New subdivisions of the materials were introduced. Several original relations were suggested to correlate static and cyclic strength parameters. The evaluated values of both cyclic strength coefficient and cyclic strain hardening exponent were compared with experimental values coming from cyclic test, obtaining a satisfactory agreement and a higher accuracy if compared with similar relations found in the literature.

  17. Rhodium-Catalyzed Dehydrogenative Borylation of Cyclic Alkenes

    PubMed Central

    Kondoh, Azusa; Jamison, Timothy F.

    2010-01-01

    A rhodium-catalyzed dehydrogenative borylation of cyclic alkenes is described. This reaction provides direct access to cyclic 1-alkenylboronic acid pinacol esters, useful intermediates in organic synthesis. Suzuki-Miyaura cross-coupling applications are also presented. PMID:20107646

  18. FPT Algorithm for Two-Dimensional Cyclic Convolutions

    NASA Technical Reports Server (NTRS)

    Truong, Trieu-Kie; Shao, Howard M.; Pei, D. Y.; Reed, Irving S.

    1987-01-01

    Fast-polynomial-transform (FPT) algorithm computes two-dimensional cyclic convolution of two-dimensional arrays of complex numbers. New algorithm uses cyclic polynomial convolutions of same length. Algorithm regular, modular, and expandable.

  19. Collective Multi-Label Classification

    DTIC Science & Technology

    2005-01-01

    there is one output random variable . We begin by de- scribing this traditional classifier, then we describe its common ex- tension to the multi- label ...dependencies among the output variables . In addition to having feature for each label -term pair, CML main- tains features accounting for label co...over all possible multi- labelings — that is, over all subsets of Y . This method is intuitively appealing: it is easy to explain, and it is informative

  20. Cyclic stress analysis of ceramic coated gas turbine seals

    NASA Technical Reports Server (NTRS)

    Padovan, Joe; Dougherty, Dan; Hendricks, Bob

    1985-01-01

    Through the use of the Finite Element Method, the cyclic thermomechanical response of ceramic coated gas turbine parts is considered. The analysis includes temperature dependent elastic-plastic-creep material properties and cyclic thermal loads. To demonstrate the cyclic thermomechanical response, a ceramic coated outer gas path seal is studied. The analysis will estimate the significant residual stress field created by the cyclic thermal loads.

  1. Cyclic Photophosphorylation in the Mykotrophic Orhid Neottia nidus-avis

    PubMed Central

    Menke, Wilhelm; Schmid, Georg H.

    1976-01-01

    The mykotrophic orchid Neottia nidus-avis (L.) Rich. is not able to evolve oxygen in the light. Plastid preparations from the lip (labellum) of the orchid perform a photosystem I-dependent photoreduction of methylviologen with the artificial electron donor couple 2,6-dichlorophenol indophenol ascorbate. Photosystem II reactions such as the ferricyanide Hill reaction or the photoreduction of 2,6-dichlorophenol indophenol with diphenylcarbazide as the electron donor are not functioning. The plastids exhibit phenazine methosulfate-mediated cyclic photophosphorylation. After infiltration with 32P-labeled phosphate the labellum forms 32P-ATP in the light. This rate of ATP formation is enhanced by additional infiltration of phenazine methosulfate prior to illumination. The brown color of the plant is caused by an absorption shift of carotenoids to longer wavelength. By comparison of absorption spectra with the fluorescence excitation spectra of plastid preparations and of the extracted pigments we show that no appreciable energy transfer from carotenoids to chlorophyll occurs. PMID:16659557

  2. Cyclic Photophosphorylation in the Mykotrophic Orhid Neottia nidus-avis.

    PubMed

    Menke, W; Schmid, G H

    1976-05-01

    The mykotrophic orchid Neottia nidus-avis (L.) Rich. is not able to evolve oxygen in the light. Plastid preparations from the lip (labellum) of the orchid perform a photosystem I-dependent photoreduction of methylviologen with the artificial electron donor couple 2,6-dichlorophenol indophenol ascorbate. Photosystem II reactions such as the ferricyanide Hill reaction or the photoreduction of 2,6-dichlorophenol indophenol with diphenylcarbazide as the electron donor are not functioning. The plastids exhibit phenazine methosulfate-mediated cyclic photophosphorylation. After infiltration with (32)P-labeled phosphate the labellum forms (32)P-ATP in the light. This rate of ATP formation is enhanced by additional infiltration of phenazine methosulfate prior to illumination. The brown color of the plant is caused by an absorption shift of carotenoids to longer wavelength. By comparison of absorption spectra with the fluorescence excitation spectra of plastid preparations and of the extracted pigments we show that no appreciable energy transfer from carotenoids to chlorophyll occurs.

  3. Microgravity Science Glovebox - Labels

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Labels are overlaid on a photo (0003837) of the Microgravity Science Glovebox (MSG). The MSG is being developed by the European Space Agency (ESA) and NASA are developing the MSG for use aboard the International Space Station (ISS). Scientists will use the MSG to carry out multidisciplinary studies in combustion science, fluid physics and materials science. The MSG is managed by NASA's Marshall Space Flight Center (MSFC). Photo Credit: NASA/MSFC

  4. Food Labels Tell the Story!

    MedlinePlus

    ... My World From the Label to the Table! Food Labels Tell the Story! What is in food? Food provides your body with all of the ... your food choices. Nutrition Facts—the Labels on Food Products Beginning in 1994, the US government began ...

  5. Site-specific labeling of RNA at internal ribose hydroxyl groups: terbium-assisted deoxyribozymes at work.

    PubMed

    Büttner, Lea; Javadi-Zarnaghi, Fatemeh; Höbartner, Claudia

    2014-06-04

    A general and efficient single-step method was established for site-specific post-transcriptional labeling of RNA. Using Tb(3+) as accelerating cofactor for deoxyribozymes, various labeled guanosines were site-specifically attached to 2'-OH groups of internal adenosines in in vitro transcribed RNA. The DNA-catalyzed 2',5'-phosphodiester bond formation proceeded efficiently with fluorescent, spin-labeled, biotinylated, or cross-linker-modified guanosine triphosphates. The sequence context of the labeling site was systematically analyzed by mutating the nucleotides flanking the targeted adenosine. Labeling of adenosines in a purine-rich environment showed the fastest reactions and highest yields. Overall, practically useful yields >70% were obtained for 13 out of 16 possible nucleotide (nt) combinations. Using this approach, we demonstrate preparative labeling under mild conditions for up to ~160-nt-long RNAs, including spliceosomal U6 small nuclear RNA and a cyclic-di-AMP binding riboswitch RNA.

  6. Synthesis of cyclic sulfones by ring-closing metathesis.

    PubMed

    Yao, Qingwei

    2002-02-07

    A general and highly efficient synthesis of cyclic sulfones based on ring-closing metathesis has been developed. The synthetic utility of the resulting cyclic sulfones was demonstrated by their participation in stereoselective Diels-Alder reactions and transformation to cyclic dienes by the Ramberg-Bäcklund reaction.

  7. Cyclic soft groups and their applications on groups.

    PubMed

    Aktaş, Hacı; Özlü, Serif

    2014-01-01

    In crisp environment the notions of order of group and cyclic group are well known due to many applications. In this paper, we introduce order of the soft groups, power of the soft sets, power of the soft groups, and cyclic soft group on a group. We also investigate the relationship between cyclic soft groups and classical groups.

  8. Pharmacological modulation of secondary mediator systems--cyclic AMP and cyclic GMP--on inflammatory hyperalgesia.

    PubMed

    Cunha, F Q; Teixeira, M M; Ferreira, S H

    1999-06-01

    1. The objective of the present paper was to evaluate the relevance of neuronal balance of cyclic AMP and cyclic GMP concentration for functional regulation of nociceptor sensitivity during inflammation. 2. Injection of PGE2 (10-100 ng paw-1) evoked a dose-dependent hyperalgesic effect which was mediated via a cyclic AMP-activated protein kinase (PKA) inasmuch as hyperalgesia was blocked by the PKA inhibitor H89. 3. The PDE4 inhibitor rolipram and RP73401, but not PDE3 and PDE5 inhibitors potentiated the hyperalgesic effects of PGE2. The hyperalgesic effect of dopamine was also enhanced by rolipram. Moreover, rolipram significantly potentiated hyperalgesia induced by carrageenan, bradykinin, TNF alpha, IL-1 beta, IL-6 and IL-8. This suggests that neuronal cyclic AMP mediates the prostanoid and sympathetic components of mechanical hyperalgesia. Moreover, in the neuron cyclic AMP is mainly metabolized by PDE4. 4. To examine the role of the NO/cyclic GMP pathway in modulating mechanical hyperalgesia, we tested the effects of the soluble guanylate cyclase inhibitor, ODQ. This substance counteracts the inhibitory effects of the NO donor, SNAP, on the hyperalgesia induced by PGE2. 5. The ODQ potentiated hyperalgesia induced by carrageenan, bradykinin, TNF alpha, IL-1 beta, IL-6 and IL-8. In contrast, ODQ had no significant effect on the hyperalgesia induced by PGE2 and dopamine. This indicates that the hyperalgesic cytokines may activate soluble guanylate cyclase, which down-regulate the ability of these substances to cause hyperalgesia. This event appears not to be mediated by prostaglandin or dopamine. 6. In conclusion, the results presented in this paper confirm an association between (i) hyperalgesia and elevated levels of cyclic AMP as well as (ii) antinociception and elevated levels of cyclic GMP. The intracellular levels of cyclic AMP that enhance hyperalgesia are controlled by the PDE4 isoform and appear to result in activation of protein kinase A whereas the

  9. Learning with imperfectly labeled patterns

    NASA Technical Reports Server (NTRS)

    Chittineni, C. B.

    1979-01-01

    The problem of learning in pattern recognition using imperfectly labeled patterns is considered. The performance of the Bayes and nearest neighbor classifiers with imperfect labels is discussed using a probabilistic model for the mislabeling of the training patterns. Schemes for training the classifier using both parametric and non parametric techniques are presented. Methods for the correction of imperfect labels were developed. To gain an understanding of the learning process, expressions are derived for success probability as a function of training time for a one dimensional increment error correction classifier with imperfect labels. Feature selection with imperfectly labeled patterns is described.

  10. Cyclic Polymers by Ring-Closure Strategies.

    PubMed

    Josse, Thomas; De Winter, Julien; Gerbaux, Pascal; Coulembier, Olivier

    2016-11-02

    The preparation of cyclic macromolecules has always represented a challenging task for polymer science, mainly because of difficulties in connecting chain extremities together. Initiated by the pioneering studies of Jacobson and Stockmayer, preparative pathways to cyclic polymers have been considerably improved within the last two decades thanks to the advent of both controlled polymerizations and efficient coupling reactions in organic chemistry. This Review aims to provide a critical up-to-date overview and illustrate the considerable efforts that have been made in the past few years to improve the availability of macrocycles for industrial and academic investigations through the use of the ring-closure approach. Particular attention is paid to methods for the preparation of monocycles over more complex architectures, since the latter are usually derived from the former. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Separation of isotopes by cyclical processes

    DOEpatents

    Hamrin, Jr., Charles E.; Weaver, Kenny

    1976-11-02

    Various isotopes of hydrogen are separated by a cyclic sorption process in which a gas stream containing the isotopes is periodically passed through a high pressure column containing a palladium sorbent. A portion of the product from the high pressure column is passed through a second column at lower pressure to act as a purge. Before the sorbent in the high pressure column becomes saturated, the sequence is reversed with the stream flowing through the former low-pressure column now at high pressure, and a portion of the product purging the former high pressure column now at low pressure. The sequence is continued in cyclic manner with the product being enriched in a particular isotope.

  12. Cyclic Oxidation Modeling and Life Prediction

    NASA Technical Reports Server (NTRS)

    Smialek, James L.

    2004-01-01

    The cyclic oxidation process can be described as an iterative scale growth and spallation sequence by a number of similar models. Model input variable include oxide scale type and growth parameters, spalling geometry, spall constant, and cycle duration. Outputs include net weight change, the amounts of retained and spalled oxide, the total oxygen and metal consumed, and the terminal rates of weight loss and metal consumption. All models and their variations produce a number of similar characteristic features. In general, spalling and material consumption increase to a steady state rate, at which point the retained scale approaches a constant and the rate of weight loss becomes linear. For one model, this regularity was demonstrated as dimensionless, universal expressions, obtained by normalizing the variables by critical performance factors. These insights were enabled through the use of the COSP for Windows cyclic oxidation spalling program.

  13. A cyclic UH model for sand

    NASA Astrophysics Data System (ADS)

    Zheng, Wan

    2015-06-01

    A simple cyclic elastoplastic constitutive model for sand is proposed based on the UH model for overconsolidated clay. The proposed model has the following features. First, in order to describe the stress-induced anisotropy in sand, a rotational hardening rule is introduced for the evolution of the yield surface axis with development of plastic deviatoric strain in the principal stress space. Second, the relationship between the rotational axis and stress-induced anisotropy is modeled by introducing the slope of rotational axis into the yield function. The flatness of the yield surface can be determined by the slope of rotational axis. Finally, a revised unified hardening parameter is proposed to incorporate the stress-induced anisotropy. The model capability in describing the cyclic response of sand is verified by comparing the simulations with available test results.

  14. Cyclic plasticity and failure of structural components

    NASA Technical Reports Server (NTRS)

    Kalev, I.

    1980-01-01

    An analytical approach for low-cycle fatigue prediction is presented. The approach combines a cyclic plasticity model with the finite element method and a damage accumulation criterion for ductile metals. The cyclic plasticity model is based on the concept of the combination of several yield surfaces. The surfaces are related to the material uniaxial stress-strain curve idealized by piecewise linear segments. The damage criterion is based on the Coffin-Manson formulae modified for the mean stress variation effect. It is extended to the multiaxial varying stress-strain field and applied for both the crack initiation and the crack growth processes. The stable slow crack growth rate is approximated by the damage accumulation gradient computed from the cracked finite element models. This procedure requires fatigue testing data of only smooth specimens under constant strain amplitudes. The present approach is illustrated by numerical examples of an aircraft wing stiffened panel subjected to compression, which causes material yielding and residual tension.

  15. Cyclic Cushing syndrome: definitions and treatment implications.

    PubMed

    Velez, Dennis A; Mayberg, Marc R; Ludlam, William H

    2007-01-01

    Endogenous Cushing syndrome (CS) results from hypercortisolemia caused by excess adrenocorticotropic hormone production in a pituitary adenoma or ectopic tumor, or by an adrenal tumor that directly produces excess cortisol. The diagnosis can usually be ascertained with a reasonable degree of certainty based on clinical and laboratory findings of hypercortisolism. There are patients, however, in whom the production of excess cortisol exhibits a cyclic or intermittent pattern, and, as a result, the clinical symptoms may be quite complex and varied. In these patients the hypothalamic-pituitary-adrenal axis may be normal between cycles, and dexamethasone suppression testing may produce a paradoxical response. In the present article, the authors provide a definition of cyclic Cushing syndrome, review the causes and its potential pathophysiological mechanisms, and discuss the treatment options based on a review of the available literature.

  16. Review of nutrition labeling formats.

    PubMed

    Geiger, C J; Wyse, B W; Parent, C R; Hansen, R G

    1991-07-01

    This article examines nutrition labeling history as well as the findings of nine research studies of nutrition labeling formats. Nutrition labeling regulations were announced in 1973 and have been periodically amended since then. In response to requests from consumers and health care professionals for revision of the labeling system, the Food and Drug Administration initiated a three-phase plan for reform of nutrition labeling in 1990. President Bush signed the Nutrition Labeling and Education Act in November 1990. Literature analysis revealed that only nine studies with an experimental design have focused on nutrition labeling since 1971. Four were conducted before 1975, which was the year that nutrition labeling was officially implemented, two were conducted in 1980, and three were conducted after 1986. Only two of the nine studies supported the traditional label format mandated by the Code of Federal Regulations, and one study partially supported it. Four of the nine studies that evaluated graphic presentations of nutrition information found that consumer comprehension of nutrition information was improved with a graphic format for nutrition labeling: three studies supported the use of bar graphs and one study supported the use of a pie chart. Full disclosure (ie, complete nutrient and ingredient labeling) was preferred by consumers in two of the three studies that examined this variable. The third study supported three types of information disclosure dependent upon socioeconomic class. In those studies that tested graphics, a bar graph format was significantly preferred and showed better consumer comprehension than the traditional format.

  17. Map labeling and its generalizations

    SciTech Connect

    Doddi, S. |; Marathe, M.V.; Mirzaian, A.; Moret, B.M.E.; Zhu, B. |

    1997-01-01

    Map labeling is of fundamental importance in cartography and geographical information systems and is one of the areas targeted for research by the ACM Computational Geometry Impact Task Force. Previous work on map labeling has focused on the problem of placing maximal uniform, axis-aligned, disjoint rectangles on the plane so that each point feature to be labeled lies at the corner of one rectangle. Here, we consider a number of variants of the map labeling problem. We obtain three general types of results. First, we devise constant-factor polynomial-time-approximation algorithms for labeling point features by rectangular labels, where the feature may lie anywhere on the boundary of its label region and where labeling rectangles may be placed in any orientation. These results generalize to the case of elliptical labels. Secondly, we consider the problem of labeling a map consisting of disjoint rectilinear fine segments. We obtain constant-factor polynomial-time approximation algorithms for the general problem and an optimal algorithm for the special case where all segments are horizontal. Finally, we formulate a bicriteria version of the map-labeling problem and provide bicriteria polynomial- time approximation schemes for a number of such problems.

  18. Asymmetric Redox-Annulation of Cyclic Amines

    PubMed Central

    2015-01-01

    Cyclic amines such as 1,2,3,4-tetrahydroisoquinoline undergo regiodivergent annulation reactions with 4-nitrobutyraldehydes. These redox-neutral transformations enable the asymmetric synthesis of highly substituted polycyclic ring systems in just two steps from commercial materials. The utility of this process is illustrated in a rapid synthesis of (−)-protoemetinol. Computational studies provide mechanistic insights and implicate the elimination of acetic acid from an ammonium nitronate intermediate as the rate-determining step. PMID:26348653

  19. Bound Cyclic Systems with the Envelope Theory

    NASA Astrophysics Data System (ADS)

    Semay, Claude; Buisseret, Fabien

    2017-09-01

    Approximate but reliable solutions of a quantum system with N identical particles can be easily computed with the envelope theory, also known as the auxiliary field method. This technique has been developed for Hamiltonians with arbitrary kinematics and one- or two-body potentials. It is adapted here for cyclic systems with N identical particles, that is to say systems in which a particle i has only an interaction with particles i-1 and i+1 (with N+1≡1).

  20. Antitumoral cyclic peptide analogues of chlamydocin.

    PubMed

    Bernardi, E; Fauchere, J L; Atassi, G; Viallefont, P; Lazaro, R

    1993-01-01

    A series of cyclic tetrapeptides bearing the bioactive alkylating group on an epsilon-amino-lysyl function have been examined for their antitumoral activity on L1210 and P388 murine leukemia cell lines. One analogue belonging to the chlamydocin family and bearing a beta-chloroethylnitrosourea group was found to be potent at inhibiting L1210 cell proliferation and had a higher therapeutic index than the reference compound bis-beta-chloroethylnitrosourea (BCNU) on the in vivo P388-induced leukemia model.

  1. Cyclic change in late triassic lacustrine communities.

    PubMed

    Olsen, P E; Remington, C L; Cornet, B; Thomson, K S

    1978-08-25

    A new type of lake and shore assemblage has been found in the Late Triassic age rocks of North Carolina and Virginia (Dan River group). It includes abundant aquatic reptiles, fishes, at least seven orders of insects, crustaceans, and a diverse flora. Cyclic changes in the fauna and flora correlate with sedimentary cycles, which together reflect the repetitive development and extinction of large meromictic lakes.

  2. Cyclic spectrum based carrier recovery for OQPSK

    NASA Astrophysics Data System (ADS)

    Peng, Hua; Li, Jing

    2011-10-01

    A union carrier synchronization scheme of feed-forward frequency offset estimation and PLL for OQPSK signals is discussed in this paper. A feed-forward frequency offset estimator is developed based on the cyclic spectrum of the received signal. In order to suppress channel noise, an improved strategy is proposed. Simulations show that the presented scheme can achieve steady state much more quickly than conventional Costas loop. At the same time, the steady error of the union scheme is also smaller.

  3. Stereochemistry of Reaction Involving Cyclic Peroxides.

    DTIC Science & Technology

    1981-09-25

    peroxides are formed. For example, squalene absorbs two moles of oxygen upon autoxidation and one of these oxygen molecules is incorporated as a...peroxide, rather than a hydroperoxide group. Although no rigorous structure proof was offered for the squalene oxidation product, it seem likely on the basis...of subsequent work that the principal product of squalene autoxidation is one of the cyclic peroxides (1 or 2) formed by the mechanism described

  4. Recurrence of cyclic esotropia after surgical correction.

    PubMed

    Cahill, M; Walsh, J; McAleer, A

    1999-12-01

    Cyclic esotropia is a rare form of strabismus in which a convergent squint appears and disappears typically, but not always, in a regular 48-hour cycle. Characteristically, the convergent squint, when present, has a large angle with associated suppression and no binocular function. On normal or "nonsquinting" days, no manifest deviation is detectable (although in some cases there may be an esophoria). Physiologic diplopia is appreciated, whereas fusion and stereopsis are all normal. Amblyopia may occur in up to 20% of cases.

  5. Accumulation of inositol phosphates and cyclic AMP in guinea-pig cerebral cortical preparations. Effects of norepinephrine, histamine, carbamylcholine and 2-chloroadenosine.

    PubMed

    Hollingsworth, E B; Daly, J W

    1985-11-20

    Norepinephrine and serotonin augment by about 2-fold the accumulation of cyclic [3H]AMP elicited by 2-chloroadenosine in [3H]adenine-labeled guinea-pig cerebral cortical slices. Histamine causes a 3-fold augmentation. The first two agents have no effect on cyclic AMP alone, while histamine has only a small effect alone. The augmentation of the 2-chloroadenosine response appears to be mediated by alpha 1-adrenergic, 5HT2-serotonergic and H2-histaminergic receptors. VIP-elicited accumulations of cyclic AMP are also augmented through stimulation of alpha 1-adrenergic, 5HT2-serotonergic and H1-histaminergic receptors. Activation of these amine receptors also increases the turnover of phosphatidylinositols in [3H]inositol-labeled guinea pig cerebral cortical slices. Norepinephrine causes a 5-fold, serotonin a 1.2-fold, and histamine a 2.5-fold increase in accumulations of [3H]inositol phosphates. 2-Chloroadenosine, vasoactive intestinal peptide, baclofen, and somatostatin have no effect on phosphatidylinositol turnover, nor do the last two agents augment accumulations of cyclic AMP elicited by 2-chloroadenosine. The data suggest a possible relationship between turnover of phosphatidylinositol and the augmentations of the cyclic AMP accumulations elicited by biogenic amines in brain slices.

  6. Cyclic biamperometry at micro-interdigitated electrodes.

    PubMed

    Rahimi, Mehdi; Mikkelsen, Susan R

    2011-10-01

    Cyclic biamperometry was studied as an analytical method for use with commercially available, comb-type, coplanar microinterdigitated electrodes (μIDEs), using the ferri-/ferrocyanide redox couple as a model analyte. The μIDEs studied in this work were made of gold that had been deposited onto a Ti/W adhesion layer on borosilicate glass chips and had 5 and 10 μm bands with equal gap sizes. Close proximity of the two working electrodes, and their interdigitation, resulted in signal amplification by redox cycling. Results were compared with those obtained by cyclic voltammetry, where one of the two IDE electrodes was used as the working electrode and external reference and auxiliary electrodes were used. Amplification factors of almost 20 were achieved due to redox cycling. Attempts to apply cyclic voltammetry to the μIDEs, with one of the combs as the working and the other as the auxiliary electrode, were unsuccessful due to corrosion of the auxiliary electrode comb. Results of this study, and the electrochemically unique feature of biamperometry to probe but not change the net contents of the medium under examination, suggest the applicability of scanning biamperometry at μIDEs to the very small volumes and electrochemical cell dimensions that are now of great interest.

  7. Scale factor duality for conformal cyclic cosmologies

    NASA Astrophysics Data System (ADS)

    Camara da Silva, U.; Alves Lima, A. L.; Sotkov, G. M.

    2016-11-01

    The scale factor duality is a symmetry of dilaton gravity which is known to lead to pre-big-bang cosmologies. A conformal time version of the scale factor duality (SFD) was recently implemented as a UV/IR symmetry between decelerated and accelerated phases of the post-big-bang evolution within Einstein gravity coupled to a scalar field. The problem investigated in the present paper concerns the employment of the conformal time SFD methods to the construction of pre-big-bang and cyclic extensions of these models. We demonstrate that each big-bang model gives rise to two qualitatively different pre-big-bang evolutions: a contraction/expansion SFD model and Penrose's Conformal Cyclic Cosmology (CCC). A few examples of SFD symmetric cyclic universes involving certain gauged Kähler sigma models minimally coupled to Einstein gravity are studied. We also describe the specific SFD features of the thermodynamics and the conditions for validity of the generalized second law in the case of Gauss-Bonnet (GB) extension of these selected CCC models.

  8. Cyclic viscoelastoplasticity of polypropylene/nanoclay composites

    NASA Astrophysics Data System (ADS)

    Drozdov, A. D.; deC. Christiansen, J.

    2012-11-01

    Observations are reported on isotactic polypropylene/organically modified nanoclay hybrids with concentrations of filler ranging from 0 to 5 wt.% in cyclic tensile tests with a stress-controlled program (oscillations between various maximum stresses and the zero minimum stress). A pronounced effect of nanofiller is demonstrated: reinforcement with 2 wt.% of clay results in strong reduction of maximum and minimum strains per cycle and growth of number of cycles to failure compared with neat polypropylene. To rationalize these findings, a constitutive model is developed in cyclic viscoelasticity and viscoplasticity of polymer nanocomposites. Adjustable parameters in the stress-strain relations are found by fitting experimental data. The model correctly describes the growth of the ratcheting strain and shows that fatigue failure is driven by a pronounced increase in plastic strain in the crystalline phase. To assess the influence of loading conditions on the changes in the material parameters, experimental data on polypropylene are studied in cyclic tests with a strain-controlled program (oscillations between fixed maximum and minimum strains) and a mixed program (oscillations between various maximum strains and the zero minimum stress). Numerical simulation confirms the ability of the model to predict the evolution of stress-strain diagrams with the number of cycles.

  9. Cosmic perturbations through the cyclic ages

    SciTech Connect

    Erickson, Joel K.; Gratton, Steven; Steinhardt, Paul J.; Turok, Neil

    2007-06-15

    We analyze the evolution of cosmological perturbations in the cyclic model, paying particular attention to their behavior and interplay over multiple cycles. Our key results are: (1) galaxies and large scale structure present in one cycle are generated by the quantum fluctuations in the preceding cycle without interference from perturbations or structure generated in earlier cycles and without interfering with structure generated in later cycles; (2) the ekpyrotic phase, an epoch of gentle contraction with equation of state w>>1 preceding the hot big bang, makes the universe homogeneous, isotropic and flat within any given observer's horizon; and (3) although the universe is uniform within each observer's horizon, the structure of the cyclic universe on very large scales is more complex, owing to the effects of superhorizon length perturbations, and cannot be described globally as a Friedmann-Robertson-Walker cosmology. In particular, we show that the ekpyrotic contraction phase is so effective in smoothing, flattening and isotropizing the universe within the horizon that this phase alone suffices to solve the horizon and flatness problems even without an extended period of dark energy domination (a kind of low energy inflation). Instead, the cyclic model rests on a genuinely novel, noninflationary mechanism (ekpyrotic contraction) for resolving the classic cosmological conundrums.

  10. Cyclic dominance in evolutionary games: a review

    PubMed Central

    Szolnoki, Attila; Mobilia, Mauro; Jiang, Luo-Luo; Szczesny, Bartosz; Rucklidge, Alastair M.; Perc, Matjaž

    2014-01-01

    Rock is wrapped by paper, paper is cut by scissors and scissors are crushed by rock. This simple game is popular among children and adults to decide on trivial disputes that have no obvious winner, but cyclic dominance is also at the heart of predator–prey interactions, the mating strategy of side-blotched lizards, the overgrowth of marine sessile organisms and competition in microbial populations. Cyclical interactions also emerge spontaneously in evolutionary games entailing volunteering, reward, punishment, and in fact are common when the competing strategies are three or more, regardless of the particularities of the game. Here, we review recent advances on the rock–paper–scissors (RPS) and related evolutionary games, focusing, in particular, on pattern formation, the impact of mobility and the spontaneous emergence of cyclic dominance. We also review mean-field and zero-dimensional RPS models and the application of the complex Ginzburg–Landau equation, and we highlight the importance and usefulness of statistical physics for the successful study of large-scale ecological systems. Directions for future research, related, for example, to dynamical effects of coevolutionary rules and invasion reversals owing to multi-point interactions, are also outlined. PMID:25232048

  11. Tumors exposed to acute cyclic hypoxia show increased vessel density and delayed blood supply.

    PubMed

    Gaustad, Jon-Vidar; Simonsen, Trude Golimo; Roa, Ana Maria Acosta; Rofstad, Einar K

    2013-01-01

    The purpose of this study was to investigate the effect of acute cyclic hypoxia on tumor vasculature. A-07 human melanoma xenografts growing in dorsal window chambers were used as tumor model. Acute cyclic hypoxia was induced by periodically exposing tumor-bearing mice to a low oxygen atmosphere. The hypoxia treatment consisted of 12 cycles of 10 min of low O(2) (8% O(2) in N(2)) followed by 10 min of air for a total of 4 hr. The treatment started the first day after tumor initiation, and was given daily for 9 days. Vascular morphology was assessed from high-resolution transillumination images, and tumor blood supply was assessed from first-pass imaging movies recorded after a bolus of 155 kDa tetramethylrhodamine isothiocyanate-labeled dextran had been administered intravenously. Hypoxia-treated tumors showed increased vessel density, decreased interstitial distance, and delayed blood supply compared to control tumors. The increase in vessel density was attributed to an increased number of small vessels. In conclusion, acute cyclic hypoxia induced angiogenesis in A-07 tumors resulting in increased density of small-diameter vessels and delayed tumor blood supply. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Externally applied cyclic strain regulates localization of focal contact components in cultured smooth muscle cells.

    PubMed

    Cunningham, James J; Linderman, Jennifer J; Mooney, David J

    2002-01-01

    Mechanical signals are critical regulators of cellular gene expression, yet little is understood of the mechanism whereby cells sense mechanical forces. In this study we have tested the hypothesis that mechanical strain applied to populations of cells via their adhesion substrate rapidly alters the cellular distribution of focal contact proteins. Focal contact-associated components (vinculin, a-actinin, paxillin) were assayed by immunofluorescence microscopy and quantitative western blotting. Application of a single step increase in strain in multiple experiments caused overall a small change in focal contact-associated vinculin. In contrast, cyclic strain induced a large and very reproducible increase in detergent-insoluble vinculin (52% relative to static) after just 1 min of strain. Insoluble paxillin was transiently enriched with a similar time course, whereas insoluble a-actinin did not change significantly in response to cyclic strain. Rhodamine-labeled chicken vinculin added to permeabilized cells preferentially localized to focal contacts in response to cyclic strain, but not a single step increase in strain. These findings establish that insoluble levels of focal contact components are altered rapidly following application of an appropriate number of mechanical perturbations, and suggest that at least one component of the mechanism does not involve soluble intermediates.

  13. Effect on platelet functions of derivatives of cyclic nucleotides.

    PubMed

    Pareti, F I; Carrera, D; Mannucci, L; Mannucci, P M

    1978-04-30

    Derivatives of cyclic nucleotides were evaluated for their ability to inhibit platelet aggregation and the release reaction. Derivatives substituted in position 8 (mainly 8-Br-cyclic GMP) were more active than 3'-5' cyclic AMP, and their relative potency in inhibiting platelet aggregation and 14C-serotonin release was comparable to that of N62-0'-dibutyryl-cyclic AMP. Compounds substituted in position 6 or 2'-0 were not effective. The active compounds, which were also tested for their ability to stimulate platelet adenylate cyclase or to inhibit cyclic AMP phosphodiesterase, did not modify the intracellular levels of cyclic AMP. Since previous animal experiments have shown that these derivatives cause less side effects than cyclic AMP and its dibutyryl derivative in animals, it is suggested that modification of the cyclophosphate molecule might make it possible to find compounds active only on platelet function without interfering with other biological systems.

  14. Supplementing national menu labeling.

    PubMed

    Hodge, James G; White, Lexi C

    2012-12-01

    The US Food and Drug Administration's forthcoming national menu labeling regulations are designed to help curb the national obesity epidemic by requiring calorie counts on restaurants' menus. However, posted calories can be easily ignored or misunderstood by consumers and fail to accurately describe the healthiness of foods. We propose supplemental models that include nutritional information (e.g., fat, salt, sugar) or specific guidance (e.g., "heart-healthy" graphics). The goal is to empower restaurant patrons with better data to make healthier choices, and ultimately to reduce obesity prevalence.

  15. Synthesis, DTPA coupling and radio labeling of cationic aminodextran

    SciTech Connect

    Subramanian, G.; McAfee, J.G.; Schneider, R.F.; Zapf-Longo, C.; Palladino, E.; Lyons, B.J.; Roskopf, M.

    1984-01-01

    In glomerular diseases, the normal anionic charge of the basement membrane is lost at an early stage. Glomerular damage in rats has been detected more readily with cationic dextrans than with inulin. Hence, the authors attempted to demonstrate this phenomenon in vivo in rats with labeled cationic dextran. Aminated Dextran (AMDEX) was prepared by treating Dextran(mol. wt approx. = 15k) with sodium methoxide followed by a bromethylamine HBr in DMSO resulting in 10-25 aminogroups per mole. DTPA cyclic dianhydride was coupled to AMDEX using a weight ratio of 1:10 in 0.2 - 1.0 ml 0.42 M Hepes buffer at pH 7.4. Free DTPA was removed by gel filtration (Sephadex P6DG) or by using Centricon-10 (AMICON) centrifugal microconcentrators. AMDEX coupled with DTPA was labeled with Indium-111 in 0.25 M acetate buffer. Labeling yields were >90% by gel chromatography and electrophoresis (pH8.2 Barbitol buffer). AMEXDTPA was labeled also by ligand exchange with Tc-99m-Sn-citrate at neutral pH with a labeling yield of 30%. On electrophoresis, all the labeled samples retained their cationic character. The distribution of purified In-111 AMDEX, was compared with simultaneously IV injected Tc-99m DTPA in rats. The 2 hour urinary excretion, and renal clearance (calculated from the biexponential plasma clearance) were slower (70 to 80%) than those of DTPA, due to the larger molecular size of AMDEX. By 1 hr., 5% of the administered activity was retained in each kidney, probably due to adherence to anionic binding sites.

  16. 49 CFR 583.5 - Label requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of the fuel economy label required by 15 U.S.C. 2006, or a separate label. A separate label may... case of a label that is included as part of the Monroney price information label or fuel economy label... motor vehicle equipment and that, to the best of the requester's knowledge, the outside supplier is...

  17. Food labels: a critical assessment.

    PubMed

    Temple, Norman J; Fraser, Joy

    2014-03-01

    Foods sold in packages have both front-of-package (FOP) labels and back-of-package (BOP) labels. The aim of this review is to determine the role they play in informing consumers as to the composition of foods in order to help select a healthy diet. Recent literature was evaluated and findings combined with assessments made by the authors of food labels used in the United States and Canada. Research shows that most consumers have difficulty understanding the information provided by both FOP and BOP food labels used in the United States and Canada. Research has evaluated the merits of alternative designs. FOP labels should be based on a clear and simple design. They should present information on key nutrients (total fat, saturated fat, sugar, and sodium or salt) and also energy value. They should have color and words that indicate "high," "medium," and "low" levels. Labels can also state quantity per serving. The traffic light system is the best example of this design. An extra traffic light indicating the overall health value of the food should be added. A clearer BOP label also is needed. Implementation of a new food labeling system will probably be opposed by the food industry. More research is needed into which food label designs are most effective, especially for persuading consumers to select healthier food. Both FOP and BOP food labels used in the United States and Canada need to be redesigned using a traffic light system. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Cyclic AMP and the regeneration of retinal ganglion cell axons.

    PubMed

    Hellström, Mats; Harvey, Alan R

    2014-11-01

    In this paper we present a brief review of studies that have reported therapeutic benefits of elevated cAMP on plasticity and regeneration after injury to the central nervous system (CNS). We also provide new data on the cellular mechanisms by which elevation of cyclic adenosine monophosphate (cAMP) promotes cytokine driven regeneration of adult CNS axons, using the visual system as the experimental model. cAMP is a second messenger for many intracellular signalling pathways. Elevation of cAMP in the eye by intravitreal injection of the cell permeant analogue (8-(4-chlorophenylthio)-adenosine-3',5'-cyclic monophosphate; CPT-cAMP), when added to recombinant ciliary neurotrophic factor (rCNTF), significantly enhances rCNTF-induced regeneration of adult rat retinal ganglion cell (RGC) axons into peripheral nerve (PN) grafted onto transected optic nerve. This effect is mediated to some extent by protein kinase A (PKA) signalling, but CPT-cAMP also acts via PI3K/Akt signalling to reduce suppressor of cytokine signalling protein 3 (SOCS3) activity in RGCs. Another target for cAMP is the exchange protein activated by cAMP (Epac), which can also mediate cAMP-induced axonal growth. Here we describe some novel results and discuss to what extent the pro-regenerative effects of CPT-cAMP on adult RGCs are mediated via Epac as well as via PKA-dependent pathways. We used the established PN-optic nerve graft model and quantified the survival and regenerative growth of adult rat RGCs after intravitreal injection of rCNTF in combination with a selective activator of PKA and/or a specific activator of Epac. Viable RGCs were identified by βIII-tubulin immunohistochemistry and regenerating RGCs retrogradely labelled and quantified after an injection of fluorogold into the distal end of the PN grafts, 4 weeks post-transplantation. The specific agonists of either PKA or Epac were both effective in enhancing the effects of rCNTF on RGC axonal regeneration, but interestingly, injections

  19. Regulation of intracellular cyclic AMP in skeletal muscle cells involves the efflux of cyclic nucleotide to the extracellular compartment

    PubMed Central

    Godinho, Rosely Oliveira; Costa-Jr, Valter Luiz

    2003-01-01

    This report analyses the intracellular and extracellular accumulation of cyclic AMP in primary rat skeletal muscle cultures, after direct and receptor-dependent stimulation of adenylyl cyclase (AC). Isoprenaline, calcitonin gene-related peptide (CGRP) and forskolin induced a transient increase in the intracellular cyclic AMP that peaked 5 min after onset stimulation. Under stimulation with isoprenaline or CGRP, the intracellular cyclic AMP initial rise was followed by an exponential decline, reaching 46 and 52% of peak levels in 10 min, respectively. Conversely, the forskolin-dependent accumulation of intracellular cyclic AMP decreased slowly and linearly, reaching 49% of the peak level in 30 min. The loss of intracellular cyclic AMP from peak levels, induced by direct or receptor-induced activation of AC, was followed by an increase in the extracellular cyclic AMP. This effect was independent on PDEs, since it was obtained in the presence of 3-isobutyl-1-methylxanthine (IBMX). Besides, in isoprenaline treated cells, the beta-adrenoceptor antagonist propranolol reduced both intra- and extracellular accumulation of cyclic AMP, whereas the organic anion transporter inhibitor probenecid reduced exclusively the extracellular accumulation. Together our data show that direct or receptor-dependent activation of skeletal muscle AC results in a transient increase in the intracellular cyclic AMP, despite the continuous presence of the stimulus. The temporal declining of intracellular cyclic AMP was not dependent on the cyclic AMP breakdown but associated to the efflux of cyclic nucleotide to the extracellular compartment, by an active transport since it was prevented by probenecid. PMID:12642402

  20. Aluminum alters cyclic AMP and cyclic GMP levels but not presynaptic cholinergic markers in rat brain in vivo.

    PubMed

    Johnson, G V; Jope, R S

    1987-02-10

    Oral administration of 0.3% aluminum (citrate or sulfate salt) for 4 weeks significantly elevated adenosine 3',5'-monophosphate (cyclic AMP) levels in rat cortex, hippocampus, striatum and cerebellum. The largest effect observed was a 60% increase in cortical cyclic AMP levels in rats administered aluminum sulfate. The effects of orally administered aluminum on guanosine 3',5'-monophosphate (cyclic GMP) levels were less widespread. Dietary aluminum citrate only elevated cyclic GMP levels in the hippocampus, while aluminum sulfate caused significant increases in the cerebellum, hippocampus and striatum. Aluminum citrate administered i.c.v. (1 mumol, 2 weeks postadministration) elevated cyclic AMP levels in the cortex, but had no effect on cyclic GMP levels. Aluminum administered either orally or i.c.v. had no effect on in vivo acetylcholine levels. However, dietary aluminum citrate significantly reduced choline levels in the cortex, hippocampus and striatum. Aluminum administered i.c.v. had no effect on choline acetyltransferase activity or on high-affinity choline transport. These results indicate that: the metabolism of cyclic AMP and of cyclic GMP are more sensitive to aluminum than are presynaptic cholinergic processes; the metabolism of cyclic AMP is more sensitive to the effects of aluminum than is the metabolism of cyclic GMP; and cortical cAMP metabolism is the most sensitive to the presence of aluminum. Possible consequences of elevated levels of cyclic nucleotides induced by aluminum in the brain are proposed.

  1. Statistical damage constitutive model for rocks subjected to cyclic stress and cyclic temperature

    NASA Astrophysics Data System (ADS)

    Zhou, Shu-Wei; Xia, Cai-Chu; Zhao, Hai-Bin; Mei, Song-Hua; Zhou, Yu

    2017-08-01

    A constitutive model of rocks subjected to cyclic stress-temperature was proposed. Based on statistical damage theory, the damage constitutive model with Weibull distribution was extended. Influence of model parameters on the stress-strain curve for rock reloading after stress-temperature cycling was then discussed. The proposed model was initially validated by rock tests for cyclic stress-temperature and only cyclic stress. Finally, the total damage evolution induced by stress-temperature cycling and reloading after cycling was explored and discussed. The proposed constitutive model is reasonable and applicable, describing well the stress-strain relationship during stress-temperature cycles and providing a good fit to the test results. Elastic modulus in the reference state and the damage induced by cycling affect the shape of reloading stress-strain curve. Total damage induced by cycling and reloading after cycling exhibits three stages: initial slow increase, mid-term accelerated increase, and final slow increase.

  2. Cyclic GMP and cyclic AMP changes in response to folic acid pulses during cell development of Dictyostelium discoideum.

    PubMed

    Wurster, B; Schubiger, K; Brachet, P

    1979-06-01

    Folic acid pulses induced developmental processes in agip 71, a morphogenetic mutant of Dictyostelium discoideum, strain Ax-2. Cells that had received folic acid pulses were able to form EDTA-stable cell aggregates and to complete full differentiation to fruiting bodies. In these cells no autonomous periodic activities were observed by light scattering. Folic acid pulses elicited increases in the concentrations of cyclic GMP and cyclic AMP. In undifferentiated cells, folic acid caused a rapid increase in the level of cyclic GMP without a significant change in the level of cyclic AMP. In an advanced developmental state folic acid caused an increase in cyclic AMP in addition to two successsive peaks of cyclic GMP. Experiments performed with the parent strain, Ax-2, also showed that during the development towards aggregation competence, cells acquired the ability to produce a cyclic AMP peak in response to folic acid.

  3. Virtual screening using combinatorial cyclic peptide libraries reveals protein interfaces readily targetable by cyclic peptides.

    PubMed

    Duffy, Fergal J; O'Donovan, Darragh; Devocelle, Marc; Moran, Niamh; O'Connell, David J; Shields, Denis C

    2015-03-23

    Protein-protein and protein-peptide interactions are responsible for the vast majority of biological functions in vivo, but targeting these interactions with small molecules has historically been difficult. What is required are efficient combined computational and experimental screening methods to choose among a number of potential protein interfaces worthy of targeting lead macrocyclic compounds for further investigation. To achieve this, we have generated combinatorial 3D virtual libraries of short disulfide-bonded peptides and compared them to pharmacophore models of important protein-protein and protein-peptide structures, including short linear motifs (SLiMs), protein-binding peptides, and turn structures at protein-protein interfaces, built from 3D models available in the Protein Data Bank. We prepared a total of 372 reference pharmacophores, which were matched against 108,659 multiconformer cyclic peptides. After normalization to exclude nonspecific cyclic peptides, the top hits notably are enriched for mimetics of turn structures, including a turn at the interaction surface of human α thrombin, and also feature several protein-binding peptides. The top cyclic peptide hits also cover the critical "hot spot" interaction sites predicted from the interaction crystal structure. We have validated our method by testing cyclic peptides predicted to inhibit thrombin, a key protein in the blood coagulation pathway of important therapeutic interest, identifying a cyclic peptide inhibitor with lead-like activity. We conclude that protein interfaces most readily targetable by cyclic peptides and related macrocyclic drugs may be identified computationally among a set of candidate interfaces, accelerating the choice of interfaces against which lead compounds may be screened.

  4. Optimizing connected component labeling algorithms

    SciTech Connect

    Wu, Kesheng; Otoo, Ekow; Shoshani, Arie

    2005-01-16

    This paper presents two new strategies that can be used to greatly improve the speed of connected component labeling algorithms. To assign a label to a new object, most connected component labeling algorithms use a scanning step that examines some of its neighbors. The first strategy exploits the dependencies among them to reduce the number of neighbors examined. When considering 8-connected components in a 2D image, this can reduce the number of neighbors examined from four to one in many cases. The second strategy uses an array to store the equivalence information among the labels. This replaces the pointer based rooted trees used to store the same equivalence information. It reduces the memory required and also produces consecutive final labels. Using an array instead of the pointer based rooted trees speeds up the connected component labeling algorithms by a factor of 5 {approx} 100 in our tests on random binary images.

  5. Optimizing connected component labeling algorithms

    NASA Astrophysics Data System (ADS)

    Wu, Kesheng; Otoo, Ekow; Shoshani, Arie

    2005-04-01

    This paper presents two new strategies that can be used to greatly improve the speed of connected component labeling algorithms. To assign a label to a new object, most connected component labeling algorithms use a scanning step that examines some of its neighbors. The first strategy exploits the dependencies among them to reduce the number of neighbors examined. When considering 8-connected components in a 2D image, this can reduce the number of neighbors examined from four to one in many cases. The second strategy uses an array to store the equivalence information among the labels. This replaces the pointer based rooted trees used to store the same equivalence information. It reduces the memory required and also produces consecutive final labels. Using an array instead of the pointer based rooted trees speeds up the connected component labeling algorithms by a factor of 5 ~ 100 in our tests on random binary images.

  6. Principles of protein labeling techniques.

    PubMed

    Obermaier, Christian; Griebel, Anja; Westermeier, Reiner

    2015-01-01

    Protein labeling methods prior to separation and analysis have become indispensable approaches for proteomic profiling. Basically, three different types of tags are employed: stable isotopes, mass tags, and fluorophores. While proteins labeled with stable isotopes and mass tags are measured and differentiated by mass spectrometry, fluorescent labels are detected with fluorescence imagers. The major purposes for protein labeling are monitoring of biological processes, reliable quantification of compounds and specific detection of protein modifications and isoforms in multiplexed samples, enhancement of detection sensitivity, and simplification of detection workflows. Proteins can be labeled during cell growth by incorporation of amino acids containing different isotopes, or in biological fluids, cells or tissue samples by attaching specific groups to the ε-amino group of lysine, the N-terminus, or the cysteine residues. The principles and the modifications of the different labeling approaches on the protein level are described; benefits and shortcomings of the methods are discussed.

  7. Cyclic AMP and cyclic GMP levels in glandular stomach of restrained rats.

    PubMed

    Zarrindast, M R; Sharghi, G; Gerayesh-Nejad, S; Djahanguiri, B

    1977-10-01

    Cyclic AMP and cyclic GMP were measured in glandular stomach of rats subjected to saline administration, cold (4 degrees C), restraint and restraint+cold after 15, 30, 60, 90 and 120 minutes. All animals subjected to restraint+cold had gastric ulceration after 2 hours. A significant but transient decrease in cAMP was observed 15 minutes after restraint+cold. A marked, sustained and significant decrease of cGMP was observed in the same group of animals. It is concluded that it seems unlikely to be a correlation between cAMP and cGMP changes of the stomach and the restraint-induced gastric ulceration.

  8. Label Structured Cell Proliferation Models

    DTIC Science & Technology

    2010-06-16

    variable as a mass-like quantity. The specific model for the dynamics of life and death processes of a population of cells labeled with CFSE is proposed in... variables = + where < 0 is label degradation velocity. Because we really don’t understand completely the degradation process (there appears to be...little agreement as to what variables on which this velocity might depend) and to allow for generality (other labels that might be used may well

  9. Label Ranking Algorithms: A Survey

    NASA Astrophysics Data System (ADS)

    Vembu, Shankar; Gärtner, Thomas

    Label ranking is a complex prediction task where the goal is to map instances to a total order over a finite set of predefined labels. An interesting aspect of this problem is that it subsumes several supervised learning problems, such as multiclass prediction, multilabel classification, and hierarchical classification. Unsurprisingly, there exists a plethora of label ranking algorithms in the literature due, in part, to this versatile nature of the problem. In this paper, we survey these algorithms.

  10. GEO label: The General Framework for Labeling and Certification

    NASA Astrophysics Data System (ADS)

    Bye, B. L.; McCallum, I.; Maso, J.

    2012-04-01

    The Group on Earth Observations (GEO) is coordinating efforts to build a Global Earth Observation System of Systems, or GEOSS. As part of a strategy to increase the involvement of the science and technology community in GEOSS, both as users and developers of GEOSS itself, GEO decided to develop a GEO label concept related to the scientific relevance, quality, acceptance and societal needs for services and data sets of GEOSS. The development of a GEO label is included in the GEO work plan and several projects address the challenges of developing a GEO label concept. Within the different projects developing the GEO label, various perspectives and approaches are being applied. In order to arrive at a generally accepted GEO label concept, a common understanding and basic knowledge of labeling is necessary. Assessment of quality of internationally standardized Earth observation data products implies possible certification. A general understanding of the framework for international standards and certification will also contribute to a more coherent discussion and more efficient development of a GEO label. We will describe the general labeling and certification framework emphasizing the relation to the three elements of the GEO label: quality, user acceptance and relevance. Based on a survey of international labels done by the EGIDA project, we have analyzed the legal framework and organization of labels and certification. We will discuss the frameworks for certification, user ratings, registration and analysis of user requirements. Quality assessment is a particular focus of the analysis and is based on the work done by the GeoViQua project. A GEO label will function both as a data distribution strategy and as a general management system for data. Through a label users can compare different data sets and get access to more information about the relevant data, including quality. A label will provide traceability of data both in the interest of users as well as data

  11. Labeling conventions in isoelectronic sequences

    SciTech Connect

    Maniak, S.T.; Curtis, L.J. )

    1990-08-01

    The isoelectronic exposition of atomic structure properties involves labeling ambiguities when more than one level of the same total angular momentum and parity is present, and an energy ordered labeling of these levels can lead to apparent isoelectronic discontinuities. For example, in the recent oscillator strength calculations for S-like ions by Saloman and Kim (Phys. Rev. A 38, 577 (1988)), abrupt changes in the rates were sometimes observed between one isoelectronic element and the next. We suggest an alternative labeling scheme that removes these discontinuities and produces a smooth isoelectronic variation. This alternative labeling offers advantages for data exposition and for semiempirical interpolation and extrapolation.

  12. Cyclic Nucleotide Signaling in Polycystic Kidney Disease

    PubMed Central

    Wang, Xiaofang; Ward, Christopher J.; Harris, Peter C.; Torres, Vicente E.

    2013-01-01

    Increased levels of 3’–5’-cyclic adenosine monophosphate (cAMP) stimulate cell proliferation and fluid secretion in polycystic kidney disease (PKD). Since hydrolytic capacity of phosphodiesterases (PDE) far exceeds maximum rate of synthesis by adenylyl cyclases (AC), cellular levels of cAMP are more sensitive to PDE inhibition than to AC activity changes. We have used enzymatic, western blot, immunohistochemistry, PCR and biochemical assays to study activity and expression of PDE families and isoforms and expression of downstream effectors of cAMP signaling in wildtype and PKD rat and mouse kidneys. The results indicate: 1) Species specific differences in PDE expression; higher PDE activity in kidneys from mice compared to rats; higher contribution of PDE1, relative to PDE4 and PDE3, to total PDE activity of kidney lysate and lower PDE1, PDE3 and PDE4 activities in murine cystic compared to wildtype kidneys. 2) Reduced levels of several PDE1, PDE3 and PDE4 proteins despite mRNA upregulation, possibly due to increased protein degradation. 3) Increased cGMP levels in polycystic kidneys, suggesting in vivo downregulation of PDE1 activity. 4) Additive stimulatory effect of cAMP and cGMP on cystogenesis in vitro. 5) Upregulation of cAMP-dependent protein kinase (PKA) subunits Iα and IIβ, PKare, CREB-1 mRNA, and CREM, ATF-1 and ICER proteins in cystic compared to wildtype kidneys. In summary, the results of this study suggest that alterations in cyclic nucleotide catabolism may render the cystic epithelium particularly susceptible to factors acting on Gs coupled receptors, account at least in part for the upregulation of cyclic nucleotide signaling in PKD, and contribute substantially to the progression of this disease. PMID:19924104

  13. Universal Behavior of a Cyclic Oxidation Model

    NASA Technical Reports Server (NTRS)

    Smialek, James L.

    2003-01-01

    A mathematical model has been generated to represent the iterative, discrete growth and spallation processes associated with cyclic oxidation. Parabolic growth kinetics (k(sub p)) over and a constant spall area (F(sub A)) were assumed, with spalling occurring interfacially at the thickest regions of the scale. Although most models require numerical techniques, the regularity and simplicity of this progression permitted an approximation by algebraic expressions. Normalization could now be performed to reflect all parametric effects, and a universal cyclic oxidation response was generated: W(sub u) = 1/2 {3J(sub u)(sup 1/2)+ J(sub u)(sup 3/2)} where W, is weight change normalized by the maximum and J(sub u) is the cycle number normalized by the number to reach maximum. Similarly, the total amount of metal consumed was represented by a single normalized curve. The factor [(S(sub c)-l)(raised dot)sqrt(F(sub A)k(sub p)DELTAt)] was identified as a general figure of merit, where S(sub c) is the mass ratio of oxide to oxygen and DELTAt is the cycle duration. A cyclic oxidation failure map was constructed, in normalized k(sub p)-F(sub A) space, as defined by the locus of points corresponding to a critical amount of metal consumption in a given time. All three constructions describe behavior for every value of growth rate, spall fraction, and cycle duration by means of single curves, but with two branches corresponding to the times before and after steady state is achieved.

  14. Modelling water molecules inside cyclic peptide nanotubes

    NASA Astrophysics Data System (ADS)

    Tiangtrong, Prangsai; Thamwattana, Ngamta; Baowan, Duangkamon

    2016-03-01

    Cyclic peptide nanotubes occur during the self-assembly process of cyclic peptides. Due to the ease of synthesis and ability to control the properties of outer surface and inner diameter by manipulating the functional side chains and the number of amino acids, cyclic peptide nanotubes have attracted much interest from many research areas. A potential application of peptide nanotubes is their use as artificial transmembrane channels for transporting ions, biomolecules and waters into cells. Here, we use the Lennard-Jones potential and a continuum approach to study the interaction of a water molecule in a cyclo[(- D-Ala- L-Ala)_4-] peptide nanotube. Assuming that each unit of a nanotube comprises an inner and an outer tube and that a water molecule is made up of a sphere of two hydrogen atoms uniformly distributed over its surface and a single oxygen atom at the centre, we determine analytically the interaction energy of the water molecule and the peptide nanotube. Using this energy, we find that, independent of the number of peptide units, the water molecule will be accepted inside the nanotube. Once inside the nanotube, we show that a water molecule prefers to be off-axis, closer to the surface of the inner nanotube. Furthermore, our study of two water molecules inside the peptide nanotube supports the finding that water molecules form an array of a 1-2-1-2 file inside peptide nanotubes. The theoretical study presented here can facilitate thorough understanding of the behaviour of water molecules inside peptide nanotubes for applications, such as artificial transmembrane channels.

  15. Cyclic groups and quantum logic gates

    NASA Astrophysics Data System (ADS)

    Pourkia, Arash; Batle, J.; Raymond Ooi, C. H.

    2016-10-01

    We present a formula for an infinite number of universal quantum logic gates, which are 4 by 4 unitary solutions to the Yang-Baxter (Y-B) equation. We obtain this family from a certain representation of the cyclic group of order n. We then show that this discrete family, parametrized by integers n, is in fact, a small sub-class of a larger continuous family, parametrized by real numbers θ, of universal quantum gates. We discuss the corresponding Yang-Baxterization and related symmetries in the concomitant Hamiltonian.

  16. A cyclic universe with colour fields

    NASA Astrophysics Data System (ADS)

    Yershov, Vladimir

    2009-03-01

    The topology of the universe is discussed in relation to the singularity problem. We explore the possibility that the initial state of the universe might have had a structure with 3-Klein bottle topology, which would lead to a model of a nonsingular oscillating (cyclic) universe with a well-defined boundary condition. The same topology is assumed to be intrinsic to the nature of the hypothetical primitive constituents of matter (usually called preons) giving rise to the observed variety of elementary particles. Some phenomenological implications of this approach are also discussed.

  17. Labeled Cocaine Analogs

    DOEpatents

    Goodman, Mark M.; Shi, Bing Zhi; Keil, Robert N.

    1999-03-30

    Novel methods for positron emission tomography or single photon emission spectroscopy using tracer compounds having the structure: ##STR1## where X in .beta. configuration is phenyl, naphthyl; 2,3 or 4-iodophenyl; 2,3 or 4-(trimethylsilyl)phenyl; 3,4,5 or 6-iodonaphthyl; 3,4,5 or 6-(trimethylsilyl)naphthyl; 2,3 or 4-(trialkylstannyl)phenyl; or 3,4,5 or 6-(trialkylstannyl)napthyl Y in .beta. configuration is 2-fluoroethoxy, 3-fluoropropoxy, 4-fluorobutoxy, 2-fluorocyclopropoxy, 2 or 3-fluorocyclobutoxy, R,S 1'-fluoroisopropoxy, R 1'-fluoroisopropoxy, S 1'-fluoroisopropoxy, 1',3'-difluoroisopropoxy, R,S 1'-fluoroisobutoxy, R 1'-fluoroisobutoxy, S 1'-fluoroisobutoxy, R,S 4'-fluoroisobutoxy, R 4'-fluoroisobutoxy, S 4'-fluoroisobutoxy, or 1',1'-di(fluoromethyl)isobutoxy, The compounds bind dopamine transporter protein and can be labeled with .sup.18 F or .sup.123 I for imaging.

  18. Laser labeling, a safe technology to label produce

    USDA-ARS?s Scientific Manuscript database

    Laser labeling of fruits and vegetables is an alternative means to label produce. Low energy CO2 laser beams etch the surface showing the contrasting underlying layer. These etched surfaces can promote water loss and potentially allow for entry of decay organisms. The long-term effects of laser labe...

  19. Laser labeling, a safe technology to label produce

    USDA-ARS?s Scientific Manuscript database

    Labeling of the produce has gained marked attention in recent years. Laser labeling technology involves the etching of required information on the surface using a low energy CO2 laser beam. The etching forms alphanumerical characters by pinhole dot matrix depressions. These openings can lead to wat...

  20. Intramolecular fluorine migration via four-member cyclic transition states

    PubMed

    Nguyen; Mayer; Morton

    2000-11-17

    Gaseous CF(3)(+) interchanges F(+) for O with simple carbonyl compounds. CF(3)(+) reacts with propionaldehyde in the gas phase to produce (CH(3))(2)CF(+) via two competing pathways. Starting with 1-(13)C-propionaldehyde, the major pathway (80%) produces (CH(3))(2)CF(+) with the carbon label in one of the methyl groups. The minor pathway (20%) produces (CH(3))(2)CF(+) with the carbon label in the central position. The relative proportions of these two pathways are measured by (19)F NMR analysis of the neutral CH(3)CF=CH(2) produced by deprotonation of (CH(3))(2)CF(+) at <10(-)(3) Torr in an electron bombardment flow (EBFlow) reactor. Formation of alkene in which carbon is directly bonded to fluorine means that (in the minor product, at least) an F(+) for O transposition occurs via adduct formation followed by 1,3-atom transfer and then isomerization of CH(3)CH(2)CHF(+) to the more stable (CH(3))(2)CF(+). Use of CF(4) as a chemical ionization (CI) reagent gas leads to CF(3)(+) adduct ions for a variety of ketones, in addition to isoelectronic transposition of F(+) for O. Metastable ion decompositions of the adduct ions yield the metathesis products. Decompositions of fluorocycloalkyl cations formed in this manner give evidence for the same kinds of rearrangements as take place in CH(3)CH(2)CHF(+). Density functional calculations confirm that F(+) for O metathesis takes place via addition of CF(3)(+) to the carbonyl oxygen followed by transposition via a four-member cyclic transition state. A computational survey of the effects of different substituents in a series of aldehydes and acyclic ketones reveals no systematic variation of the energy of the transition state as a function of thermochemistry, but the Hammond postulate does appear to be obeyed in terms of progress along the reaction coordinate. Bond lengths corresponding to the central barrier correlate with overall thermochemistry of the F(+) for O interchange, but in a sense opposite to what might have been

  1. Inter-rater reliability of cyclic and non-cyclic task assessment using the hand activity level in appliance manufacturing

    PubMed Central

    Paulsen, Robert; Schwatka, Natalie; Gober, Jennifer; Gilkey, David; Anton, Dan; Gerr, Fred; Rosecrance, John

    2015-01-01

    This study evaluated the inter-rater reliability of the American Conference of Governmental Industrial Hygienists (ACGIH®) hand activity level (HAL), an observational ergonomic assessment method used to estimate physical exposure to repetitive exertions during task performance. Video recordings of 858 cyclic and non-cyclic appliance manufacturing tasks were assessed by sixteen pairs of raters using the HAL visual-analog scale. A weighted Pearson Product Moment-Correlation Coefficient was used to evaluate the agreement between the HAL scores recorded by each rater pair, and the mean weighted correlation coefficients for cyclic and non-cyclic tasks were calculated. Results indicated that the HAL is a reliable exposure assessment method for cyclic (r̄-barw = 0.69) and non-cyclic work tasks (r̄-barw = 0.68). When the two reliability scores were compared using a two-sample Student's t-test, no significant difference in reliability (p = 0.63) between these work task categories was found. This study demonstrated that the HAL may be a useful measure of exposure to repetitive exertions during cyclic and non-cyclic tasks. Relevance to industry Exposure to hazardous levels of repetitive action during non-cyclic task completion has traditionally been difficult to assess using simple observational techniques. The present study suggests that ergonomists could use the HAL to reliably and easily evaluate exposures associated with some non-cyclic work tasks. PMID:26120222

  2. Repressible extracellular phosphodiesterases showing cyclic 2',3'- and cyclic 3',5'-nucleotide phosphodiesterase activities in Neurospora crassa.

    PubMed Central

    Hasunuma, K

    1983-01-01

    Two molecular species of repressible extracellular phosphodiesterases showing cyclic 2',3'- and cyclic 3',5'-nucleotide phosphodiesterase activities were detected in mycelial culture media of wild-type Neurospora crassa and purified. The two molecular species were found to be monomeric and polymeric forms of an enzyme constituted of identical subunits having molecular weights of 50,000. This enzyme had the same electrophoretic mobility as repressible acid phosphatase. The enzyme designated repressible cyclic phosphodiesterase showed pH optima of 3.2 to 4.0 with a cyclic 3',5'-AMP substrate and 5.0 to 5.6 with a cyclic 2',3'-AMP substrate. Repressible cyclic phosphodiesterase was activated by MnCl2 and CoCl2 with cyclic 2',3'-AMP as substrate and was slightly activated by MnCl2 with cyclic 3',5'-AMP. The enzyme hydrolyzed cyclic 3',5'- and cyclic 2',3'-nucleotides, in addition to bis-rho-nitrophenyl phosphate, but not certain 5' -and 3'-nucleotides. 3'-GMP and 3'-CMP were hydrolyzed less efficiently. Mutant strains A1 (nuc-1) and B1 (nuc-2), which cannot utilize RNA or DNA as a sole source of phosphorus, were unable to produce repressible cyclic phosphodiesterase. The wild type (74A) and a heterocaryon between strains A1 and B1 produced the enzyme and showed growth on orthophosphate-free media containing cyclic 2',3'-AMP or cyclic 3',5'-AMP, whereas both mutants showed little or no growth on these media. Images PMID:6311798

  3. Electrical Stimulation Decreases Coupling Efficiency Between Beta-Adrenergic Receptors and Cyclic AMP Production in Cultured Muscle Cells

    NASA Technical Reports Server (NTRS)

    Young, R. B.; Bridge, K. Y.

    1999-01-01

    Electrical stimulation of skeletal muscle cells in culture is an effective way to simulate the effects of muscle contraction and its effects on gene expression in muscle cells. Expression of the beta-adrenergic receptor and its coupling to cyclic AMP synthesis are important components of the signaling system that controls muscle atrophy and hypertrophy, and the goal of this project was to determine if electrical stimulation altered the beta-adrenergic response in muscle cells. Chicken skeletal muscle cells that had been grown for seven days in culture were subjected to electrical stimulation for an additional two days at a pulse frequency of 0.5 pulses/sec and a pulse duration of 200 msec. At the end of this two-day stimulation period, beta-adrenergic receptor population was measured by the binding of tritium-labeled CGP-12177 to muscle cells, and coupling to cAMP synthesis was measured by Radioimmunoassay (RIA) after treating the cells for 10 min with the potent (beta)AR agonist, isoproterenol. The number of beta adrenergic receptors and the basal levels of intracellular cyclic AMP were not affected by electrical stimulation. However, the ability of these cells to synthesize cyclic AMP was reduced by approximately 50%. Thus, an enhanced level of contraction reduces the coupling efficiency of beta-adrenergic receptors for cyclic AMP production.

  4. Electrical Stimulation Decreases Coupling Efficiency Between Beta-Adrenergic Receptors and Cyclic AMP Production in Cultured Muscle Cells

    NASA Technical Reports Server (NTRS)

    Young, R. B.; Bridge, K. Y.

    1999-01-01

    Electrical stimulation of skeletal muscle cells in culture is an effective way to simulate the effects of muscle contraction and its effects on gene expression in muscle cells. Expression of the beta-adrenergic receptor and its coupling to cyclic AMP synthesis are important components of the signaling system that controls muscle atrophy and hypertrophy, and the goal of this project was to determine if electrical stimulation altered the beta-adrenergic response in muscle cells. Chicken skeletal muscle cells that had been grown for seven days in culture were subjected to electrical stimulation for an additional two days at a pulse frequency of 0.5 pulses/sec and a pulse duration of 200 msec. At the end of this two-day stimulation period, beta-adrenergic receptor population was measured by the binding of tritium-labeled CGP-12177 to muscle cells, and coupling to cAMP synthesis was measured by Radioimmunoassay (RIA) after treating the cells for 10 min with the potent (beta)AR agonist, isoproterenol. The number of beta adrenergic receptors and the basal levels of intracellular cyclic AMP were not affected by electrical stimulation. However, the ability of these cells to synthesize cyclic AMP was reduced by approximately 50%. Thus, an enhanced level of contraction reduces the coupling efficiency of beta-adrenergic receptors for cyclic AMP production.

  5. Multiplex detection of microRNAs by combining molecular beacon probes with T7 exonuclease-assisted cyclic amplification reaction.

    PubMed

    Liu, Yacui; Zhang, Jiangyan; Tian, Jingxiao; Fan, Xiaofei; Geng, Hao; Cheng, Yongqiang

    2017-01-01

    A simple, highly sensitive, and specific assay was developed for the homogeneous and multiplex detection of microRNAs (miRNAs) by combining molecular beacon (MB) probes and T7 exonuclease-assisted cyclic amplification. An MB probe with five base pairs in the stem region without special modification can effectively prevent the digestion by T7 exonuclease. Only in the presence of target miRNA is the MB probe hybridized with the target miRNA, and then digested by T7 exonuclease in the 5' to 3' direction. At the same time, the target miRNA is released and subsequently initiates the nuclease-assisted cyclic digestion process, generating enhanced fluorescence signal significantly. The results show that the combination of T7 exonuclease-assisted cyclic amplification reaction and MB probe possesses higher sensitivity for miRNA detection. Moreover, multiplex detection of miRNAs was successfully achieved by designing two MB probes labeled with FAM and Cy3, respectively. As a result, the method opens a new pathway for the sensitive and multiplex detection of miRNAs as well as clinical diagnosis. Graphical Abstract A simple, highly sensitive, and specific assay was developed for the detection of microRNAs by combining molecular beacon probes with T7 exonuclease-assisted cyclic amplification reaction.

  6. Effects of cryosurgery on the healing pattern of rabbit mandibular bone. A triple fluorochrome labelling study.

    PubMed

    Kuylenstierna, R; Nathanson, A; Lundquist, P G

    1981-01-01

    The reparative process of rabbit mandibular bone injured by cryosurgery was studied by a triple fluorochromic method. The regeneration started late, when compared with fracture healing, and reached its maximum some 4-8 weeks after cryosurgery. A normal distribution of fluorochromes was registered after l2 weeks. The regeneration occurred mainly through growth from the marrow cavity region where the cryogenic impact may have stimulated osteogenesis from surviving endosteum and bone marrow. The destroyed periosteum at the site of the probe-tip attachment did not regenerate, although new bone formation of periosteal origin was noticed at the border of the injured cortex. The general distribution of fluorochromes seemed to follow closely the autoradiographic image obtained using 99TcmMDP in a similar experiment, suggesting comparable ways of accumulation in bone tissue.

  7. The role of peel stresses in cyclic debonding

    NASA Technical Reports Server (NTRS)

    Everett, R. A., Jr.

    1982-01-01

    When an adhesively bonded joint is undergoing cyclic loading, one of the possible damage modes that occurs is called cyclic debonding - progressive separation of the adherends by failure of the adhesive bond under cyclic loading. In most practical structures, both peel and shear stresses exist in the adhesive bonding during cyclic loading. The results of an experimental and analytical study to determine the role of peel stresses on cyclic debonding in a mixed mode specimen are presented. Experimentally, this was done by controlling the forces that create the peel stresses by applying a clamping force to oppose the peel stresses. Cracked lap shear joints were chosen for this study. A finite element analysis was developed to assess the effect of the clamping force on the strain energy release rates due to shear and peel stresses. The results imply that the peel stress is the principal stress causing cyclic debonding.

  8. Investigation of Cyclic Deformation and Fatigue of Polycrystalline Cu under Pure Compression Cyclic Loading Conditions

    NASA Astrophysics Data System (ADS)

    Hsu, Tzu-Yin Jean

    It is commonly accepted that fatigue crack is initiated under tensile fatigue stresses. However, practical examples demonstrate that cracks may also initiate under pure compressive fluctuating loads such as the failures observed in aircraft landing gear frames. However, the mechanism of such failures is rarely investigated. Furthermore, knowledge on cyclic deformation response under pure compressive fatigue condition is also very limited or non-existent. Our recent work already verified that fatigue cracks may nucleate from stress concentration sites under pure compression fatigue, but whether or not a form of stress concentration is always needed to initiate a crack under pure compression fatigue remains uncertain. In this study, compression fatigue tests under different peak stresses were carried out on smooth bars of fully annealed OFHC Copper. The purpose of these tests is to investigate not only the cyclic deformation response but also the possibility of crack nucleation without the stress concentrator. Results showed that overall the cyclic stress-strain response and microstructural evolution of OFHC Copper under pure compression fatigue exhibits rather dissimilar behaviour compared to those under symmetrical fatigue. The specimens hardened rapidly within 10 cycles under pure compression fatigue unlike the gradual cyclic hardening behaviour in symmetrical fatigue with the same peak stress amplitude. Compressive cyclic creep behaviour was also observed under the same testing conditions. Moreover, unlike conventional tension-compression fatigue, only moderate slip activity was detectable on the surface instead of typical PSB features detected from TEM observations. The surface observations has revealed that surface slip bands did not increase in number nor did they become more pronounced in height with increasing number of cycles. In addition, surface roughening by grain boundary extrusion was detected to become more severe as the cycling progressed. Therefore

  9. Dose rate measurements from radiopharmaceuticals: implications for nuclear medicine staff and for children with radioactive parents.

    PubMed

    Greaves, C D; Tindale, W B

    1999-02-01

    Following the introduction of a number of radiopharmaceuticals, we assessed the dose received by staff working in the nuclear medicine department and also by children who may be in close contact with a radioactive parent. We measured departure dose rates (microSv.h-1) at distances of 0.1, 0.5 and 1.0 m from the skin surface at the level of the thyroid, chest and bladder of patients undergoing the following nuclear medicine procedures: MUGA scans using 99Tcm-labelled red blood cells, myocardial perfusion scans using 99Tcm-labelled radiopharmaceuticals, lymphoscintigraphy using colloidal 99Tcm (Re) sulphide, bone scans using 99Tcm-labelled oxidronate, 111In-octreotide scans, 111In-labelled leukocyte studies and cardiac reinjection studies using 201Tl. The maximum dose rates at 0.1 m were those from MUGA studies (167.3 microSv.h-1) and myocardial perfusion studies (one-day protocol = 391.7 microSv.h-1, two-day protocol = 121.8 microSv.h-1). The implications of these dose rates on both technical and nursing staff are assessed. Also, the dose received by an infant in close contact with a parent following a nuclear medicine investigation was estimated.

  10. Cyclical components of local rainfall data

    NASA Astrophysics Data System (ADS)

    Mentz, R. P.; D'Urso, M. A.; Jarma, N. M.; Mentz, G. B.

    2000-02-01

    This paper reports on the use of a comparatively simple statistical methodology to study local short time series rainfall data. The objective is to help in agricultural planning, by diminishing the risks associated with some uncertainties affecting this business activity.The analysis starts by assuming a model of unobservable components, trend, cycle, seasonal and irregular, that is well known in many areas of application. When series are in the realm of business and economics, the statistical methods popularized by the US Census Bureau US National Bureau of Economic Research are used for seasonal and cyclical estimation, respectively. The flexibility of these methods makes them good candidates to be applied in the meteorological context, and this is done in this paper for a selection of monthly rainfall time series.Use of the results to help in analysing and forecasting cyclical components is emphasized. The results are interesting. An agricultural entrepreneur, or a group of them located in a single geographical region, will profit by systematically collecting information (monthly in our work) about rainfall, and adopting the scheme of analysis described in this paper.

  11. Rethinking progesterone regulation of female reproductive cyclicity

    PubMed Central

    Kubota, Kaiyu; Cui, Wei; Dhakal, Pramod; Wolfe, Michael W.; Rumi, M. A. Karim; Vivian, Jay L.; Roby, Katherine F.; Soares, Michael J.

    2016-01-01

    The progesterone receptor (PGR) is a ligand-activated transcription factor with key roles in the regulation of female fertility. Much has been learned of the actions of PGR signaling through the use of pharmacologic inhibitors and genetic manipulation, using mouse mutagenesis. Characterization of rats with a null mutation at the Pgr locus has forced a reexamination of the role of progesterone in the regulation of the female reproductive cycle. We generated two Pgr mutant rat models, using genome editing. In both cases, deletions yielded a null mutation resulting from a nonsense frame-shift and the emergence of a stop codon. Similar to Pgr null mice, Pgr null rats were infertile because of deficits in sexual behavior, ovulation, and uterine endometrial differentiation. However, in contrast to the reported phenotype of female mice with disruptions in Pgr signaling, Pgr null female rats exhibit robust estrous cycles. Cyclic changes in vaginal cytology, uterine histology, serum hormone levels, and wheel running activity were evident in Pgr null female rats, similar to wild-type controls. Furthermore, exogenous progesterone treatment inhibited estrous cycles in wild-type female rats but not in Pgr-null female rats. As previously reported, pharmacologic antagonism supports a role for PGR signaling in the regulation of the ovulatory gonadotropin surge, a result at variance with experimentation using genetic ablation of PGR signaling. To conclude, our findings in the Pgr null rat challenge current assumptions and prompt a reevaluation of the hormonal control of reproductive cyclicity. PMID:27035990

  12. Rethinking progesterone regulation of female reproductive cyclicity.

    PubMed

    Kubota, Kaiyu; Cui, Wei; Dhakal, Pramod; Wolfe, Michael W; Rumi, M A Karim; Vivian, Jay L; Roby, Katherine F; Soares, Michael J

    2016-04-12

    The progesterone receptor (PGR) is a ligand-activated transcription factor with key roles in the regulation of female fertility. Much has been learned of the actions of PGR signaling through the use of pharmacologic inhibitors and genetic manipulation, using mouse mutagenesis. Characterization of rats with a null mutation at the Pgr locus has forced a reexamination of the role of progesterone in the regulation of the female reproductive cycle. We generated two Pgr mutant rat models, using genome editing. In both cases, deletions yielded a null mutation resulting from a nonsense frame-shift and the emergence of a stop codon. Similar to Pgr null mice, Pgr null rats were infertile because of deficits in sexual behavior, ovulation, and uterine endometrial differentiation. However, in contrast to the reported phenotype of female mice with disruptions in Pgr signaling, Pgr null female rats exhibit robust estrous cycles. Cyclic changes in vaginal cytology, uterine histology, serum hormone levels, and wheel running activity were evident in Pgr null female rats, similar to wild-type controls. Furthermore, exogenous progesterone treatment inhibited estrous cycles in wild-type female rats but not in Pgr-null female rats. As previously reported, pharmacologic antagonism supports a role for PGR signaling in the regulation of the ovulatory gonadotropin surge, a result at variance with experimentation using genetic ablation of PGR signaling. To conclude, our findings in the Pgr null rat challenge current assumptions and prompt a reevaluation of the hormonal control of reproductive cyclicity.

  13. Effects of Cyclic Hydraulic Pressure on Osteocytes

    PubMed Central

    Liu, Chao; Zhao, Yan; Cheung, Wing-Yee; Gandhi, Ronak; Wang, Liyun; You, Lidan

    2010-01-01

    Bone is able to adapt its composition and structure in order to suit its mechanical environment. Osteocytes, bone cells embedded in the calcified matrix, are believed to be the mechanosensors and responsible for orchestrating the bone remodeling process. Recent in vitro studies have shown that osteocytes are able to sense and respond to substrate strain and fluid shear. However the capacity of osteocytes to sense cyclic hydraulic pressure (CHP) associated with physiological mechanical loading is not well understood. In this study, we subjected osteocyte-like MLO-Y4 cells to controlled CHP of 68 kPa at 0.5 Hz, and investigated the effects of CHP on intracellular calcium concentration, cytoskeleton organization, mRNA expression of genes related to bone remodeling, and osteocyte apoptosis. We found that osteocytes were able to sense CHP and respond by increased intracellular calcium concentration, altered microtubule organization, a time-dependent increase in COX-2 mRNA level and RANKL/OPG mRNA ratio, and decreased apoptosis. These findings support the hypothesis that loading induced cyclic hydraulic pressure in bone serves as a mechanical stimulus to osteocytes and may play a role in regulating bone remodeling in vivo. PMID:20149907

  14. Rf cavity primer for cyclic proton accelerators

    SciTech Connect

    Griffin, J.E.

    1988-04-01

    The purpose of this note is to describe the electrical and mechanical properites of particle accelerator rf cavities in a manner which will be useful to physics and engineering graduates entering the accelerator field. The discussion will be limited to proton (or antiproton) synchrotron accelerators or storage rings operating roughly in the range of 20 to 200 MHz. The very high gradient, fixed frequency UHF or microwave devices appropriate for electron machines and the somewhat lower frequency and broader bandwidth devices required for heavy ion accelerators are discussed extensively in other papers in this series. While it is common pratice to employ field calculation programs such as SUPERFISH, URMEL, or MAFIA as design aids in the development of rf cavities, we attempt here to elucidate various of the design parameters commonly dealt with in proton machines through the use of simple standing wave coaxial resonator expressions. In so doing, we treat only standing wave structures. Although low-impedance, moderately broad pass-band travelling wave accelerating systems are used in the CERN SPS, such systems are more commonly found in linacs, and they have not been used widely in large cyclic accelerators. Two appendices providing useful supporting material regarding relativistic particle dynamics and synchrotron motion in cyclic accelerators are added to supplement the text.

  15. Effects of cyclic hydraulic pressure on osteocytes.

    PubMed

    Liu, Chao; Zhao, Yan; Cheung, Wing-Yee; Gandhi, Ronak; Wang, Liyun; You, Lidan

    2010-05-01

    Bone is able to adapt its composition and structure in order to suit its mechanical environment. Osteocytes, bone cells embedded in the calcified matrix, are believed to be the mechanosensors and responsible for orchestrating the bone remodeling process. Recent in vitro studies have shown that osteocytes are able to sense and respond to substrate strain and fluid shear. However the capacity of osteocytes to sense cyclic hydraulic pressure (CHP) associated with physiological mechanical loading is not well understood. In this study, we subjected osteocyte-like MLO-Y4 cells to controlled CHP of 68 kPa at 0.5 Hz, and investigated the effects of CHP on intracellular calcium concentration, cytoskeleton organization, mRNA expression of genes related to bone remodeling, and osteocyte apoptosis. We found that osteocytes were able to sense CHP and respond by increased intracellular calcium concentration, altered microtubule organization, a time-dependent increase in COX-2 mRNA level and RANKL/OPG mRNA ratio, and decreased apoptosis. These findings support the hypothesis that loading induced cyclic hydraulic pressure in bone serves as a mechanical stimulus to osteocytes and may play a role in regulating bone remodeling in vivo.

  16. Nutrition Marketing on Food Labels

    ERIC Educational Resources Information Center

    Colby, Sarah E.; Johnson, LuAnn; Scheett, Angela; Hoverson, Bonita

    2010-01-01

    Objective: This research sought to determine how often nutrition marketing is used on labels of foods that are high in saturated fat, sodium, and/or sugar. Design and Setting: All items packaged with food labels (N = 56,900) in all 6 grocery stores in Grand Forks, ND were surveyed. Main Outcome Measure(s): Marketing strategy, nutrient label…

  17. Nutrition Marketing on Food Labels

    ERIC Educational Resources Information Center

    Colby, Sarah E.; Johnson, LuAnn; Scheett, Angela; Hoverson, Bonita

    2010-01-01

    Objective: This research sought to determine how often nutrition marketing is used on labels of foods that are high in saturated fat, sodium, and/or sugar. Design and Setting: All items packaged with food labels (N = 56,900) in all 6 grocery stores in Grand Forks, ND were surveyed. Main Outcome Measure(s): Marketing strategy, nutrient label…

  18. Dependence of the Excitability of Pituitary Cells on Cyclic Nucleotides

    PubMed Central

    Stojilkovic, Stanko S.; Kretschmannova, Karla; Tomic, Melanija; Stratakis, Constantine A.

    2012-01-01

    Cyclic 3′,5′-adenosine monophosphate and cyclic 3′,5′-guanosine monophosphate are intracellular (second) messengers that are produced from the nucleotide triphosphates by a family of enzymes consisting of adenylyl and guanylyl cyclases. These enzymes are involved in a broad array of signal transduction pathways mediated by the cyclic nucleotide monophosphates and their kinases, which control multiple aspects of cell function through the phosphorylation of protein substrates. Here, we review the findings and working hypotheses on the role of the cyclic nucleotides and their kinases in the control of electrical activity of the endocrine pituitary cells and the plasma membrane channels involved in this process. PMID:22564128

  19. May Cyclic Nucleotides Be a Source for Abiotic RNA Synthesis?

    NASA Astrophysics Data System (ADS)

    Costanzo, Giovanna; Pino, Samanta; Botta, Giorgia; Saladino, Raffaele; di Mauro, Ernesto

    2011-12-01

    Nucleic bases are obtained by heating formamide in the presence of various catalysts. Formamide chemistry also allows the formation of acyclonucleosides and the phosphorylation of nucleosides in every possible position, also affording 2',3' and 3',5' cyclic forms. We have reported that 3',5' cyclic GMP and 3',5' cyclic AMP polymerize in abiotic conditions yielding short oligonucleotides. The characterization of this reaction is being pursued, several of its parameters have been determined and experimental caveats are reported. The yield of non-enzymatic polymerization of cyclic purine nucleotides is very low. Polymerization is strongly enhanced by the presence of base-complementary RNA sequences.

  20. Health claims on food labels.

    PubMed

    Tollefson, L

    1994-03-01

    Food and drug law requires that the ingredients in most foods be disclosed on their labels, but until recently there was no requirement that nutrition information be provided. The Nutrition Labeling and Education Act of 1990 (NLEA), passed on November 8, 1990, mandated the Food and Drug Administration to establish regulations requiring most foods to have a uniform nutrition label showing the amount of calories, calories from fat, total fat, saturated fatty acids, cholesterol, total carbohydrates, complex carbohydrates, sugars, fiber, protein, and sodium. The Act also establishes the circumstances under which content claims and disease claims may be made about nutrients in food. This paper briefly discusses recent changes in the food label brought about by the NLEA and focuses on health claims on food labels.

  1. Evidence Against the Presence of 3′, 5′-Cyclic Adenosine Monophosphate and Relevant Enzymes in Lactobacillus plantarum

    PubMed Central

    Sahyoun, N.; Durr, I. F.

    1972-01-01

    Analysis of cells of Lactobacillus plantarum, starved or undergoing induction, showed no 3′, 5′-cyclic adenosine monophosphate (cAMP). Neither adenyl cyclase nor 3′, 5′-cAMP phosphodiesterase was detected in extracts. Extracts of L. plantarum did not inhibit these two enzymes of Escherichia coli K-12, strain W1435. Incubation of adenosine triphosphate (ATP)-U-14C with cells or various cell-free fractions of L. plantarum did not produce labeled 3′, 5′-cAMP. Of various 3′, 5′-cyclic and acyclic nucleotides tested, only 3′, 5′-cAMP, ATP, and yeast adenylic acid stimulated l-arabinose isomerase. Yeast adenylic acid was two to four times as effective as 3′, 5′-cAMP or ATP. 2′, 3′-cAMP was not effective. PMID:4342815

  2. Phospholipid metabolism in zymosan stimulated human monocytes: modulation by cyclic AMP (cAMP)

    SciTech Connect

    Godfrey R.W.; Manzi, R.M.; Hoffstein, S.T.

    1986-05-01

    Oxygenated products of arachidonic acid (AA) are critical components in the development of the inflammatory response. Monocytes exposed to inflammatory stimuli are capable of converting free AA into these bioactive molecules. However, the limiting step in the formation of these compounds is thought to be the mechanism responsible for the release of esterified AA from phospholipids. When (/sup 3/H) AA labeled monocytes were challenged with opsonized zymosan, 28 +/- 2% of the incorporated counts were released compared to 8 +/- 1% for the control. Upon pretreatment with isobutyl methyl xanthine (IBMX) or dibutyrl cyclic AMP (d-cAMP) zymosan stimulated AA release was markedly reduced. The IC/sub 50/'s were 4 x 10/sup -4/M and 7 x 10/sup -4/M respectively. Analysis of (/sup 3/H) AA incorporation into cellular phospholipids showed that phosphatidylcholine (PC) and phosphatidylinositol (PI) were the primary pools labeled. Loss of label from both of these pools was evident after exposure to zymosan, however, pretreatment of cells with IBMX or d-cAMP inhibited release of (/sup 3/H)AA from the PC pool but not from the PI pool. The results show that human monocytes challenged with opsonized zymosan release arachidonic acid via cAMP-dependent and independent pathways. Furthermore, they suggest that a phospholipase activity (possibly A/sub 2/) against PC is modulated by cAMP.

  3. FRET-based binding assay between a fluorescent cAMP analogue and a cyclic nucleotide-binding domain tagged with a CFP.

    PubMed

    Romero, Francisco; Santana-Calvo, Carmen; Sánchez-Guevara, Yoloxochitl; Nishigaki, Takuya

    2017-07-22

    The cyclic nucleotide-binding domain (CNBD) functions as a regulatory domain of many proteins involved in cyclic nucleotide signalling. We developed a straightforward and reliable binding assay based on intermolecular fluorescence resonance energy transfer (FRET) between an adenosine-3', 5'-cyclic monophosphate analogue labelled with fluorescein and a recombinant CNBD of human EPAC1 tagged with a cyan fluorescence protein (CFP). The high FRET efficiency of this method (~ 80%) allowed us to perform several types of binding experiments with nanomolar range of sample using conventional equipment. In addition, the CFP tag on the CNBD enabled us to perform a specific binding experiment using an unpurified protein. Considering these advantages, this technique is useful to study poorly characterized CNBDs. © 2017 Federation of European Biochemical Societies.

  4. 21 CFR 201.72 - Potassium labeling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Potassium labeling. 201.72 Section 201.72 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.72 Potassium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the potassium content...

  5. 21 CFR 201.72 - Potassium labeling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Potassium labeling. 201.72 Section 201.72 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.72 Potassium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the potassium content...

  6. 21 CFR 201.72 - Potassium labeling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Potassium labeling. 201.72 Section 201.72 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.72 Potassium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the potassium content...

  7. 16 CFR 1633.12 - Labeling.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the Standard shall bear a permanent, conspicuous, and legible label(s) containing the following... with black text. The label text shall comply with the following format requirements: (1) All... as needed for varying information. The label must be white with black text. The label shall contain...

  8. 21 CFR 201.64 - Sodium labeling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... contains sodium bicarbonate, sodium phosphate, or sodium biphosphate as an active ingredient for oral... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Sodium labeling. 201.64 Section 201.64 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.64 Sodium labeling. (a) The labeling of...

  9. 21 CFR 201.64 - Sodium labeling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... contains sodium bicarbonate, sodium phosphate, or sodium biphosphate as an active ingredient for oral... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Sodium labeling. 201.64 Section 201.64 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.64 Sodium labeling. (a) The labeling of...

  10. 21 CFR 201.64 - Sodium labeling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... contains sodium bicarbonate, sodium phosphate, or sodium biphosphate as an active ingredient for oral... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Sodium labeling. 201.64 Section 201.64 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.64 Sodium labeling. (a) The labeling of...

  11. 21 CFR 201.72 - Potassium labeling.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Potassium labeling. 201.72 Section 201.72 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.72 Potassium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the potassium...

  12. 21 CFR 201.71 - Magnesium labeling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Magnesium labeling. 201.71 Section 201.71 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.71 Magnesium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium content...

  13. 21 CFR 201.71 - Magnesium labeling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Magnesium labeling. 201.71 Section 201.71 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.71 Magnesium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium content...

  14. 21 CFR 201.71 - Magnesium labeling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Magnesium labeling. 201.71 Section 201.71 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.71 Magnesium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium content...

  15. Labeled Cocaine Analogs

    DOEpatents

    Goodman, Mark M.; Shi, Bing Zhi; Keil, Robert N.

    1999-01-26

    Novel compounds having the structure: ##STR1## where X in .beta. configuration is phenyl, naphthyl; 2,3 or 4-iodophenyl; 2,3 or 4-(trimethylsilyl)phenyl; 3,4,5 or 6-iodonaphthyl; 3,4,5 or 6-(trimethylsilyl)naphthyl; 2,3 or 4-(trialkylstannyl)phenyl; or 3,4,5 or 6-(trialkylstannyl)naphthyl Y in .beta. configuration is Y.sub.1 or Y.sub.2, where Y.sub.1 is 2-fluoroethoxy, 3-fluoropropoxy, 4-fluorobutoxy, 2-fluorocyclopropoxy, 2 or 3-fluorocyclobutoxy, R,S 1'-fluoroisopropoxy, R 1'-fluoroisopropoxy, S 1'-fluoroisopropoxy, 1',3'-difluoroisopropoxy, R,S 1'-fluoroisobutoxy, R 1'-fluoroisobutoxy, S 1'-fluoroisobutoxy, R,S 4'-fluoroisobutoxy, R 4'-fluoroisobutoxy, S 4'-fluoroisobutoxy, or 1',1'-di(fluoromethyl)isobutoxy, and Y.sub.2 is 2-methanesulfonyloxy ethoxy, 3-methanesulfonyloxy propoxy, 4-methanesulfonyloxy butoxy, 2-methanesulfonyloxy cyclopropoxy, 2 or 3-methanesulfonyloxy cyclobutoxy, 1'methanesulfonyloxy isopropoxy, 1'-fluoro, 3'-methanesulfonyloxy isopropoxy, 1'-methanesulfonyloxy, 3'-fluoro isopropoxy, 1'-methanesulfonyloxy isobutoxy, or 4'-methanesulfonyloxy isobutoxy bind dopamine transporter protein and can be labeled with .sup.18 F or .sup.123 I for imaging.

  16. Synthesis Of Labeled Metabolites

    DOEpatents

    Martinez, Rodolfo A.; Silks, III, Louis A.; Unkefer, Clifford J.; Atcher, Robert

    2004-03-23

    The present invention is directed to labeled compounds, for example, isotopically enriched mustard gas metabolites including: [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1,1'-sulfonylbis[2-(methylthio); [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1-[[2-(methylsulfinyl)ethyl]sulfonyl]-2-(methylthio); [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1,1'-sulfonylbis[2-(methylsulfinyl)]; and, 2,2'-sulfinylbis([1,2-.sup.13 C.sub.2 ]ethanol of the general formula ##STR1## where Q.sup.1 is selected from the group consisting of sulfide (--S--), sulfone (--S(O)--), sulfoxide (--S(O.sub.2)--) and oxide (--O--), at least one C* is .sup.13 C, X is selected from the group consisting of hydrogen and deuterium, and Z is selected from the group consisting of hydroxide (--OH), and --Q.sup.2 --R where Q.sup.2 is selected from the group consisting of sulfide (--S--), sulfone(--S(O)--), sulfoxide (--S(O.sub.2)--) and oxide (--O--), and R is selected from the group consisting of hydrogen, a C.sub.1 to C.sub.4 lower alkyl, and amino acid moieties, with the proviso that when Z is a hydroxide and Q.sup.1 is a sulfide, then at least one X is deuterium.

  17. Biologic activity of cyclic and caged phosphates: a review.

    PubMed

    Lorke, Dietrich E; Stegmeier-Petroianu, Anka; Petroianu, Georg A

    2017-01-01

    The recognition in the early 1960s by Morifusa Eto that tri-o-cresyl phosphate (TOCP) is hydroxylated by the cytochrome P450 system to an intermediate that spontaneously cyclizes to a neurotoxic phosphate (saligenin phosphate ester) ignited the interest in this group of compounds. Only the ortho isomer can cyclize and clinically cause Organo Phosphate Induced Delayed Neurotoxicity (OPIDN); the meta and para isomers of tri-cresyl phosphate are not neuropathic because they are unable to form stable cyclic saligenin phosphate esters. This review identifies the diverse biological effects associated with various cyclic and caged phosphates and phosphonates and their possible use. Cyclic compounds that inhibit acetylcholine esterase (AChE), such as salithion, can be employed as pesticides. Others are neurotoxic, most probably because of inhibition of neuropathy target esterase (NTE). Cyclic phosphates that inhibit lipases, the cyclipostins, possibly represent promising therapeutic avenues for the treatment of type 2 diabetes mellitus and/or microbial infections; those compounds inhibiting β-lactamase may prevent bacterial resistance against β-lactam antibiotics. Naturally occurring cyclic phosphates, such as cyclic AMP, cyclic phosphatidic acid and the ryanodine receptor modulator cyclic adenosine diphosphate ribose, play an important physiological role in signal transduction. Moreover, some cyclic phosphates are GABA-antagonists, while others are an essential component of Molybdenum-containing enzymes. Some cyclic phosphates (cyclophosphamide, ifosfamide) are clinically used in tumor therapy, while the coupling of therapeutic agents with other cyclic phosphates (HepDirect® Technology) allows drugs to be targeted to specific organs. Possible clinical applications of these compounds are considered. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Cyclic vomiting presentations following marijuana liberalization in Colorado.

    PubMed

    Kim, Howard S; Anderson, John D; Saghafi, Omeed; Heard, Kennon J; Monte, Andrew A

    2015-06-01

    Case reports have described a syndrome of cyclic vomiting associated with chronic marijuana use, termed cannabinoid hyperemesis syndrome. The primary objective was to determine the prevalence of patients presenting with cyclic vomiting before and after the liberalization of medical marijuana in Colorado in 2009. The secondary objective was to describe the odds of marijuana use among cyclic vomiting visits in these same time periods. This was a cross-sectional study of cyclic vomiting visits to the emergency department (ED) before and after marijuana liberalization. ED visits with International Classification of Diseases, ninth revision, coding for cyclic vomiting or that met diagnostic criteria for cyclic vomiting by the Rome III criteria were included. The authors reviewed 2,574 visits and identified 36 patients diagnosed with cyclic vomiting over 128 visits. The prevalence of cyclic vomiting visits increased from 41 per 113,262 ED visits to 87 per 125,095 ED visits after marijuana liberalization, corresponding to a prevalence ratio of 1.92 (95% confidence interval [CI] = 1.33 to 2.79). Patients with cyclic vomiting in the postliberalization period were more likely to have marijuana use documented than patients in the preliberalization period (odds ratio = 3.59, 95% CI = 1.44 to 9.00). The prevalence of cyclic vomiting presentations nearly doubled after the liberalization of medical marijuana. Patients presenting with cyclic vomiting in the postliberalization period were more likely to endorse marijuana use, although it is unclear whether this was secondary to increased marijuana use, more accurate marijuana reporting, or both. © 2015 by the Society for Academic Emergency Medicine.

  19. Investigation of Cyclic Deformation and Fatigue of Polycrystalline Cu under Pure Compression Cyclic Loading Conditions

    NASA Astrophysics Data System (ADS)

    Hsu, Tzu-Yin Jean

    It is commonly accepted that fatigue crack is initiated under tensile fatigue stresses. However, practical examples demonstrate that cracks may initiate under pure compressive fluctuating loads, e.g. the failures observed in aircraft landing gear frames. As the mechanism of such failures is rarely investigated, there is very limited or non-existent knowledge pool on cyclic deformation response under pure compressive fatigue condition. Our recent work verified that fatigue cracks may nucleate from stress concentration sites under pure compression fatigue, but whether or not a form of stress concentration is always needed to initiate a crack remains uncertain. In this study, compression fatigue tests under different peak stresses were carried out on smooth bars of fully annealed OFHC Copper. The purpose of these tests is to investigate not only the cyclic deformation response but also the possibility of crack nucleation without the stress concentrator. Results showed that overall the cyclic stress-strain response and microstructural evolution of OFHC Copper under pure compression fatigue exhibits rather dissimilar behaviour compared to those under symmetrical fatigue. The specimens hardened rapidly within 10 cycles under pure compression fatigue unlike the gradual cyclic hardening behaviour in symmetrical fatigue with the same peak stress amplitude. Compressive cyclic creep behaviour was also observed. Moreover, TEM observation showed that only moderate slip activity was detectable on the surface instead of typical PSB features. The surface observations revealed that surface slip bands did not increase in number nor height as cycling progressed. In addition, surface roughening by grain boundary extrusion was detected to become more severe with further cycling. Therefore, the plastic strain accommodated within the samples was not mainly related to dislocation activities. Instead, the mechanism of cyclic creep response for pure compression fatigue was correlated and

  20. Performance and carbon turnover in fast- and slow-growing broilers submitted to cyclic heat stress and fed on high-protein diets.

    PubMed

    Campos, D M B; Macari, M; Fernadez-Alarcon, M F; Nogueira, W C L; de Souza, F A; Hada, F H; Lunedo, R; Denadai, J C

    2016-01-01

    Two experiments were conducted to test the hypothesis that when using similar protein/amino acid diets and environment temperature conditions, the performance and carbon turnover in muscle and liver tissues, as measured by the incorporation of stable isotopes ((13)C/(12)C), must be different between fast-growing Cobb 500® and slow-growing Label Rouge broilers. For both experiments (Cobb and Label Rouge), 21-d-old birds were distributed in a completely randomised, 3 × 3 factorial design; three environmental temperatures (cyclic heat stress ad libitum, 22°C ad libitum, and 22°C restricted) and three crude protein concentrations (189.1, 210 and 220 g/kg CP) were used. The Cobb 500® had better performance with higher concentrations of crude protein. Cyclic heat stress (a temperature factor), negatively affected this genetic strain's performance. For the Label Rouge birds, the crude protein concentrations in the diet presented inconsistent results and cyclic heat stress did not affect the performance. The carbon turnover rate was affected in the Cobb 500® strain, with a high protein content reducing carbon turnover in the evaluated tissues (liver and muscles). Feed intake had a greater impact on carbon turnover rates than cyclic heat stress. The Label Rouge birds were not affected by the evaluated factors, suggesting that genetic improvement has a leading role on tissue carbon turnover. There is a genetic influence on carbon turnover in the liver and muscle tissues of broiler chickens. In addition, genetically fast-growing broilers are more susceptible to variations in diet composition and environmental temperature than less rapidly growing animals.

  1. The prognosis of cyclical vomiting syndrome

    PubMed Central

    Dignan, F; Symon, D; AbuArafeh, I; Russell, G

    2001-01-01

    AIMS—The medium term prognosis of cyclical vomiting syndrome (CVS) was studied to determine the proportion of affected individuals who had gone on to develop headaches fulfilling the International Headache Society criteria for migraine.
METHODS—Twenty six (76%) of 34 CVS sufferers identified from the authors' clinical records were traced, and all agreed to participate. Each child was matched to a control, and telephone interviews were conducted using a standardised questionnaire.
RESULTS—Thirteen (50%) of the subjects had continuing CVS and/or migraine headaches while the remainder were currently asymptomatic. The prevalence of past or present migraine headaches in subjects (46%) was significantly higher than in the control population (12%).
CONCLUSION—Results support the concept that CVS is closely related to migraine.

 PMID:11124785

  2. Treatment of staphylococcal infections with cyclic lipopeptides.

    PubMed

    Eisenstein, B I

    2008-03-01

    Daptomycin is the first of a new class of antibiotics, the cyclic lipopeptides, for which a novel mechanism of action is hypothesised. Owing to its mode of action, daptomycin is rapidly bactericidal without being bacteriolytic, is active against static- and growing-phase bacteria, and has a low resistance rate in vitro. Phase III clinical trials have demonstrated that daptomycin is as effective as standard therapy for the treatment of complicated skin and soft-tissue infections associated with Gram-positive infections, and daptomycin-treated patients benefited from a reduced time to clinical resolution. Daptomycin has also been shown to be as effective as standard therapy in the treatment of bacteraemia associated with Staphylococcus aureus, with or without endocarditis. These results indicate that daptomycin is a useful therapeutic option for treating Gram-positive infections, particularly those caused by S. aureus.

  3. OBSERVATIONS ON A CASE OF CYCLIC ALBUMINURIA

    PubMed Central

    Mendel, Lafayette B.; Hooker, Donald B.

    1901-01-01

    The preceding observations record a new instance of the occurrence of cyclic albuminuria in an otherwise apparently healthy young man. The typical course of the proteid excretion from hour to hour under various conditions has been reviewed and its independence of the changes in diet or muscular work pointed out. No relationship between the volume of urine eliminated and the quantity of proteid excreted has been ascertained. The specific effect of the horizontal posture in dispelling the albuminuria is the most interesting feature observed. The attempt to refer this to attendant circulatory changes in the kidneys is, for the present, no more than an interesting speculation. See PDF for Structure See PDF for Structure PMID:19866962

  4. Monitoring thermoplastic composites under cyclic bending tests

    NASA Astrophysics Data System (ADS)

    Boccardi, Simone; Meola, Carosena; Carlomagno, Giovanni Maria; Simeoli, Giorgio; Acierno, Domenico; Russo, Pietro

    2016-05-01

    This work is concerned with the use of infrared thermography to visualize temperature variations linked to thermo-elastic effects developing over the surface of a specimen undergoing deflection under bending tests. Several specimens are herein considered, which involve change of matrix and/or reinforcement. More specifically, the matrix is either a pure polypropylene, or a polypropylene added with a certain percentage of compatibilizing agent; the reinforcement is made of glass, or jute. Cyclic bending tests are carried out by the aid of an electromechanical actuator. Each specimen is viewed, during deflection, from one surface by an infrared imaging device. As main finding the different specimens display surface temperature variations which depend on the type of material in terms of both matrix and reinforcement.

  5. Extinction in four species cyclic competition

    NASA Astrophysics Data System (ADS)

    Intoy, Ben; Pleimling, Michel

    2013-08-01

    When four species compete stochastically in a cyclic way, the formation of two teams of mutually neutral partners is observed. In this paper we study through numerical simulations the extinction processes that can take place in this system both in the well mixed case as well as on different types of lattices. The different routes to extinction are revealed by the probability distribution of the domination time, i.e. the time needed for one team to fully occupy the system. If swapping is allowed between neutral partners, then the probability distribution is dominated by very long-lived states where a few very large domains persist, each domain being occupied by a mix of individuals from species that form one of the teams. Many aspects of the possible extinction scenarios are lost when only considering averaged quantities, such as for example the mean domination time.

  6. Cyclic phosphatidic acid - a unique bioactive phospholipid.

    PubMed

    Fujiwara, Yuko

    2008-09-01

    Cyclic phosphatidic acid (CPA) is a naturally occurring analog of the growth factor-like phospholipid mediator, lysophosphatidic acid (LPA). The sn-2 hydroxy group of CPA forms a 5-membered ring with the sn-3 phosphate. CPA affects numerous cellular functions, including anti-mitogenic regulation of the cell cycle, induction of stress fiber formation, inhibition of tumor cell invasion and metastasis, and regulation of differentiation and survival of neuronal cells. Interestingly, many of these cellular responses caused by CPA oppose those of LPA despite the activation of apparently overlapping receptor populations. Since the early 1990s, studies on CPA actions gradually developed, and we are now beginning to understand the importance of this lipid. In this review, we focus on the current knowledge about CPA, including enzymatic formation of CPA, unique biological activities and biological targets of CPA, and we also explore metabolically stabilized CPA analogs.

  7. Protein Misfolding Cyclic Amplification of Infectious Prions.

    PubMed

    Moda, Fabio

    2017-01-01

    Transmissible spongiform encephalopathies, or prion diseases, are a group of incurable disorders caused by the accumulation of an abnormally folded prion protein (PrP(Sc)) in the brain. According to the "protein-only" hypothesis, PrP(Sc) is the infectious agent able to propagate the disease by acting as a template for the conversion of the correctly folded prion protein (PrP(C)) into the pathological isoform. Recently, the mechanism of PrP(C) conversion has been mimicked in vitro using an innovative technique named protein misfolding cyclic amplification (PMCA). This technology represents a great tool for studying diverse aspects of prion biology in the field of basic research and diagnosis. Moreover, PMCA can be expanded for the study of the misfolding process associated to other neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and frontotemporal lobar degeneration. © 2017 Elsevier Inc. All rights reserved.

  8. [Cyclic imine toxin gymnodimine: a review].

    PubMed

    Liu, Ren-yan; Liang, Yu-bo

    2009-09-01

    Gymnodimine (GYM), an algal toxin first detected from New Zealand oysters in 1994, is identified as a cyclic imine toxin and produced by Karenia selliformis, with imino nitrogen attached on loop-coil. Imine is the poisonous functional group of the toxin. GYM has a low oral toxicity, but its acute lethal toxicity of intra-peritoneal injection for mice is very high. Up to now, few reports have been published on the detailed information about the toxicity mechanism of GYM. Based on limited literatures, this paper reviewed the GYM's structure, producer, toxicity mechanism, carrying animals, geological distribution, degradation metabolism, dose-effect relation, and risk evaluation, and proposed the further research directions on algal toxin.

  9. KP hierarchy for the cyclic quiver

    NASA Astrophysics Data System (ADS)

    Chalykh, Oleg; Silantyev, Alexey

    2017-07-01

    We introduce a generalisation of the KP hierarchy, closely related to the cyclic quiver and the Cherednik algebra Hk(Zm ) . This hierarchy depends on m parameters (one of which can be eliminated), with the usual KP hierarchy corresponding to the m = 1 case. Generalising the result of Wilson [Invent. Math. 133(1), 1-41 (1998)], we show that our hierarchy admits solutions parameterised by suitable quiver varieties. The pole dynamics for these solutions is shown to be governed by the classical Calogero-Moser system for the wreath-product Zm≀Sn and its new spin version. These results are further extended to the case of the multi-component hierarchy.

  10. Cyclic steps incised on experimental bedrock

    NASA Astrophysics Data System (ADS)

    Yokokawa, M.; Kyogoku, A.; Kotera, A.; Izumi, N.

    2013-12-01

    In rivers flowing in mountain areas, a series of steps are often observed on bedrock. They are thought to be cyclic steps formed due to erosion of bedrock, which should be driven by abrasion due to bedload sediment transport. We demonstrated a series of flume experiments of the formation of cyclic steps on bedrock by abrasion due to bedload transportation using weak mortar as the model bedrock. We also compared the shapes of the steps reproduced in the experiments with those obtained in the analysis. The experiments were conducted using a 1.5 m long, 2 cm wide, and 20 cm deep flume made of glass in Osaka Institute of Technology. The flume has 10-cm-high weirs at both ends, so that there is a 10-cm-deep reservoir. We put mortar into the reservoir and hardened it. In order to make a highly erodible mortar, we casted the mortar with extremely low amount of cement. The ratio of cement, sand (0.2 mm in diameter), and water is x:150:50 (x ranges 1-3). The flume is tilted by 10 degrees. The water and colored sand is supplied from a head tank to the upstream end of the flume, flows on 'model bedrock' in the flume, and was dropped from the downstream end. We observed morphological changes of the surface of the bedrock by photos. We also used a laser displacement sensor to measure the surface topography of the 'model bedrock' before and after each run. The configuration of steps largely depends on the hardness of model bedrocks. In the case of the softest model bedrock (cement-sand-water ratio is 1:150:50) with small amount of sand, long-drawn potholes tend to be formed. Clear cyclic steps are formed on harder model bedrocks with large cement-sand-water ratios such as 2:150:50 and 3:150:50. When a series of steps are formed on the bed, typical wavelength and wave height are approximately 20 cm, and 2 - 3 cm, respectively. The general shape of a step is characterized by a relatively long downward-inclined slope just upstream of a short upward-inclined slope. The feature of

  11. A cyclic universe approach to fine tuning

    DOE PAGES

    Alexander, Stephon; Cormack, Sam; Gleiser, Marcelo

    2016-04-05

    We present a closed bouncing universe model where the value of coupling constants is set by the dynamics of a ghost-like dilatonic scalar field. We show that adding a periodic potential for the scalar field leads to a cyclic Friedmann universe where the values of the couplings vary randomly from one cycle to the next. While the shuffling of values for the couplings happens during the bounce, within each cycle their time-dependence remains safely within present observational bounds for physically-motivated values of the model parameters. Our model presents an alternative to solutions of the fine tuning problem based on stringmore » landscape scenarios. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).« less

  12. Planck 2013 results support the cyclic universe

    NASA Astrophysics Data System (ADS)

    Lehners, Jean-Luc; Steinhardt, Paul J.

    2013-06-01

    We show that results from the Planck satellite reported in 2013 are consistent with cyclic models of the Universe for natural parameter ranges (i.e. order unity dimensionless coefficients), assuming the standard entropic mechanism for generating curvature perturbations. With improved precision, forthcoming results from Planck and other experiments should be able to test the remaining parameter range and confirm or refute the core predictions, i.e. no observable primordial B-mode polarization and detectable local non-Gaussianity. A new prediction, given the Planck 2013 constraints on the bispectrum, is a sharp constraint on the local trispectrum parameter gNL; namely, the currently best-understood models predict it is negative, with gNL≲-1700.

  13. Algorithms for Labeling Focus Regions.

    PubMed

    Fink, M; Haunert, Jan-Henrik; Schulz, A; Spoerhase, J; Wolff, A

    2012-12-01

    In this paper, we investigate the problem of labeling point sites in focus regions of maps or diagrams. This problem occurs, for example, when the user of a mapping service wants to see the names of restaurants or other POIs in a crowded downtown area but keep the overview over a larger area. Our approach is to place the labels at the boundary of the focus region and connect each site with its label by a linear connection, which is called a leader. In this way, we move labels from the focus region to the less valuable context region surrounding it. In order to make the leader layout well readable, we present algorithms that rule out crossings between leaders and optimize other characteristics such as total leader length and distance between labels. This yields a new variant of the boundary labeling problem, which has been studied in the literature. Other than in traditional boundary labeling, where leaders are usually schematized polylines, we focus on leaders that are either straight-line segments or Bezier curves. Further, we present algorithms that, given the sites, find a position of the focus region that optimizes the above characteristics. We also consider a variant of the problem where we have more sites than space for labels. In this situation, we assume that the sites are prioritized by the user. Alternatively, we take a new facility-location perspective which yields a clustering of the sites. We label one representative of each cluster. If the user wishes, we apply our approach to the sites within a cluster, giving details on demand.

  14. Label Review Training: Module 1: Label Basics, Page 5

    EPA Pesticide Factsheets

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment.

  15. 76 FR 75809 - Prior Label Approval System: Generic Label Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... Protection Reference Center was launched as a Web page in February 1999. The Web page includes a PowerPoint presentation titled ``Labeling 101,'' which is used by the Agency as a teaching tool at workshops on meat and...

  16. Label Review Training: Module 1: Label Basics, Page 2

    EPA Pesticide Factsheets

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment.

  17. Label Review Training: Module 1: Label Basics, Page 9

    EPA Pesticide Factsheets

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment.

  18. Label Review Training: Module 1: Label Basics, Page 8

    EPA Pesticide Factsheets

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human he

  19. Label Review Training: Module 1: Label Basics, Page 6

    EPA Pesticide Factsheets

    Page 6, Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment

  20. Label Review Training: Module 1: Label Basics, Page 4

    EPA Pesticide Factsheets

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment.

  1. Label Review Training: Module 1: Label Basics, Page 3

    EPA Pesticide Factsheets

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment.

  2. 21 CFR 331.80 - Professional labeling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... HUMAN USE ANTACID PRODUCTS FOR OVER-THE-COUNTER (OTC) HUMAN USE Labeling § 331.80 Professional labeling..., muscle weakness, and osteomalacia. (b) Professional labeling for an antacid-antiflatulent combination...

  3. 21 CFR 331.80 - Professional labeling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HUMAN USE ANTACID PRODUCTS FOR OVER-THE-COUNTER (OTC) HUMAN USE Labeling § 331.80 Professional labeling..., muscle weakness, and osteomalacia. (b) Professional labeling for an antacid-antiflatulent combination...

  4. 21 CFR 331.80 - Professional labeling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... HUMAN USE ANTACID PRODUCTS FOR OVER-THE-COUNTER (OTC) HUMAN USE Labeling § 331.80 Professional labeling..., muscle weakness, and osteomalacia. (b) Professional labeling for an antacid-antiflatulent combination...

  5. Mobile Application for Pesticide Label Matching

    EPA Pesticide Factsheets

    The label matching application will give inspectors the ability to instantly compare pesticide product labels against state and federal label databases via their cell phone, tablet or other mobile device.

  6. 40 CFR 94.212 - Labeling.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... shall be of a color that contrasts with the background of the label: (1) The label heading: Marine...) to be designated as Blue Sky Series engines must contain the statement on the label: “Blue Sky...

  7. 40 CFR 94.212 - Labeling.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... shall be of a color that contrasts with the background of the label: (1) The label heading: Marine...) to be designated as Blue Sky Series engines must contain the statement on the label: “Blue Sky...

  8. 40 CFR 94.212 - Labeling.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... shall be of a color that contrasts with the background of the label: (1) The label heading: Marine...) to be designated as Blue Sky Series engines must contain the statement on the label: “Blue Sky...

  9. 49 CFR 172.442 - CORROSIVE label.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS HAZARDOUS MATERIALS TABLE, SPECIAL... SECURITY PLANS Labeling § 172.442 CORROSIVE label. (a) Except for size and color, the CORROSIVE label...

  10. 49 CFR 172.442 - CORROSIVE label.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS HAZARDOUS MATERIALS TABLE, SPECIAL... SECURITY PLANS Labeling § 172.442 CORROSIVE label. (a) Except for size and color, the CORROSIVE label...

  11. 49 CFR 172.442 - CORROSIVE label.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS HAZARDOUS MATERIALS TABLE, SPECIAL... SECURITY PLANS Labeling § 172.442 CORROSIVE label. (a) Except for size and color, the CORROSIVE label...

  12. Soil Fumigant Labels - Dimethyl Disulfide (DMDS)

    EPA Pesticide Factsheets

    Search by EPA registration number, product name, or company and follow the link to the Pesticide Product Labeling System (PPLS) for label details. Updated labels include new safety requirements for buffer zones and related measures.

  13. 21 CFR 1302.04 - Location and size of symbol on label and labeling.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Location and size of symbol on label and labeling... AND PACKAGING REQUIREMENTS FOR CONTROLLED SUBSTANCES § 1302.04 Location and size of symbol on label and labeling. The symbol shall be prominently located on the label or the labeling of the commercial...

  14. 78 FR 24211 - Draft Guidance for Industry on Safety Considerations for Container Labels and Carton Labeling...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ... Container Labels and Carton Labeling Design To Minimize Medication Errors; Availability AGENCY: Food and... Labels and Carton Labeling Design to Minimize Medication Errors.'' The draft guidance focuses on safety aspects of the container label and carton labeling design for prescription drug and biological products...

  15. Advanced Developments in Cyclic Polymers: Synthesis, Applications, and Perspectives.

    PubMed

    Zhu, Yinghuai; Hosmane, Narayan S

    2015-08-01

    Due to the topological effect, cyclic polymers demonstrate different and unique physical and biological properties in comparison with linear counterparts having the same molecular-weight range. With advanced synthetic and analytic technologies, cyclic polymers with different topologies, e.g. multicyclic polymers, have been reported and well characterized. For example, various cyclic DNA and related structures, such as cyclic duplexes, have been prepared conveniently by click chemistry. These types of DNA have increased resistance to enzymatic degradation and have high thermodynamic stability, and thus, have potential therapeutic applications. In addition, cyclic polymers have also been used to prepare organic-inorganic hybrids for applications in catalysis, e.g. catalyst supports. Due to developments in synthetic technology, highly pure cyclic polymers could now be produced in large scale. Therefore, we anticipate discovering more applications in the near future. Despite their promise, cyclic polymers are still less explored than linear polymers like polyolefins and polycarbonates, which are widely used in daily life. Some critical issues, including controlling the molecular weight and finding suitable applications, remain big challenges in the cyclic-polymer field. This review briefly summarizes the commonly used synthetic methodologies and focuses more on the attractive functional materials and their biological properties and potential applications.

  16. Advanced Developments in Cyclic Polymers: Synthesis, Applications, and Perspectives

    PubMed Central

    Zhu, Yinghuai; Hosmane, Narayan S

    2015-01-01

    Due to the topological effect, cyclic polymers demonstrate different and unique physical and biological properties in comparison with linear counterparts having the same molecular-weight range. With advanced synthetic and analytic technologies, cyclic polymers with different topologies, e.g. multicyclic polymers, have been reported and well characterized. For example, various cyclic DNA and related structures, such as cyclic duplexes, have been prepared conveniently by click chemistry. These types of DNA have increased resistance to enzymatic degradation and have high thermodynamic stability, and thus, have potential therapeutic applications. In addition, cyclic polymers have also been used to prepare organic–inorganic hybrids for applications in catalysis, e.g. catalyst supports. Due to developments in synthetic technology, highly pure cyclic polymers could now be produced in large scale. Therefore, we anticipate discovering more applications in the near future. Despite their promise, cyclic polymers are still less explored than linear polymers like polyolefins and polycarbonates, which are widely used in daily life. Some critical issues, including controlling the molecular weight and finding suitable applications, remain big challenges in the cyclic-polymer field. This review briefly summarizes the commonly used synthetic methodologies and focuses more on the attractive functional materials and their biological properties and potential applications. PMID:26478835

  17. Synthesis of Cyclic Guanidines via Pd-Catalyzed Alkene Carboamination

    PubMed Central

    Zavesky, Blane P.; Babij, Nicholas R.; Fritz, Jonathan A.

    2013-01-01

    A new approach to the synthesis of substituted 5-membered cyclic guanidines is described. Palladium-catalyzed alkene carboamination reactions between acyclic N-allyl guanidines and aryl or alkenyl halides provide these products in good yield. This method allows access to a number of different cyclic guanidine derivatives in only two steps from readily available allylic amines. PMID:24147839

  18. Evaluating cyclic fatigue of sealants during outdoor testing

    Treesearch

    R. Sam Williams; Steven Lacher; Corey Halpin; Christopher White

    2009-01-01

    A computer-controlled test apparatus (CCTA) and other instrumentation for subjecting sealant specimens to cyclic fatigue during outdoor exposure was developed. The CCTA enables us to use weather-induced conditions to cyclic fatigue specimens and to conduct controlled tests in-situ during the outdoor exposure. Thermally induced dimensional changes of an aluminum bar...

  19. Variation potential influence on photosynthetic cyclic electron flow in pea.

    PubMed

    Sukhov, Vladimir; Surova, Lyubov; Sherstneva, Oksana; Katicheva, Lyubov; Vodeneev, Vladimir

    2014-01-01

    Cyclic electron flow is an important component of the total photosynthetic electron flow and participates in adaptation to the action of stressors. Local leaf stimulation induces electrical signals, including variation potential (VP), which inactivate photosynthesis; however, their influence on cyclic electron flow has not been investigated. The aim of this study was to investigate VP's influence on cyclic electron flow in pea (Pisum sativum L.). VP was induced in pea seedling leaves by local heating and measured in an adjacent, undamaged leaf by extracellular electrodes. CO2 assimilation was measured using a portable gas exchange measuring system. Photosystem I and II parameters were investigated using a measuring system for simultaneous assessment of P700 oxidation and chlorophyll fluorescence. Heating-induced VP reduced CO2 assimilation and electron flow through photosystem II. In response, cyclic electron flow rapidly decreased and subsequently slowly increased. Slow increases in cyclic flow were caused by decreased electron flow through photosystem II, which was mainly connected with VP-induced photosynthetic dark stage inactivation. However, direct influence by VP on photosystem I also participated in activation of cyclic electron flow. Thus, VP, induced by local leaf-heating, activated cyclic electron flow in undamaged leaves. This response was similar to photosynthetic changes observed under the direct action of stressors. Possible mechanisms of VP's influence on cyclic flow were discussed.

  20. Lower Confidence Interval Bounds for Coherent Systems with Cyclic Components

    DTIC Science & Technology

    1990-09-01

    Three lower confidence interval estimation procedures for system reliability of coherent systems with cyclic components are developed and their...failure times and applied to yield a lower confidence interval procedures for the reliability of coherent systems with cyclic and continuously operating components.

  1. Variation potential influence on photosynthetic cyclic electron flow in pea

    PubMed Central

    Sukhov, Vladimir; Surova, Lyubov; Sherstneva, Oksana; Katicheva, Lyubov; Vodeneev, Vladimir

    2015-01-01

    Cyclic electron flow is an important component of the total photosynthetic electron flow and participates in adaptation to the action of stressors. Local leaf stimulation induces electrical signals, including variation potential (VP), which inactivate photosynthesis; however, their influence on cyclic electron flow has not been investigated. The aim of this study was to investigate VP's influence on cyclic electron flow in pea (Pisum sativum L.). VP was induced in pea seedling leaves by local heating and measured in an adjacent, undamaged leaf by extracellular electrodes. CO2 assimilation was measured using a portable gas exchange measuring system. Photosystem I and II parameters were investigated using a measuring system for simultaneous assessment of P700 oxidation and chlorophyll fluorescence. Heating-induced VP reduced CO2 assimilation and electron flow through photosystem II. In response, cyclic electron flow rapidly decreased and subsequently slowly increased. Slow increases in cyclic flow were caused by decreased electron flow through photosystem II, which was mainly connected with VP-induced photosynthetic dark stage inactivation. However, direct influence by VP on photosystem I also participated in activation of cyclic electron flow. Thus, VP, induced by local leaf-heating, activated cyclic electron flow in undamaged leaves. This response was similar to photosynthetic changes observed under the direct action of stressors. Possible mechanisms of VP's influence on cyclic flow were discussed. PMID:25610447

  2. MICROWAVE-ASSISTED PREPARATION OF CYCLIC UREAS FROM DIAMINES

    EPA Science Inventory

    Rajender S. Varma* and Yong-Jin Kim
    Cyclic ureas are useful intermediates for a variety of pharmaceuticals and pesticides. One of the attractive approaches for the synthesis of cyclic ureas uses condensation of diamines with urea as a carbonyl source under dynamic evacuation. ...

  3. MICROWAVE-ASSISTED PREPARATION OF CYCLIC UREAS FROM DIAMINES

    EPA Science Inventory

    Rajender S. Varma* and Yong-Jin Kim
    Cyclic ureas are useful intermediates for a variety of pharmaceuticals and pesticides. One of the attractive approaches for the synthesis of cyclic ureas uses condensation of diamines with urea as a carbonyl source under dynamic evacuation. ...

  4. Flexural creep of structural flakeboards under cyclic humidity

    Treesearch

    M.C. Yeh; R.C. Tang; Chung-Yun Hse

    1990-01-01

    Flexural creep behavior of randomly oriented structural flakeboards under cyclic humidity is presented. Specimens fabricated with 5 and 7 percent phenol-formaldehyde resin were subjected to constant concentrated load in bending under slow and fast cyclic relative humidity (RH) between 65 and 95 percent for 100 days. The temperature was set at a constant 75°F through...

  5. High-Temperature Cyclic Oxidation Data, Volume 1

    NASA Technical Reports Server (NTRS)

    Barrett, C. A.; Garlick, R. G.; Lowell, C. E.

    1984-01-01

    This first in a series of cyclic oxidation handbooks contains specific-weight-change-versus-time data and X-ray diffraction results derived from high-temperature cyclic tests on high-temperature, high-strength nickel-base gamma/gamma' and cobalt-base turbine alloys. Each page of data summarizes a complete test on a given alloy sample.

  6. Consecutive isocyanide-based multicomponent reactions: synthesis of cyclic pentadepsipeptoids

    PubMed Central

    Barreto, Angélica de Fátima S; Vercillo, Otilie E; Wessjohann, Ludger A

    2014-01-01

    Summary The synthesis of six cyclic depsipeptoids inspired by the natural depsipeptide sansalvamide A is described. An efficient and fast synthetic strategy was developed using a combination of consecutive isocyanide-based multicomponent reactions (Ugi and Passerini reactions). This methodology can be used to access a variety of cyclic oligodepsipeptoids. PMID:24991252

  7. New Methods for Labeling RGD Peptides with Bromine-76

    PubMed Central

    Lang, Lixin; Li, Weihua; Jia, Hong-Mei; Fang, De-Cai; Zhang, Shushu; Sun, Xilin; Zhu, Lei; Ma, Ying; Shen, Baozhong; Kiesewetter, Dale O.; Niu, Gang; Chen, Xiaoyuan

    2011-01-01

    Direct bromination of the tyrosine residues of peptides and antibodies with bromine-76, to create probes for PET imaging, has been reported. For peptides that do not contain tyrosine residues, however, a prosthetic group is required to achieve labeling via conjugation to other functional groups such as terminal α-amines or lysine ε-amines. The goal of this study was to develop new strategies for labeling small peptides with Br-76 using either a direct labeling method or a prosthetic group, depending on the available functional group on the peptides. A new labeling agent, N-succinimidyl-3-[76Br]bromo-2,6-dimethoxybenzoate ([76Br]SBDMB) was prepared for cyclic RGD peptide labeling. N-succinimidyl-2, 6-dimethoxybenzoate was also used to pre-attach a 2, 6-dimethoxybenzoyl (DMB) moiety to the peptide, which could then be labeled with Br-76. A competitive cell binding assay was performed to determine the binding affinity of the brominated peptides. PET imaging of U87MG human glioblastoma xenografted mice was performed using [76Br]-BrE[c(RGDyK)]2 and [76Br]-BrDMB-E[c(RGDyK)]2. An ex vivo biodistribution assay was performed to confirm PET quantification. The mechanisms of bromination reaction between DMB-c(RGDyK) and the brominating agent CH3COOBr were investigated with the SCRF-B3LYP/6-31G* method with the Gaussian 09 program package. The yield for direct labeling of c(RGDyK) and E[c(RGDyK)]2 using chloramine-T and peracetic acid at ambient temperature was greater than 50%. The yield for [76Br]SBDMB was over 60% using peracetic acid. The conjugation yields for labeling c(RGDfK) and c(RGDyK) were over 70% using the prosthetic group at room temperature. Labeling yield for pre-conjugated peptides was over 60%. SDMB conjugation and bromination did not affect the binding affinity of the peptides with integrin receptors. Both [76Br]Br-E[c(RGDyK)]2 and [76Br]BrDMB-E[c(RGDyK)]2 showed high tumor uptake in U87MG tumor bearing mice. The specificity of the imaging tracers was

  8. Approximation Algorithms for Free-Label Maximization

    NASA Astrophysics Data System (ADS)

    de Berg, Mark; Gerrits, Dirk H. P.

    Inspired by air traffic control and other applications where moving objects have to be labeled, we consider the following (static) point labeling problem: given a set P of n points in the plane and labels that are unit squares, place a label with each point in P in such a way that the number of free labels (labels not intersecting any other label) is maximized. We develop efficient constant-factor approximation algorithms for this problem, as well as PTASs, for various label-placement models.

  9. Normal ovarian surface epithelial label-retaining cells exhibit stem/progenitor cell characteristics.

    PubMed

    Szotek, Paul P; Chang, Henry L; Brennand, Kristen; Fujino, Akihiro; Pieretti-Vanmarcke, Rafael; Lo Celso, Cristina; Dombkowski, David; Preffer, Frederic; Cohen, Kenneth S; Teixeira, Jose; Donahoe, Patricia K

    2008-08-26

    Ovulation induces cyclic rupture and regenerative repair of the ovarian coelomic epithelium. This process of repeated disruption and repair accompanied by complex remodeling typifies a somatic stem/progenitor cell-mediated process. Using BrdU incorporation and doxycycline inducible histone2B-green fluorescent protein pulse-chase techniques, we identify a label-retaining cell population in the coelomic epithelium of the adult mouse ovary as candidate somatic stem/progenitor cells. The identified population exhibits quiescence with asymmetric label retention, functional response to estrous cycling in vivo by proliferation, enhanced growth characteristics by in vitro colony formation, and cytoprotective mechanisms by enrichment for the side population. Together, these characteristics identify the label-retaining cell population as a candidate for the putative somatic stem/progenitor cells of the coelomic epithelium of the mouse ovary.

  10. Normal ovarian surface epithelial label-retaining cells exhibit stem/progenitor cell characteristics

    PubMed Central

    Szotek, Paul P.; Chang, Henry L.; Brennand, Kristen; Fujino, Akihiro; Pieretti-Vanmarcke, Rafael; Lo Celso, Cristina; Dombkowski, David; Preffer, Frederic; Cohen, Kenneth S.; Teixeira, Jose; Donahoe, Patricia K.

    2008-01-01

    Ovulation induces cyclic rupture and regenerative repair of the ovarian coelomic epithelium. This process of repeated disruption and repair accompanied by complex remodeling typifies a somatic stem/progenitor cell-mediated process. Using BrdU incorporation and doxycycline inducible histone2B-green fluorescent protein pulse–chase techniques, we identify a label-retaining cell population in the coelomic epithelium of the adult mouse ovary as candidate somatic stem/progenitor cells. The identified population exhibits quiescence with asymmetric label retention, functional response to estrous cycling in vivo by proliferation, enhanced growth characteristics by in vitro colony formation, and cytoprotective mechanisms by enrichment for the side population. Together, these characteristics identify the label-retaining cell population as a candidate for the putative somatic stem/progenitor cells of the coelomic epithelium of the mouse ovary. PMID:18711140

  11. New Labeling for Neonicotinoid Pesticides

    EPA Pesticide Factsheets

    These documents, a graphic of the bee advisory box and letters to pesticide registrants, describe steps by EPA to change pesticide labels to better protect pollinators by being clearer and more precise in their directions for pesticide application.

  12. Locating the Vehicle Emissions Label

    EPA Pesticide Factsheets

    The EPA vehicle emissions label is entitled Vehicle Emission Control Information and contains the name and trademark of the manufacturer and an unconditional statement of compliance with EPA emission regulations.

  13. How to Read Drug Labels

    MedlinePlus

    ... Home > Healthy Aging > Drugs and alternative medicine Healthy Aging How to read drug labels Printer-friendly version ... html Connect with other organizations National Institute on Aging, NIH, HHS http://www.nia.nih.gov/ U.S. ...

  14. Meat and Poultry Labeling Terms

    MedlinePlus

    ... Food Safety and Inspection Service and the Agriculture Marketing Service have officially evaluated a meat product for ... refer to these factsheets from the USDA Agricultural Marketing Service: Organic Food Standards and Labels: The Facts ...

  15. "Off-Label" Drug Use

    MedlinePlus

    ... for a single ailment. This is simply the nature of both drug devel- opment and clinical medicine. ... off-label use of cancer drugs. Given the nature of cancer and cancer drugs, this approach sounds ...

  16. Relaxation labeling using modular operators

    SciTech Connect

    Duncan, J.S.; Frei, W.

    1983-01-01

    Probabilistic relaxation labeling has been shown to be useful in image processing, pattern recognition, and artificial intelligence. The approaches taken to date have been encumbered with computationally extensive summations which generally prevent real-time operation and/or easy hardware implementation. The authors present a new and unique approach to the relaxation labeling problem using modular, VLSI-oriented hierarchical complex operators. One of the fundamental concepts of this work is the representation of the probability distribution of the possible labels for a given object (pixel) as an ellipse, which may be summed with neighboring object's distribution ellipses, resulting in a new, relaxed label space. The mathematical development of the elliptical approach will be presented and compared to more classical approaches, and a hardware block diagram that shows the implementation of the relaxation scheme using vlsi chips will be presented. Finally, results will be shown which illustrate applications of the modular scheme, iteratively, to both edges and lines. 13 references.

  17. Label-Free Receptor Assays

    PubMed Central

    Fang, Ye

    2010-01-01

    Label-free biosensors offer integrated, kinetic and multi-parametric measures of receptor biology and ligand pharmacology in whole cells. Being highly sensitive and pathway-unbiased, label-free receptor assays can be used to probe the systems cell biology including pleiotropic signaling of receptors, and to characterize the functional selectivity and phenotypic pharmacology of ligand molecules. These assays provide a new dimension for elucidating receptor biology and for facilitating drug discovery. PMID:21221420

  18. Label-Free Receptor Assays.

    PubMed

    Fang, Ye

    2011-01-01

    Label-free biosensors offer integrated, kinetic and multi-parametric measures of receptor biology and ligand pharmacology in whole cells. Being highly sensitive and pathway-unbiased, label-free receptor assays can be used to probe the systems cell biology including pleiotropic signaling of receptors, and to characterize the functional selectivity and phenotypic pharmacology of ligand molecules. These assays provide a new dimension for elucidating receptor biology and for facilitating drug discovery.

  19. Electrothermal branding for embryo labeling.

    PubMed

    Wang, L; Beebe, D J; Williams, A R; Easley, K D

    1997-11-01

    A novel embryo labeling technique based on electrothermal branding is developed. Two types of micro branding irons are fabricated and tested. One utilizes 25 microns tungsten wire as the heating element. The other utilizes surface micromachining techniques to fabricate polysilicon branding irons. The thermal behavior of the branding irons and the heat distributions in the embryos are analytically modeled. Micron-scale labels on unfertilized bovine embryos are achieved.

  20. Radiation Effects on Cyclic AMP, Cyclic GMP, and Amino Acid Levels in the CSF of the Primate

    DTIC Science & Technology

    1980-11-07

    rradiation . An analysis of brain areas obtained by biopsy of irradiated animals showed significant decreases in only the cerebellar cyclic AMP and cyclic...GMP. No appreciablk ¢±anges were found in the CSF amino acid composition. Acc. !-,’r ror UV , . c" l. __ ..:j’od I7 .... ’U r~rd0 /or cpy I NCI

  1. Inter-rater reliability of cyclic and non-cyclic task assessment using the hand activity level in appliance manufacturing.

    PubMed

    Paulsen, Robert; Schwatka, Natalie; Gober, Jennifer; Gilkey, David; Anton, Dan; Gerr, Fred; Rosecrance, John

    2014-01-01

    This study evaluated the inter-rater reliability of the American Conference of Governmental Industrial Hygienists (ACGIH(®)) hand activity level (HAL), an observational ergonomic assessment method used to estimate physical exposure to repetitive exertions during task performance. Video recordings of 858 cyclic and non-cyclic appliance manufacturing tasks were assessed by sixteen pairs of raters using the HAL visual-analog scale. A weighted Pearson Product Moment-Correlation Coefficient was used to evaluate the agreement between the HAL scores recorded by each rater pair, and the mean weighted correlation coefficients for cyclic and non-cyclic tasks were calculated. Results indicated that the HAL is a reliable exposure assessment method for cyclic (r̄-bar w = 0.69) and non-cyclic work tasks (r̄-bar w = 0.68). When the two reliability scores were compared using a two-sample Student's t-test, no significant difference in reliability (p = 0.63) between these work task categories was found. This study demonstrated that the HAL may be a useful measure of exposure to repetitive exertions during cyclic and non-cyclic tasks.

  2. Cloning and Immunocytochemical Localization of a Cyclic Nucleotide–Gated Channel α-Subunit to All Cone Photoreceptors in the Mouse Retina

    PubMed Central

    HIRANO, ARLENE A.; HACK, IRIS; WÄSSLE, HEINZ; DUVOISIN, ROBERT M.

    2010-01-01

    Cyclic nucleotide–gated channels (CNGC) are ligand-gated ion channels that open and close in response to changes in the intracellular concentration of the second messengers, 3′,5′-cyclic adenosine monophosphate and 3′,5′-cyclic guanosine monophosphate. Most notably, they transduce the chemical signal produced by the absorption of light in photoreceptors into a membrane potential change, which is then transmitted to the ascending visual pathway. CNGCs have also been implicated in the signal transduction of other neurons downstream of the photoreceptors, in particular the ON-bipolar cells, as well as in other areas of the central nervous system. We therefore undertook a search for additional cyclic nucleotide–gated channels expressed in the retina. Following a degenerate reverse transcription polymerase chain reaction approach to amplify low-copy number messages, a cDNA encoding a new splice variant of CNGC α-subunit was isolated from mouse retina and classified as mCNG3. An antiserum raised against the carboxy-terminal sequence identified the retinal cell type expressing mCNG3 as cone photoreceptors. Preembedding immunoelectron microscopy demonstrated its membrane localization in the outer segments, consistent with its role in phototransduction. Double-labeling experiments with cone-specific markers indicated that all cone photoreceptors in the murid retina use the same or a highly conserved cyclic nucleotide–gated channel. Therefore, defects in this channel would be predicted to severely impair photopic vision. PMID:10813773

  3. Availability of Spanish prescription labels.

    PubMed

    Sharif, Iman; Lo, Sarah; Ozuah, Philip O

    2006-02-01

    The research team conducted a cross-sectional telephone survey of all pharmacies in the Bronx, New York (99.4% participation rate) to determine availability of Spanish prescription labels. One hundred twenty five pharmacies (78%) were small independent pharmacies; 36 (22%) were large-chain pharmacies. Overall, 111 (69%) stated that they could provide prescription labels in Spanish. Overall, for all the pharmacy ZIP codes, the mean proportion of the population that was Spanish-speaking was 46.8% (range 11% to 71.6%). Seventy-eight (48%) pharmacies were located in areas where more than 50% of the population were Spanish-speaking, 48 (30%) were located in areas with 25.1-50% Spanish-speakers, and 35 (22%) were in areas with up to 25% Spanish-speakers. Small independent pharmacies were more likely than large chain pharmacies to provide prescription labels in Spanish (71% vs. 61%, p=0.25). All the pharmacists commented that a patient must specifically request a Spanish prescription label in order to receive one. Pharmacies located in areas with the highest proportion of Spanish speakers were more likely to provide prescription labels in Spanish (82% vs. 62% vs. 49%; p=.001). Of the 111 pharmacies that could provide Spanish labels, 95 (86%) used a computer program to perform the translation and 16(14%) used a lay employee. Of pharmacies using a computer program, only one had a Spanish-speaking pharmacist who could check and correct the computer translations.

  4. The cyclical nature of depressed mood and future risk: Depression, rumination, and deficits in emotional clarity in adolescent girls.

    PubMed

    Rubenstein, Liza M; Hamilton, Jessica L; Stange, Jonathan P; Flynn, Megan; Abramson, Lyn Y; Alloy, Lauren B

    2015-07-01

    Deficits in emotional clarity, the understanding and awareness of one's own emotions and the ability to label them appropriately, are associated with increased depressive symptoms. Surprisingly, few studies have examined factors associated with reduction in emotional clarity for adolescents, such as depressed mood and ruminative response styles. The present study examined rumination as a potential mediator of the relationship between depressive symptoms and changes in emotional clarity, focusing on sex differences. Participants included 223 adolescents (51.60% female, Mean age = 12.39). Controlling for baseline levels of emotional clarity, initial depressive symptoms predicted decreases in emotional clarity. Further, rumination prospectively mediated the relationship between baseline depressive symptoms and follow-up emotional clarity for girls, but not boys. Findings suggest that depressive symptoms may increase girls' tendencies to engage in repetitive, negative thinking, which may reduce the ability to understand and label emotions, a potentially cyclical process that confers vulnerability to future depression.

  5. The cyclical nature of depressed mood and future risk: Depression, rumination, and deficits in emotional clarity in adolescent girls

    PubMed Central

    Rubenstein, Liza M.; Hamilton, Jessica L.; Stange, Jonathan P.; Flynn, Megan; Abramson, Lyn Y.; Alloy, Lauren B.

    2015-01-01

    Deficits in emotional clarity, the understanding and awareness of one’s own emotions and the ability to label them appropriately, are associated with increased depressive symptoms. Surprisingly, few studies have examined factors associated with reduction in emotional clarity for adolescents, such as depressed mood and ruminative response styles. The present study examined rumination as a potential mediator of the relationship between depressive symptoms and changes in emotional clarity, focusing on sex differences. Participants included 223 adolescents (51.60% female, Mean age = 12.39). Controlling for baseline levels of emotional clarity, initial depressive symptoms predicted decreases in emotional clarity. Further, rumination prospectively mediated the relationship between baseline depressive symptoms and follow-up emotional clarity for girls, but not boys. Findings suggest that depressive symptoms may increase girls’ tendencies to engage in repetitive, negative thinking, which may reduce the ability to understand and label emotions, a potentially cyclical process that confers vulnerability to future depression. PMID:25931160

  6. Cyclodepsipeptides produced by actinomycetes inhibit cyclic-peptide-mediated quorum sensing in Gram-positive bacteria.

    PubMed

    Desouky, Said E; Shojima, Akane; Singh, Ravindra Pal; Matsufuji, Takahisa; Igarashi, Yasuhiro; Suzuki, Takashi; Yamagaki, Tohru; Okubo, Ken-Ichi; Ohtani, Kaori; Sonomoto, Kenji; Nakayama, Jiro

    2015-07-01

    Cyclic peptides are commonly used as quorum-sensing autoinducers in Gram-positive Firmicutes bacteria. Well-studied examples of such molecules are thiolactone and lactone, used to regulate the expression of a series of virulence genes in the agr system of Staphylococcus aureus and the fsr system of Enterococcus faecalis, respectively. Three cyclodepsipeptides WS9326A, WS9326B and cochinmicin II/III were identified as a result of screening actinomycetes culture extracts for activity against the agr/fsr system. These molecules are already known as receptor antagonists, the first two for tachykinin and the last one for endothelin. WS9326A also inhibited the transcription of pfoA regulated by the VirSR two-component system in Clostridium perfringens. Receptor-binding assays using a fluorescence-labeled autoinducer (FITC-GBAP) showed that WS9326A and WS9326B act as receptor antagonists in this system. In addition, an ex vivo assay showed that WS9326B substantially attenuated the toxicity of S. aureus for human corneal epithelial cells. These results suggest that these three natural cyclodepsipeptides have therapeutic potential for targeting the cyclic peptide-mediated quorum sensing of Gram-positive pathogens. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Cyclic nucleotide specific phosphodiesterases of Leishmania major

    PubMed Central

    Johner, Andrea; Kunz, Stefan; Linder, Markus; Shakur, Yasmin; Seebeck, Thomas

    2006-01-01

    Background Leishmania represent a complex of important human pathogens that belong to the systematic order of the kinetoplastida. They are transmitted between their human and mammalian hosts by different bloodsucking sandfly vectors. In their hosts, the Leishmania undergo several differentiation steps, and their coordination and optimization crucially depend on numerous interactions between the parasites and the physiological environment presented by the fly and human hosts. Little is still known about the signalling networks involved in these functions. In an attempt to better understand the role of cyclic nucleotide signalling in Leishmania differentiation and host-parasite interaction, we here present an initial study on the cyclic nucleotide-specific phosphodiesterases of Leishmania major. Results This paper presents the identification of three class I cyclic-nucleotide-specific phosphodiesterases (PDEs) from L. major, PDEs whose catalytic domains exhibit considerable sequence conservation with, among other, all eleven human PDE families. In contrast to other protozoa such as Dictyostelium, or fungi such as Saccharomyces cerevisiae, Candida ssp or Neurospora, no genes for class II PDEs were found in the Leishmania genomes. LmjPDEA contains a class I catalytic domain at the C-terminus of the polypeptide, with no other discernible functional domains elsewhere. LmjPDEB1 and LmjPDEB2 are coded for by closely related, tandemly linked genes on chromosome 15. Both PDEs contain two GAF domains in their N-terminal region, and their almost identical catalytic domains are located at the C-terminus of the polypeptide. LmjPDEA, LmjPDEB1 and LmjPDEB2 were further characterized by functional complementation in a PDE-deficient S. cerevisiae strain. All three enzymes conferred complementation, demonstrating that all three can hydrolyze cAMP. Recombinant LmjPDEB1 and LmjPDEB2 were shown to be cAMP-specific, with Km values in the low micromolar range. Several PDE inhibitors were

  8. Indium-111 labeled monoclonal antibodies (Ab): The effect of DTPA conjugation on the Ab activity and tissue distribution

    SciTech Connect

    Sakahara, H.; Endo, K.; Nakashima, T.; Ohta, H.; Okada, K.; Yoshida, O.; Ohmomo, Y.; Horiuchi, K.; Yokoyama, A.; Torizuka, K.

    1984-01-01

    Monoclonal antibodies (Ab) to human ..cap alpha..-fetoprotein (AFP) were conjugated with diethylenetriaminepentaacetic acid (DTPA) using cyclic DTPA anhydride and the obtained conjugates, DTPA-Ab, were labeled with In-111. The effect of DTPA conjugation on the affinity constant and the maximum binding capacity of Ab was evaluated by radioimmunoassay and Scatchard plot analysis and In-111 labeled DTPA-Ab were used for the radioimmunodetection of tumor. Ab containing 1.0 DTPA molecule per Ab showed almost full retention of both the affinity constant and the maximum binding capacity. Then, 40 ..mu..Ci of In-111 labeled DTPA-Ab were injected intravenously to nude mice bearing AFP-producing human testicular tumor and the resulted were compared with I-131 labeled Ab. Scintigraphy clearly revealed transplanted tumor. Localization of In-111 labeled DTPA-Ab was significantly higher than I-131 labeled Ab. Tumor to blood ratio obtained at 4 days after injection was 2.59 with In-111 labeled DTPA-Ab compared to 0.99 with I-131 labeled Ab. When more than 1.9 DTPA molecules were incorporated per Ab, the maximum binding capacity decreased, although the affinity constant was less affected. These In-111 labeled DTPA-Ab caused significantly higher liver accumulation. These results indicate that In-111 labeled DTPA-Ab at a cojugated DTPA to Ab molar ratio of 1.0 may be superior to I-131 labeled Ab for tumor imaging, but the maximum binding capacity and tissue distribution of In-111 labeled DTPA-AB are greatly dependent upon the number of DTPA molecules incorporated per Ab molecule.

  9. On the Gray Image of Cyclic Codes over Finite Chain Rings

    NASA Astrophysics Data System (ADS)

    Qian, Jianfa; Ma, Wenping; Wang, Xinmei

    We introduce (1-γ)-cyclic code and cyclic codes over the finite chain ring R. We prove that the Gray image of a linear (1-γ)-cyclic code over R of length n is a distance invariant quasi-cyclic code over Fpk. We also prove that if (n, p)=1, then every code over Fpk which is the Gray image of a cyclic code over R of length n is equivalent to a quasi-cyclic code.

  10. Plasma adenosine 3',5'-cyclic monophosphate in human hypertension.

    PubMed

    Hamet, P; Kuchel, O; Fraysse, J; Genest, J

    1974-08-17

    In a previous study we observed an increase in urinary cyclic AMP in labile hypertension in the upright position and during isoproterenol infusion, in contrast to a decrease in control subjects. In the present study we measured the plasma level of cyclic AMP in control subjects and patients with various types of hypertension. We obtained the following results: (1) plasma cyclic AMP increases in response to upright posture in control subjects and hypertensive patients; (2) values of cyclic AMP in the recumbent and upright positions are comparable in control subjects and patients with essential hypertension, but are significantly higher in those with true renovascular hypertension due to bilateral renal artery stenosis; (3) propranolol inhibits the increase of plasma cyclic AMP in response to posture in control subjects, but has an opposite effect in labile hypertension where there is a further increase; (4) the rise in blood pressure in pheochromocytoma is associated with a considerable increase in plasma cyclic AMP.Present and previous data suggest that kidney handling of cyclic AMP is abnormal in hypertension, and that the specific defect may be related to the type of hypertension.

  11. Phorbol esters modulate cyclic AMP accumulation in porcine thyroid cells

    SciTech Connect

    Emoto, T.; Kasai, K.; Hiraiwa, M.; Shimoda, S.

    1988-01-01

    In cultured porcine thyroid cells, during 60 min incubation phorbol 12-myristate 13-acetate (PMA) had no effect on basal cyclic AMP accumulation and slightly stimulated cyclic AMP accumulation evoked by thyroid stimulating hormone (TSH) or forskolin. Cholera toxin-induced cyclic AMP accumulation was significantly stimulated by PMA. On the other hand, cyclic AMP accumulation evoked by prostaglandin E/sub 1/ or E/sub 2/ (PGE/sub 1/ and PGE/sub 2/) was markedly depressed by simultaneous addition of PMA. These opposing effects of PMA on cyclic AMP accumulation evoked by PGE and cholera toxin were observed in a dose-related fashion, with half-maximal effect of around 10/sup -9/ M in either case. The almost same effects of PMA on cyclic AMP accumulation in basal and stimulated conditions were also observed in freshly prepared thyroid cells. The present study was performed in the presence of phosphodiesterase inhibitor, 3-iso-butyl-1-methylxanthine (IBMX), indicating that PMA affected adenylate cyclase activity. Therefore, it is suggested that PMA may modulate the production of cyclic AMP in response to different stimuli, possibly by affecting several sites in the adenylate cyclase complex in thyroid cells.

  12. Reversible cyclic peptide libraries for the discovery of affinity ligands.

    PubMed

    Menegatti, Stefano; Ward, Kevin Lawrence; Naik, Amith Dattatray; Kish, William Stanley; Blackburn, Robert Kevin; Carbonell, Ruben Guillermo

    2013-10-01

    A novel strategy is presented for the identification of cyclic peptide ligands from combinatorial libraries of reversible cyclic depsipeptides. A method for the solid-phase synthesis of individual cyclic depsipeptides and combinatorial libraries of these compounds is proposed, which employs lactic acid (Lact) and the dipeptide ester (Nα-Ac)-Ser(Ala)- as linkers for dilactonization. Upon alkaline treatment of the beads selected by screening a model library, the cyclic depsipeptides are linearized and released from the solid support to the liquid phase, to be sequenced via single-step tandem mass spectrometry (MS/MS). The protocol presented for library synthesis provides for wide structural diversity. Two model sequences, VVWVVK and AAWAAR, were chosen to present different structural examples for depsipeptide libraries and demonstrate the process of sequence determination by mass spectrometry. Further, a case study using the IgG binding cyclic depsipeptide cyclo[(Nα-Ac)-S(A)-RWHYFK-Lact-E] is presented to demonstrate the process of library screening and sequence determination on the selected beads. Finally, a method is shown for synthesis of the irreversible cyclic peptide corresponding to the proposed depsipeptide structure, to make the ligand stable to the aqueous acid and alkaline conditions encountered in affinity chromatographic applications. The cyclic peptide ligand was synthesized on a poly(methacrylate) resin and used for chromatographic binding of the target IgG.

  13. Cyclic AMP-dependent protein kinase activity in Trypanosoma cruzi.

    PubMed Central

    Ulloa, R M; Mesri, E; Esteva, M; Torres, H N; Téllez-Iñón, M T

    1988-01-01

    A cyclic AMP-dependent protein kinase activity from epimastigote forms of Trypanosoma cruzi was characterized. Cytosolic extracts were chromatographed on DEAE-cellulose columns, giving two peaks of kinase activity, which were eluted at 0.15 M- and 0.32 M-NaCl respectively. The second activity peak was stimulated by nanomolar concentrations of cyclic AMP. In addition, a cyclic AMP-binding protein co-eluted with the second kinase activity peak. Cyclic AMP-dependent protein kinase activity was further purified by gel filtration, affinity chromatography on histone-agarose and cyclic AMP-agarose, as well as by chromatography on CM-Sephadex. The enzyme ('holoenzyme') could be partially dissociated into two different components: 'catalytic' and 'regulatory'. The 'regulatory' component had specific binding for cyclic AMP, and it inhibited phosphotransferase activity of the homologous 'catalytic component' or of the 'catalytic subunit' from bovine heart. Cyclic AMP reversed these inhibitions. A 'holoenzyme preparation' was phosphorylated in the absence of exogenous phosphate acceptor and analysed by polyacrylamide-gel electrophoresis. A 56 kDa band was phosphorylated. The same preparation was analysed by Western blotting, by using polyclonal antibodies to the regulatory subunits of protein kinases type I or II. Both antibodies reacted with the 56 kDa band. Images Fig. 7. Fig. 8. PMID:2848508

  14. Cyclic Vomiting Syndrome: An Update Illustrated by a Case Report

    PubMed Central

    Hermus, Ingeborg P. M.; Willems, Stacey J. B.; Bogman, Aimée C. C. F.; Janssen, Paddy K. C.; Brabers, Leonie; Schieveld, Jan N. M.

    2016-01-01

    Objective: This article presents an update on cyclic vomiting syndrome, a potentially exhausting disorder that can occur in children, adolescents, and adults and and has a huge impact on the quality of life. A structured literature search was conducted to explore the current knowledge about antipsychotics in the treatment of cyclic vomiting syndrome. A case report is presented of a 15-year-old boy with refractory cyclic vomiting syndrome (ICD-10 criteria), who finally responded to a unique combination of risperidone and amitriptyline. Data Sources: A literature search of English articles was performed in November 2015 using PubMed and the Cochrane Library with cyclic vomiting syndrome, cyclic vomiting, risperidone, and antipsychotics as key words. All types of publications were included. The publication period covered a span from 1976 to 2014. Study Selection and Data Extraction: In total, 13 articles were found. After screening the title and abstract, only 2 were selected. Results: In the current literature, only the use of chlorpromazine in the treatment of cyclic vomiting syndrome is mentioned. The possible underlying working mechanism of chlorpromazine is not clarified. Conclusions: Antipsychotics are hardly mentioned in the literature with regard to their antiemetic properties. Antipsychotics like risperidone, and its unique combination with amitriptyline, might be an important alternative to achieve a satisfactory treatment result in refractory cases of cyclic vomiting syndrome. PMID:27733950

  15. On-Chip Fluorescent Labeling using Reversed-phase Monoliths and Microchip Electrophoretic Separations of Selected Preterm Birth Biomarkers.

    PubMed

    Sonker, Mukul; Yang, Rui; Sahore, Vishal; Kumar, Suresh; Woolley, Adam T

    2016-11-21

    On-chip preconcentration, purification, and fluorescent labeling are desirable sample preparation steps to achieve complete automation in integrated microfluidic systems. In this work, we developed electrokinetically operated microfluidic devices for solid-phase extraction and fluorescent labeling of preterm birth (PTB) biomarkers. Reversed-phase monoliths based on different acrylate monomers were photopolymerized in cyclic olefin copolymer microdevices and studied for the selective retention and elution of a fluorescent dye and PTB biomarkers. Octyl methacrylate-based monoliths with desirable retention and elution characteristics were chosen and used for on-chip fluorescent labeling of three PTB biomarkers. Purification of on-chip labeled samples was done by selective elution of unreacted dye prior to sample. Automated and rapid on-chip fluorescent labeling was achieved with similar efficiency to that obtained for samples labeled off chip. Additionally, protocols for microchip electrophoresis of several off-chip-labeled PTB biomarkers were demonstrated in poly(methyl methacrylate) microfluidic devices. This study is an important step toward the development of integrated on-chip labeling and separation microfluidic devices for PTB biomarkers.

  16. Thermophoresis of cyclic oligosaccharides in polar solvents.

    PubMed

    Eguchi, Kazuya; Niether, Doreen; Wiegand, Simone; Kita, Rio

    2016-09-01

    Cyclodextrins are cyclic oligosaccharides which are interesting as drug delivery systems, because they can be used as containers for pharmaceutical substances. We studied the Ludwig-Soret effect of [Formula: see text]-, [Formula: see text]-, [Formula: see text]- and methyl-[Formula: see text]-cyclodextrin in water and formamide by infrared thermal diffusion forced Rayleigh scattering (IR-TDFRS). In water the Soret coefficient, S T, of [Formula: see text]-, [Formula: see text]- and [Formula: see text]-cyclodextrin increases with increasing temperature and shows a sign change from negative to positive around T = 35 (°) C, while S T of methyl-[Formula: see text]-cyclodextrin is positive in the entire investigated temperature. In formamide S T-values of all cyclodextrins coincide and show a slight decrease with temperature. We discuss the obtained results and relate the S T-values to the different hydrogen bonding capabilities of the cyclodextrins and the used solvents. It turns out that the change of S T with temperature correlates with the partition coefficient, logP, which indicates that more hydrophilic substances show a more pronounced temperature sensitivity of S T. Additionally we obtained a surprising result measuring the refractive index contrast factor with temperature, [Formula: see text] of cyclodextrins in formamide, which might be explained by a complex formation between cyclodextrins and formamide.

  17. Cyclic voltammetry of fast conducting electrocatalytic films.

    PubMed

    Costentin, Cyrille; Savéant, Jean-Michel

    2015-07-15

    In the framework of contemporary energy challenges, cyclic voltammetry is a particularly useful tool for deciphering the kinetics of catalytic films. The case of fast conducting films is analyzed, whether conduction is of the ohmic type or proceeds through rapid electron hopping. The rate-limiting factors are then the diffusion of the substrate in solution and through the film as well as the catalytic reaction itself. The dimensionless combination of the characteristics of these factors allows reducing the number of actual parameters to a maximum of two. The kinetics of the system may then be fully analyzed with the help of a kinetic zone diagram. Observing the variations of the current-potential responses with operational parameters such as film thickness, the potential scan rate and substrate concentration allows a precise assessment of the interplay between these factors and of the values of the rate controlling factors. A series of thought experiments is described in order to render the kinetic analysis more palpable.

  18. Cyclic Feedback Systems with Quorum Sensing Coupling.

    PubMed

    Gedeon, Tomas; Pernarowski, Mark; Wilander, Adam

    2016-06-01

    Synchronization and desynchronization is of great interest in the study of circadian rhythms, metabolic oscillations and time-dependent cell aggregate behaviors. Several recent studies examine synchronization and other dynamics in models of repressilators coupled by a quorum sensing mechanism that uses a diffusive signal. Their numerical simulations have shown the complexity of the collective behavior depends sensitively on which protein upregulates diffusive signal. In this paper, we rigorously prove that the collective dynamics indeed strongly depends on how the signaling network integrates into the repressilator network. In fact we prove a general result for a class of negative cyclic feedback systems with signaling of which the repressilator is but one example. We show that if the feedback along the signaling loop is also negative, the resulting negative feedback, negative signaling (Nf-Ns) system admits either unique stable equilibrium, or a stable oscillation. When a positive signaling feedback is included, the system is no longer (Nf-Ns) and numerically exhibits multistable dynamics (Ullner et al. in Phys Rev Lett 99:148103, 2007; Phys Rev E 78:031904, 2008). We demonstrate that this multistability emerges through saddle node bifurcations of a sole cubic curve-as in generic bistable models.

  19. Coarsening and biodiversity in cyclically competing species

    NASA Astrophysics Data System (ADS)

    Intoy, Ben; Pleimling, Michel

    2014-03-01

    When four species compete stochastically in a cyclic way, the formation of two teams of mutually neutral partners is observed. We study through numerical simulations the extinction processes that can take place in this system both in the well mixed case as well as on different types of lattices. The different routes to extinction are revealed by the probability distribution of the domination time, i.e. the time needed for one team to fully occupy the system. If swapping is allowed between neutral partners, then the probability distribution is dominated by very long-lived states where a few very large domains persist, each domain being occupied by a mix of individuals from species that form one of the teams. Many aspects of the possible extinction scenarios are lost when only considering averaged quantities as for example the mean domination time. We also discuss some results for a model where species, that compete in Rock-Paper-Scissor fashion, have mixed strategies rather than pure strategies. We compare the case with mixed strategy to the pure strategy case and look at similarities and differences. This work is supported by the US National Science Foundation through grant DMR-1205309.

  20. Cyclicity of some symmetric nilpotent centers

    NASA Astrophysics Data System (ADS)

    García, Isaac A.

    2016-03-01

    In this work we present techniques for bounding the cyclicity of a wide class of monodromic nilpotent singularities of symmetric polynomial planar vector fields. The starting point is identifying a broad family of nilpotent symmetric fields for which existence of a center is equivalent to existence of a local analytic first integral, which, unlike the degenerate case, is not true in general for nilpotent singularities. We are able to relate so-called ;focus quantities; to the ;Poincaré-Lyapunov quantities; arising from the Poincaré first return map. When we apply the method to concrete examples, we show in some cases that the upper bound is sharp. Our approach is based on computational algebra methods for determining a minimal basis (constructed by focus quantities instead of by Poincaré-Lyapunov quantities because of the easier computability of the former) of the associated polynomial Bautin ideal in the parameter space of the family. The case in which the Bautin ideal is not radical is also treated.

  1. Collagen network strengthening following cyclic tensile loading.

    PubMed

    Susilo, Monica E; Paten, Jeffrey A; Sander, Edward A; Nguyen, Thao D; Ruberti, Jeffrey W

    2016-02-06

    The bulk mechanical properties of tissues are highly tuned to the physiological loads they experience and reflect the hierarchical structure and mechanical properties of their constituent parts. A thorough understanding of the processes involved in tissue adaptation is required to develop multi-scale computational models of tissue remodelling. While extracellular matrix (ECM) remodelling is partly due to the changing cellular metabolic activity, there may also be mechanically directed changes in ECM nano/microscale organization which lead to mechanical tuning. The thermal and enzymatic stability of collagen, which is the principal load-bearing biopolymer in vertebrates, have been shown to be enhanced by force suggesting that collagen has an active role in ECM mechanical properties. Here, we ask how changes in the mechanical properties of a collagen-based material are reflected by alterations in the micro/nanoscale collagen network following cyclic loading. Surprisingly, we observed significantly higher tensile stiffness and ultimate tensile strength, roughly analogous to the effect of work hardening, in the absence of network realignment and alterations to the fibril area fraction. The data suggest that mechanical loading induces stabilizing changes internal to the fibrils themselves or in the fibril-fibril interactions. If such a cell-independent strengthening effect is operational in vivo, then it would be an important consideration in any multiscale computational approach to ECM growth and remodelling.

  2. Cyclic oxidation evaluation - Approaching application conditions.

    NASA Technical Reports Server (NTRS)

    Barrett, C. A.; Evans, E. B.

    1973-01-01

    Review of 1000 to 1200 C cyclic oxidation testing conducted on potential aircraft gas turbine Ni-, Co-, and Fe-base alloys. Furnace and burner rig testing are discussed, and the results are compared for selected alloys. The alloys fall into two groups, depending on their Cr and Al contents. One group forms mainly Cr2O3/chromite spinel scale(s), while the other forms alpha Al2O3/aluminate spinel scale(s). Spalling on thermal cycling leading to increased metal consumption is associated with the appearance of a chromite spinel. In the case of high-velocity burner rig tests this chromite forming tendency is reinforced by Cr2O3 vaporization depleting Cr in the alloy. In both types of tests, specific weight change is used as an indirect indicator of metal attack, since direct metal loss measurements require destructive analysis. An alternative nondestructive metal loss estimating parameter, based on a tentative mass balance gravimetric approach, shows some potential.

  3. Protein misfolding cyclic amplification of infectious prions

    PubMed Central

    Morales, Rodrigo; Duran-Aniotz, Claudia; Diaz-Espinoza, Rodrigo; Camacho, Manuel V; Soto, Claudio

    2014-01-01

    Prions are proteinaceous infectious agents responsible for the transmission of prion diseases. The lack of a procedure for cultivating prions in the laboratory has been a major limitation to the study of the unorthodox nature of this infectious agent and the molecular mechanism by which the normal prion protein (PrPC) is converted into the abnormal isoform (PrPSc). Protein misfolding cyclic amplification (PMCA ), described in detail in this protocol, is a simple, fast and efficient methodology to mimic prion replication in the test tube. PMCA involves incubating materials containing minute amounts of infectious prions with an excess of PrPC and boosting the conversion by cycles of sonication to fragment the converting units, thereby leading to accelerated prion replication. PMCA is able to detect the equivalent of a single molecule of infectious PrPSc and propagate prions that maintain high infectivity, strain properties and species specificity. A single PMCA assay takes little more than 3 d to replicate a large amount of prions, which could take years in an in vivo situation. Since its invention 10 years ago, PMCA has helped to answer fundamental questions about this intriguing infectious agent and has been broadly applied in research areas that include the food industry, blood bank safety and human and veterinary disease diagnosis. PMID:22743831

  4. A low-power arcjet cyclic lifetest

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Hardy, Terry L.; Haag, Thomas W.

    1987-01-01

    A cyclic lifetest of a low power dc arcjet thruster using a hydrogen/nitrogen propellant mixture simulating hydrazine is currently in progress. Over 300 hr of operation have been accumulated to date in 2 hr duty cycles at a power level of about 1.15 kW, approximating that available on commercial communications satellites. A burn-in period was carried out before consistent operation was attained. After this period, the arcjet operated in a very stable fashion from cycle to cycle. At the beginning of each cycle, there was a brief starting transient followed by a rapid rise to a steady-state voltage. The steady-state voltage increased by about 5 V over the first 95 cycles. After this, it increased by only 1 V through the remainder of the test. Thrust measurements taken before the life test and again after the completion of the 144th cycle showed that both thrust, specific impulse, and arc voltage had increased over this period of operation. No life limiting mechanisms were observed during the course of the testing.

  5. Copper Regulates Cyclic AMP-Dependent Lipolysis

    PubMed Central

    Krishnamoorthy, Lakshmi; Cotruvo, Joseph A.; Chan, Jefferson; Kaluarachchi, Harini; Muchenditsi, Abigael; Pendyala, Venkata S.; Jia, Shang; Aron, Allegra T.; Ackerman, Cheri M.; Vander Wal, Mark N.; Guan, Timothy; Smaga, Lukas P.; Farhi, Samouil L.; New, Elizabeth J.; Lutsenko, Svetlana; Chang, Christopher J.

    2016-01-01

    Cell signaling relies extensively on dynamic pools of redox-inactive metal ions such as sodium, potassium, calcium, and zinc, but their redox-active transition metal counterparts such as copper and iron have been studied primarily as static enzyme cofactors. Here we report that copper is an endogenous regulator of lipolysis, the breakdown of fat, which is an essential process in maintaining the body's weight and energy stores. Utilizing a murine model of genetic copper misregulation, in combination with pharmacological alterations in copper status and imaging studies in a 3T3-L1 white adipocyte model, we demonstrate that copper regulates lipolysis at the level of the second messenger, cyclic AMP (cAMP), by altering the activity of the cAMP-degrading phosphodiesterase PDE3B. Biochemical studies of the copper-PDE3B interaction establish copper-dependent inhibition of enzyme activity and identify a key conserved cysteine residue within a PDE3-specific loop that is essential for the observed copper-dependent lipolytic phenotype. PMID:27272565

  6. The cyclic fatigue behavior of adhesive joints

    NASA Astrophysics Data System (ADS)

    Kinloch, A. J.; Toh, T.

    1995-06-01

    In the last six months we have: (1) Concentrated our efforts on the fatigue failure of carbon-fiber PEEK/AFl63 lap joints, and in particular we have started to predict the life time of single-lap joints under cyclic fatigue loading. The analysis is based on data obtained from double cantilever beam (DCB) fracture mechanics tests; (2) Further, we have been successful in measuring the rate of crack growth in lap joints during fatigue fracture using ultrasonic scanning; (3) Preliminary test data on the static fracture of glass-fiber reinforced poly(phenylene sulphide) (PPS)/AF163 joints have also been studied; and (4) A comparison has been made in computing the critical strain energy release rate G(sub c) for the glass-fiber PPS/AF163 joints based on the compliance method, beam theory and corrected beam theory. The last method accounts for large non-linear deflections and the associated crack root rotations along with the necessary corrections for the increase in stiffness introduced by the presence of end blocks.

  7. Cyclic Amplification of Prion Protein Misfolding

    PubMed Central

    Barria, Marcelo A; Gonzalez-Romero, Dennisse; Soto, Claudio

    2014-01-01

    Protein Misfolfing Cyclic amplification (PMCA) is a technique that take advantage of the nucleation-dependent prion replication process to accelerate the conversion of PrPC into PrPSc in the test tube. PMCA uses ultrasound waves to fragment the PrPSc polymers, increasing the amount of seeds present in the infected sample without affecting their ability to act as conversion nucleus. Over the past 5 years PMCA has became an invaluable technique to study diverse aspects of prions. The PMCA technology has been used by several groups to understand the molecular mechanism of prion replication, the cellular factors involved in prion propagation, the intriguing phenomena of prion strains and species barriers, to detect PrPSc in tissues and biological fluids and to screen for inhibitors against prion replication. In this article we describe a detailed protocol of the PMCA technique, highlighting some of the important technical aspects to obtain a successful and reproducible application of the technology. PMID:22528092

  8. Pulsed cyclic laser based on dissociative excitation

    SciTech Connect

    Celto, J.E.; Schimitschek, E.J.

    1980-10-14

    A pulsed laser produces emitted laser energy by dissociative excitation of metal dihalide and cyclic recombination. A metal dihalide selected from subgroup ii-b of the periodic table of elements is contained within an elongate sealed enclosure. Two elongate electrodes having external terminals are supported in parallel relationship within the enclosure, forming a gap parallel to the principal axis of the enclosure. A source of pulsed electric power is connected to the terminals of the two electrodes, producing repetitive transverse electric discharges across the gap. An inert buffer gas is included within the enclosure for aiding electric discharge uniformity, and to provide vibrational relaxation of the lasing medium in its electronic states. The buffer gas is ionized by a third electrode within the enclosure connected to a source of pulses which immediately precede the pulses applied to the first and second electrode so that the lasing medium is preionized immediately prior to the principal electric discharge. Two reflective surfaces, one of which is only partially reflective, are aligned with the principal axis of the laser assembly for producing an optical resonator for the emitted laser energy.

  9. Cyclic flow underground coal gasification process

    DOEpatents

    Bissett, Larry A.

    1978-01-01

    The present invention is directed to a method of in situ coal gasification for providing the product gas with an enriched concentration of carbon monoxide. The method is practiced by establishing a pair of combustion zones in spaced-apart boreholes within a subterranean coal bed and then cyclically terminating the combustion in the first of the two zones to establish a forward burn in the coal bed so that while an exothermic reaction is occurring in the second combustion zone to provide CO.sub.2 -laden product gas, an endothermic CO-forming reaction is occurring in the first combustion zone between the CO.sub.2 -laden gas percolating thereinto and the hot carbon in the wall defining the first combustion zone to increase the concentration of CO in the product gas. When the endothermic reaction slows to a selected activity the roles of the combustion zones are reversed by re-establishing an exothermic combustion reaction in the first zone and terminating the combustion in the second zone.

  10. Cyclical vomiting syndrome: Recognition, assessment and management.

    PubMed

    Tan, Michelle Ln; Liwanag, Maria Janelle; Quak, Seng Hock

    2014-08-08

    Cyclical vomiting syndrome (CVS) is a functional, debilitating disorder of childhood frequently leading to hospitalization. Affected children usually experience a stereotypical pattern of vomiting though it may vary between different individuals. The vomiting is intense often bilious, and accompanied by disabling nausea. Identifiable precipitating factors for CVS include psychosocial stressors, infections, lack of sleep and occasionally even food triggers. Often, it may be difficult to distinguish episodes of CVS from other causes of acute abdomen and altered consciousness. Thus, the diagnosis of CVS remains largely one of exclusion. Investigations routinely done during the work-up of a child with suspected CVS include both blood and imaging modalities. Plasma lactate, ammonia, amino acid and acylcarnitine profiles as well as urine organic acid profile are indicated to exclude inborn errors of metabolism. The treatment remains challenging and targeted at prevention or shortening of the attacks and can be considered as abortive, supportive and prophylactic. Use of non-pharmacological therapy is also part of the management of CVS. The prognosis of CVS is variable. More insight into the pathogenesis of this disorder as well as role of non-pharmacological therapy is needed.

  11. Cyclic Vomiting Syndrome: A Functional Disorder

    PubMed Central

    Kaul, Kanwar K.

    2015-01-01

    Cyclic vomiting syndrome (CVS) is a functional disorder characterized by stereotypical episodes of intense vomiting separated by weeks to months. Although it can occur at any age, the most common age at presentation is 3-7 years. There is no gender predominance. The precise pathophysiology of CVS is not known but a strong association with migraine headaches, in the patient as well as the mother indicates that it may represent a mitochondriopathy. Studies have also suggested the role of an underlying autonomic neuropathy involving the sympathetic nervous system in its pathogenesis. CVS has known triggers in many individuals and avoiding these triggers can help prevent the onset of the episodes. It typically presents in four phases: a prodrome, vomiting phase, recovery phase and an asymptomatic phase until the next episode. Complications such as dehydration and hematemesis from Mallory Wise tear of the esophageal mucosa may occur in more severe cases. Blood and urine tests and abdominal imaging may be indicated depending upon the severity of symptoms. Brain magnetic resonance imaging and upper gastrointestinal endoscopy may also be indicated in certain circumstances. Management of an episode after it has started ('abortive treatment') includes keeping the patient in a dark and quiet room, intravenous hydration, ondansetron, sumatriptan, clonidine, and benzodiazepines. Prophylactic treatment includes cyproheptadine, propranolol and amitriptyline. No mortality has been reported as a direct result of CVS and many children outgrow it over time. A subset may develop other functional disorders like irritable bowel syndrome and migraine headaches. PMID:26770896

  12. Cyclic mechanical preconditioning improves engineered muscle contraction.

    PubMed

    Moon, Du Geon; Christ, George; Stitzel, Joel D; Atala, Anthony; Yoo, James J

    2008-04-01

    The inability to engineer clinically relevant functional muscle tissue remains a major hurdle to successful skeletal muscle reconstructive procedures. This article describes an in vitro preconditioning protocol that improves the contractility of engineered skeletal muscle after implantation in vivo. Primary human muscle precursor cells (MPCs) were seeded onto collagen-based acellular tissue scaffolds and subjected to cyclic strain in a computer-controlled bioreactor system. Control constructs (static culture conditions) were run in parallel. Bioreactor preconditioning produced viable muscle tissue constructs with unidirectional orientation within 5 days, and in vitro-engineered constructs were capable of generating contractile responses after 3 weeks of bioreactor preconditioning. MPC-seeded constructs preconditioned in the bioreactor for 1 week were also implanted onto the latissimus dorsi muscle of athymic mice. Analysis of tissue constructs retrieved 1 to 4 weeks postimplantation showed that bioreactor-preconditioned constructs, but not statically cultured control tissues, generated tetanic and twitch contractile responses with a specific force of 1% and 10%, respectively, of that observed on native latissimus dorsi. To our knowledge, this is the largest force generated for tissue-engineered skeletal muscle on an acellular scaffold. This finding has important implications to the application of tissue engineering and regenerative medicine to skeletal muscle replacement and reconstruction.

  13. Beyond Inflation: A Cyclic Universe Scenario

    NASA Astrophysics Data System (ADS)

    Turok, Neil; Steinhardt, Paul J.

    2005-01-01

    Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful `cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both high energy and low energy inflation, with energy densities differing by a hundred orders of magnitude. The questions of why the universe started out undergoing high energy inflation, and why it will end up in low energy inflation, are unanswered. Rather than resort to anthropic arguments, we have developed an alternative cosmology, the cyclic universe, in which the universe exists in a very long-lived attractor state determined by the laws of physics. The model shares inflation's phenomenological successes without requiring an epoch of high energy inflation. Instead, the universe is made homogeneous and flat, and scale-invariant adiabatic perturbations are generated during an epoch of low energy acceleration like that seen today, but preceding the last big bang. Unlike inflation, the model requires low energy acceleration in order for a periodic attractor state to exist. The key challenge facing the scenario is that of passing through the cosmic singularity at t = 0. Substantial progress has been made at the level of linearised gravity, which is reviewed here. The challenge of extending this to nonlinear gravity and string theory remains.

  14. Beyond Inflation:. A Cyclic Universe Scenario

    NASA Astrophysics Data System (ADS)

    Turok, Neil; Steinhardt, Paul J.

    2005-08-01

    Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful 'cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both high energy and low energy inflation, with energy densities differing by a hundred orders of magnitude. The questions of why the universe started out undergoing high energy inflation, and why it will end up in low energy inflation, are unanswered. Rather than resort to anthropic arguments, we have developed an alternative cosmology, the cyclic universe [1], in which the universe exists in a very long-lived attractor state determined by the laws of physics. The model shares inflation's phenomenological successes without requiring an epoch of high energy inflation. Instead, the universe is made homogeneous and flat, and scale-invariant adiabatic perturbations are generated during an epoch of low energy acceleration like that seen today, but preceding the last big bang. Unlike inflation, the model requires low energy acceleration in order for a periodic attractor state to exist. The key challenge facing the scenario is that of passing through the cosmic singularity at t = 0. Substantial progress has been made at the level of linearised gravity, which is reviewed here. The challenge of extending this to nonlinear gravity and string theory remains.

  15. Interuniversal entanglement in a cyclic multiverse

    NASA Astrophysics Data System (ADS)

    Robles-Pérez, Salvador; Balcerzak, Adam; Dąbrowski, Mariusz P.; Krämer, Manuel

    2017-04-01

    We study scenarios of parallel cyclic multiverses which allow for a different evolution of the physical constants, while having the same geometry. These universes are classically disconnected, but quantum-mechanically entangled. Applying the thermodynamics of entanglement, we calculate the temperature and the entropy of entanglement. It emerges that the entropy of entanglement is large at big bang and big crunch singularities of the parallel universes as well as at the maxima of the expansion of these universes. The latter seems to confirm earlier studies that quantum effects are strong at turning points of the evolution of the universe performed in the context of the timeless nature of the Wheeler-DeWitt equation and decoherence. On the other hand, the entropy of entanglement at big rip singularities is going to zero despite its presumably quantum nature. This may be an effect of total dissociation of the universe structures into infinitely separated patches violating the null energy condition. However, the temperature of entanglement is large/infinite at every classically singular point and at maximum expansion and seems to be a better measure of quantumness.

  16. 40 CFR 211.104 - Label content.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Label content. 211.104 Section 211.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRODUCT NOISE LABELING General Provisions § 211.104 Label content. The following data and information must be on the label of all products for...

  17. 40 CFR 211.104 - Label content.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Label content. 211.104 Section 211.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRODUCT NOISE LABELING General Provisions § 211.104 Label content. The following data and information must be on the label of all products for...

  18. 40 CFR 211.104 - Label content.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Label content. 211.104 Section 211.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRODUCT NOISE LABELING General Provisions § 211.104 Label content. The following data and information must be on the label of all products for...

  19. 40 CFR 211.104 - Label content.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Label content. 211.104 Section 211.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRODUCT NOISE LABELING General Provisions § 211.104 Label content. The following data and information must be on the label of all products for...

  20. 40 CFR 211.104 - Label content.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Label content. 211.104 Section 211.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRODUCT NOISE LABELING General Provisions § 211.104 Label content. The following data and information must be on the label of all products for...

  1. 7 CFR 70.45 - Misleading labeling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Misleading labeling. 70.45 Section 70.45 Agriculture... Misleading labeling. The use of the terms “Government Graded” and “Federal-State Graded” or terms of similar import in the labeling or advertising of any product without stating in the labeling or advertisement the...

  2. 21 CFR 225.180 - Labeling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Labeling. 225.180 Section 225.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS Labeling § 225.180 Labeling. Labels shall...

  3. 21 CFR 225.180 - Labeling.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Labeling. 225.180 Section 225.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS Labeling § 225.180 Labeling. Labels shall...

  4. 21 CFR 225.180 - Labeling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Labeling. 225.180 Section 225.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS Labeling § 225.180 Labeling. Labels shall...

  5. 21 CFR 225.180 - Labeling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Labeling. 225.180 Section 225.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS Labeling § 225.180 Labeling. Labels shall...

  6. 21 CFR 225.180 - Labeling.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Labeling. 225.180 Section 225.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS Labeling § 225.180 Labeling. Labels shall...

  7. 78 FR 2200 - Energy Labeling Rule

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-10

    ... CFR Part 305 RIN 3084-AB15 Energy Labeling Rule AGENCY: Federal Trade Commission (FTC or Commission..., clarifying testing requirements and enforcement provisions, improving online energy label disclosures, and.... Appliance Labeling Rule The Commission issued the Appliance Labeling Rule pursuant to the Energy Policy...

  8. How to Read a Nutrition Facts Label

    MedlinePlus

    ... Games, and the Internet How to Read a Nutrition Facts Label (Video) KidsHealth > For Parents > How to Read a Nutrition Facts Label (Video) Print A A A en ... nutricionales (video) Most packaged foods come with a Nutrition Facts label. These labels have a lot of ...

  9. 40 CFR 211.108 - Sample label.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Sample label. 211.108 Section 211.108 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRODUCT NOISE LABELING General Provisions § 211.108 Sample label. Examples of labels conforming to the requirements...

  10. 21 CFR 610.60 - Container label.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Container label. 610.60 Section 610.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS GENERAL BIOLOGICAL PRODUCTS STANDARDS Labeling Standards § 610.60 Container label. (a) Full label. The...

  11. On quantum codes obtained from cyclic codes over A2

    NASA Astrophysics Data System (ADS)

    Dertli, Abdullah; Cengellenmis, Yasemin; Eren, Senol

    2015-05-01

    In this paper, quantum codes from cyclic codes over A2 = F2 + uF2 + vF2 + uvF2, u2 = u, v2 = v, uv = vu, for arbitrary length n have been constructed. It is shown that if C is self orthogonal over A2, then so is Ψ(C), where Ψ is a Gray map. A necessary and sufficient condition for cyclic codes over A2 that contains its dual has also been given. Finally, the parameters of quantum error correcting codes are obtained from cyclic codes over A2.

  12. Comparing linear and cyclic synthetic homopolypeptides: Synthesis and molecular characterization

    SciTech Connect

    Politakos, Nikolaos; Liontos, George; Kortaberria, Galder; Messman, Jamie M.; Calvo, Javier; Moya, Sergio E.; Mays, Jimmy W.; Avgeropoulos, Apostolos

    2014-10-24

    We report the synthesis and molecular characterization of a linear and a cyclic homopolypeptide of protected l-tyrosine. The successful synthesis of polypeptides exhibiting the desired linear and cyclic structures through various characterization methods such as high temperature gel permeation chromatography, Fourier transform infrared spectroscopy, proton and carbon nuclear magnetic resonance spectroscopy, mass spectrometry, dynamic light scattering, differential scanning calorimetry, and thermogravimetric analysis was verified in this work. Our results are very promising especially if such cyclic materials will be potentially used as carriers for drug delivery, either through conjugation with specific ligands or directly through the functional hydroxyl groups of the monomeric units of poly(l-Tyr) after deprotection.

  13. Cross-Correlation of Uniform Cyclic Difference Set Sequences.

    DTIC Science & Technology

    1987-06-01

    Mersenne prime (b) (i) and (iii) overlap iff v = 31 or 127 or 131071 (c) (i) and (iv) overlap iff v = 15. Some Hadamard type cyclic difference sets...cyclic shift of D. If q is an integer, relatively prime to v, then the set D** formed by multiplying every element of D by q, modulo v, as follows D...equivalent if Dk = qDj+z, modulo v, for some integers q and z with q relatively prime to v [Ref. l:pp. 1-2]. If D is a cyclic (v,k, A )-difference set

  14. Cyclic plasticity models and application in fatigue analysis

    NASA Technical Reports Server (NTRS)

    Kalev, I.

    1981-01-01

    An analytical procedure for prediction of the cyclic plasticity effects on both the structural fatigue life to crack initiation and the rate of crack growth is presented. The crack initiation criterion is based on the Coffin-Manson formulae extended for multiaxial stress state and for inclusion of the mean stress effect. This criterion is also applied for the accumulated damage ahead of the existing crack tip which is assumed to be related to the crack growth rate. Three cyclic plasticity models, based on the concept of combination of several yield surfaces, are employed for computing the crack growth rate of a crack plane stress panel under several cyclic loading conditions.

  15. The mycotoxin definition reconsidered towards fungal cyclic depsipeptides.

    PubMed

    Taevernier, Lien; Wynendaele, Evelien; De Vreese, Leen; Burvenich, Christian; De Spiegeleer, Bart

    2016-04-02

    Currently, next to the major classes, cyclic depsipeptides beauvericin and enniatins are also positioned as mycotoxins. However, as there are hundreds more fungal cyclic depsipeptides already identified, should these not be considered as mycotoxins as well? The current status of the mycotoxin definition revealed a lack of consistency, leading to confusion about what compounds should be called mycotoxins. Because this is of pivotal importance in risk assessment prioritization, a clear and quantitatively expressed mycotoxin definition is proposed, based on data of widely accepted mycotoxins. Finally, this definition is applied to a set of fungal cyclic depsipeptides, revealing that some of these should indeed be considered as mycotoxins.

  16. Influence of cyclic torsional preloading on cyclic fatigue resistance of nickel - titanium instruments.

    PubMed

    Pedullà, E; Lo Savio, F; Boninelli, S; Plotino, G; Grande, N M; Rapisarda, E; La Rosa, G

    2015-11-01

    To evaluate the effect of different torsional preloads on cyclic fatigue resistance of endodontic rotary instruments constructed from conventional nickel-titanium (NiTi), M-Wire or CM-Wire. Eighty new size 25, 0.06 taper Mtwo instruments (Sweden & Martina), size 25, 0.06 taper HyFlex CM (Coltene/Whaledent, Inc) and X2 ProTaper Next (Dentsply Maillefer) were used. The Torque and distortion angles at failure of new instruments (n = 10) were measured, and 0% (n = 10), 25%, 50% and 75% (n = 20) of the mean ultimate torsional strength as preloading condition were applied according to ISO 3630-1 for each brand. The twenty files tested for every extent of preload were subjected to 20 or 40 torsional cycles (n = 10). After torsional preloading, the number of cycles to failure was evaluated in a simulated canal with 60° angle of curvature and 5 mm of radius of curvature. Data were analysed using two-way analysis of variance. The fracture surface of each fragment was examined with a scanning electron microscope (SEM). Data were analysed by two-way analyses of variance. Preload repetitions did not influence the cyclic fatigue of the three brands; however, the 25%, 50% and 75% torsional preloading significantly reduced the fatigue resistance of all instruments tested (P < 0.01, P < 0.001 and P < 0.0001, respectively) except for the HyFlex CM preloaded with 25% of the maximum torsional strength (P > 0.05). Torsional preloads reduced the cyclic fatigue resistance of conventional and treated (M-wire and CM-wire) NiTi rotary instruments except for size 25, 0.06 taper HyFlex CM instruments with a 25% of torsional preloading. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  17. Investigation of Carbohydrate Metabolism and Transport in Castor Bean Seedlings by Cyclic JCross Polarization Imaging and Spectroscopy

    NASA Astrophysics Data System (ADS)

    Heidenreich, M.; Köckenberger, W.; Kimmich, R.; Chandrakumar, N.; Bowtell, R.

    1998-05-01

    NMR experiments using13C-labeled compounds offer the possibility of noninvasive monitoring of carbohydrate transport and metabolism in living plants, but are usually hampered by the low sensitivity of the13C nucleus. The problem of low sensitivity can be overcome by using the cyclicJcross polarization (CYCLCROP) technique, which allows the indirect detection of13C nuclei coupled to1H nuclei with the high NMR sensitivity of protons. We report here on methods for imaging and spectroscopy based on the CYCLCROP technique, and their use in the firstin vivoNMR study of carbohydrate transport and metabolism in castor bean seedlings (Ricinus communis L.). Comprehensive acquisition strategies for the various NMR methods are given, including the procedure for setting up the experiments. In addition, a full analysis of the effect of relaxation on the signals generated from smallJ-coupled spin systems by the CYCLCROP sequence is given, and the high sensitivity of the sequence is demonstrated. In thein vivostudy of six-day-old castor bean seedlings, we were able to measure the uptake of labeled hexoses, supplied in solution to the cotyledons, and their conversion to sucrose, as well as the transport of this sucrose in the vascular bundles. Images of the actual distribution of labeled sucrose in the hypocotyl of the seedling have also been obtained. The resulting data show some evidence for a preferential incorporation of labeled fructose in the process of sucrose synthesis, which decreases with the time of incubation.

  18. Mutant analysis suggests that cyclic GMP mediates the cyclic AMP-induced Ca2+ uptake in Dictyostelium.

    PubMed

    Menz, S; Bumann, J; Jaworski, E; Malchow, D

    1991-05-01

    Previous work has shown that streamer F (stmF) mutants of Dictyostelium discoideum exhibit prolonged chemotactic elongation in aggregation fields. The mutants carry an altered structural gene for cyclic GMP phosphodiesterase resulting in low activities of this enzyme. Chemotactic stimulation by cyclic AMP causes a rapid transient increase in the cyclic GMP concentration followed by association of myosin heavy chains with the cytoskeleton. Both events persist several times longer in stmF mutants than in the parental strain, indicating that the change in association of myosin with the cytoskeleton is transmitted directly or indirectly by cyclic GMP. We measured the cyclic AMP-induced Ca2+ uptake with a Ca(2+)-sensitive electrode and found that Ca2+ uptake was prolonged in stmF mutants but not in the parental strain. The G alpha 2 mutant strain HC33 (fgdA), devoid of InsP3 release and receptor/guanylate cyclase coupling, lacked Ca2+ uptake. However, the latter response and cyclic GMP formation were normal in the signal-relay mutant strain agip 53 where cyclic AMP-stimulated cyclic AMP synthesis is absent. LiCl, which inhibits InsP3 formation in Dictyostelium, blocked Ca2+ uptake in a dose-dependent manner. The data indicate that the receptor-mediated Ca2+ uptake depends on the InsP3 pathway and is regulated by cyclic GMP. The rate of Ca2+ uptake was correlated in time with the association of myosin with the cytoskeleton, suggesting that Ca2+ uptake is involved in the motility response of the cells.

  19. 75 FR 41696 - Appliance Labeling Rule

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-19

    ...Section 321 of the Energy Independence and Security Act of 2007 requires the Commission to consider the effectiveness of current labeling requirements for lamps (commonly referred to as light bulbs) and alternative labeling approaches. After holding a public meeting, conducting consumer research, issuing proposed changes to existing labeling requirements, and reviewing public comments, the Commission announces final amendments to the lamp labeling requirements in the Appliance Labeling Rule. The Commission also seeks further comment on several issues for consideration in any subsequent rulemaking.

  20. Nutrition Labeling Using a Computer Program

    NASA Astrophysics Data System (ADS)

    Metzger, Lloyd E.

    The 1990 Nutrition Labeling and Education Act mandated nutritional labeling of most foods. As a result, a large portion of food analysis is performed for nutritional labeling purposes. A food labeling guide and links to the complete nutritional labeling regulations are available online at http://vm.cfsan.fda.gov/˜dms/flg-toc.html. However, interpretation of these regulations and the appropriate usage of rounding rules, available nutrient content claims, reference amounts, and serving size can be difficult.

  1. 49 CFR 172.430 - POISON label.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false POISON label. 172.430 Section 172.430... SECURITY PLANS Labeling § 172.430 POISON label. (a) Except for size and color, the POISON label must be as follows: EC02MR91.029 (b) In addition to complying with § 172.407, the background on the POISON label...

  2. 49 CFR 172.430 - POISON label.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false POISON label. 172.430 Section 172.430... SECURITY PLANS Labeling § 172.430 POISON label. (a) Except for size and color, the POISON label must be as follows: EC02MR91.029 (b) In addition to complying with § 172.407, the background on the POISON label...

  3. 49 CFR 172.430 - POISON label.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false POISON label. 172.430 Section 172.430... SECURITY PLANS Labeling § 172.430 POISON label. (a) Except for size and color, the POISON label must be as follows: EC02MR91.029 (b) In addition to complying with § 172.407, the background on the POISON label...

  4. 49 CFR 172.430 - POISON label.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false POISON label. 172.430 Section 172.430... SECURITY PLANS Labeling § 172.430 POISON label. (a) Except for size and color, the POISON label must be as follows: EC02MR91.029 (b) In addition to complying with § 172.407, the background on the POISON label...

  5. 49 CFR 172.430 - POISON label.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false POISON label. 172.430 Section 172.430... SECURITY PLANS Labeling § 172.430 POISON label. (a) Except for size and color, the POISON label must be as follows: EC02MR91.029 (b) In addition to complying with § 172.407, the background on the POISON label...

  6. Induction of lutropin receptors by lutropin and cyclic AMP in cultured mouse tumour (MA10) Leydig cells.

    PubMed Central

    West, A P; Rose, M P; Cooke, B A

    1990-01-01

    The role of cyclic AMP in the regulation of lutropin (luteinizing hormone, LH) receptors has been investigated in cultured mouse tumour (MA10) Leydig cells. The LH receptors were quantified by measuring the binding of 125I-labelled human chorionic gonadotropin (hCG). LH (0.03 nM) in the presence of 1 mM-dibutyryl-cyclic AMP [(Bu)2cAMP] caused a 3-8-fold increase in subsequent 125I-hCG binding. (Bu)2cAMP (1 mM), cholera toxin (11.9 nM) and forskolin (1 microM) each caused a 2-4-fold increase in binding. In the presence of translation (cycloheximide) and transcription (actinomycin D) inhibitors, there was a loss of detectable binding sites. (Bu)2cAMP increased the rate of recovery of binding sites after trypsin treatment of MA10 cells, with a concomitant 2-fold increase in the level of binding sites. Under conditions where receptor levels were increased by 3-8-fold there was also a significant increase in pregnenolone production. It is concluded that LH and cyclic AMP have positive regulatory effects on LH receptors in MA10 cells by inducing the synthesis of new receptors. These induced receptors are functionally coupled to steroidogenesis. PMID:2169244

  7. Solid-phase receptor-based assay for the detection of cyclic imines by chemiluminescence, fluorescence, or colorimetry.

    PubMed

    Rodríguez, Laura P; Vilariño, Natalia; Molgó, Jordi; Aráoz, Rómulo; Antelo, Alvaro; Vieytes, Mercedes R; Botana, Luis M

    2011-08-01

    The spirolides and gymnodimines are marine phycotoxins included in the group of cyclic imines. The toxicity of these compounds to humans is still unknown, although their toxicity by intraperitoneal injection in rodents is very high. A receptor-based method was developed using the competition of the 13-desmethyl spirolide C with biotin-labeled α-bungarotoxin for binding to nicotinic acetylcholine receptors and the immobilization of the α-bungarotoxin-receptor complex on streptavidin-coated surfaces. The quantification of the immobilized receptor can be achieved using a specific antibody. Finally, after the addition of a secondary antibody labeled with horseradish peroxidase, three alternative substrates of this enzyme generate a chemiluminescent, fluorescent, or colorimetric signal. The assay performs well in shellfish extracts and the detection range is 5-150 nM of 13-desmethyl spirolide C in shellfish extracts, which is at least 5 times more sensitive than the existing fluorescence polarization assay. This assay can also detect gymnodimine, although with 10 times lower sensitivity than the spirolide. The detection of cyclic imines with microplate assays would be useful for screening purposes in order to reduce the number of samples to be processed by bioassays or analytical methods.

  8. 76 FR 19237 - Food Labeling; Calorie Labeling of Articles of Food in Vending Machines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ... 11 and 101 Food Labeling; Calorie Labeling of Articles of Food in Vending Machines; Proposed Rule #0... Labeling; Calorie Labeling of Articles of Food in Vending Machines AGENCY: Food and Drug Administration, HHS. ACTION: Proposed rule. SUMMARY: To implement the vending machine labeling provisions of the...

  9. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1987-05-22

    This invention involved a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide in activators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  10. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, Joanna S.; MacGregor, Robert R.; Wolf, Alfred P.; Langstrom, Bengt

    1990-01-01

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  11. Metrics for Labeled Markov Systems

    NASA Technical Reports Server (NTRS)

    Desharnais, Josee; Jagadeesan, Radha; Gupta, Vineet; Panangaden, Prakash

    1999-01-01

    Partial Labeled Markov Chains are simultaneously generalizations of process algebra and of traditional Markov chains. They provide a foundation for interacting discrete probabilistic systems, the interaction being synchronization on labels as in process algebra. Existing notions of process equivalence are too sensitive to the exact probabilities of various transitions. This paper addresses contextual reasoning principles for reasoning about more robust notions of "approximate" equivalence between concurrent interacting probabilistic systems. The present results indicate that:We develop a family of metrics between partial labeled Markov chains to formalize the notion of distance between processes. We show that processes at distance zero are bisimilar. We describe a decision procedure to compute the distance between two processes. We show that reasoning about approximate equivalence can be done compositionally by showing that process combinators do not increase distance. We introduce an asymptotic metric to capture asymptotic properties of Markov chains; and show that parallel composition does not increase asymptotic distance.

  12. Positron emitter labeled enzyme inhibitors

    SciTech Connect

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.; Langstrom, B.

    1990-04-03

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  13. Learning With Auxiliary Less-Noisy Labels.

    PubMed

    Duan, Yunyan; Wu, Ou

    2016-04-06

    Obtaining a sufficient number of accurate labels to form a training set for learning a classifier can be difficult due to the limited access to reliable label resources. Instead, in real-world applications, less-accurate labels, such as labels from nonexpert labelers, are often used. However, learning with less-accurate labels can lead to serious performance deterioration because of the high noise rate. Although several learning methods (e.g., noise-tolerant classifiers) have been advanced to increase classification performance in the presence of label noise, only a few of them take the noise rate into account and utilize both noisy but easily accessible labels and less-noisy labels, a small amount of which can be obtained with an acceptable added time cost and expense. In this brief, we propose a learning method, in which not only noisy labels but also auxiliary less-noisy labels, which are available in a small portion of the training data, are taken into account. Based on a flipping probability noise model and a logistic regression classifier, this method estimates the noise rate parameters, infers ground-truth labels, and learns the classifier simultaneously in a maximum likelihood manner. The proposed method yields three learning algorithms, which correspond to three prior knowledge states regarding the less-noisy labels. The experiments show that the proposed method is tolerant to label noise, and outperforms classifiers that do not explicitly consider the auxiliary less-noisy labels.

  14. Cyclic Segregation State in Vertically Vibrated Binary Granular Mixtures

    NASA Astrophysics Data System (ADS)

    Shi, Qingfan; Pan, Beicheng; Lu, Changhong; Sun, Gang

    2014-01-01

    In this paper, the vertically vibrated binary granular mixtures at atmospheric pressure are studied experimentally. We find a nonstationary segregation state, of which the structure changes with time cyclically. The period of the cyclic segregation is measured and its variation with the vibration conditions is shown. The transition between the segregation states is also discussed, and a phase diagram on the plot of frequency against acceleration amplitude is given. In order to observe the effect of air flow in the segregation process, an alternative container with ventilated bottom is designed. Our experiments show that both regions of the Brazil nut segregation state and the cyclic segregation state shrink obviously by use of the latter container and disappear completely if the whole system is placed in vacuum. These results testify that the air pressure plays a positive role in both the Brazil nut effect and cyclic segregation.

  15. Quantum Codes From Cyclic Codes Over The Ring R2

    NASA Astrophysics Data System (ADS)

    Altinel, Alev; Güzeltepe, Murat

    2016-10-01

    Let R 2 denotes the ring F 2 + μF 2 + υ2 + μυF 2 + wF 2 + μwF 2 + υwF 2 + μυwF2. In this study, we construct quantum codes from cyclic codes over the ring R2, for arbitrary length n, with the restrictions μ2 = 0, υ2 = 0, w 2 = 0, μυ = υμ, μw = wμ, υw = wυ and μ (υw) = (μυ) w. Also, we give a necessary and sufficient condition for cyclic codes over R2 that contains its dual. As a final point, we obtain the parameters of quantum error-correcting codes from cyclic codes over R2 and we give an example of quantum error-correcting codes form cyclic codes over R 2.

  16. Riboflavin in cyclic vomiting syndrome: efficacy in three children.

    PubMed

    Martinez-Esteve Melnikova, Anastasia; Schäppi, Michela G; Korff, Christian

    2016-01-01

    Cyclic vomiting syndrome is an episodic disorder considered to be a migraine variant. Riboflavin is efficient in the prophylactic treatment of migraines in adults. We describe the effectiveness and tolerance of riboflavin treatment in three children with cyclic vomiting syndrome. All of them fulfilled the diagnosis criteria for cyclic vomiting syndrome. They received prophylactic monotherapy with riboflavin for at least 12 months. Excellent response and tolerability was observed. Based on clinical observation in three cases, riboflavin may be an effective and safe prophylactic treatment for children with cyclic vomiting syndrome. CVS is one of the "childhood periodic syndromes" classified as a migraine subtype by the International Headache Society. Riboflavin is currently used as a prophylactic treatment in patients with migraine. Riboflavin may be an effective and safe prophylactic treatment for children with CVS. Increasing doses of riboflavin and long periods of prophylaxis may be needed in some children..

  17. Rapid purification of iodinated ligands for cyclic nucleotide radioimmunoassays

    SciTech Connect

    Wilson, S.P.

    1988-01-01

    The tyrosine methyl esters of succinyl cyclic AMP and succinyl cyclic GMP were iodinated by the chloramine T method and individually applied to C18 cartridges. A solution of 1-propanol/0.1 M sodium acetate pH 4.75 (17.5:82.5) was then pumped onto each cartridge and the eluate collected. A large peak of radioactivity, containing primarily the monoiodo and diiodo derivatives, was eluted. Radioactivity in peak fractions was greater than or equal to 95% the monoiodo derivative and represented 20 to 25% of the starting radioactivity. Contamination by the native cyclic nucleotide analogs was less than 5%. These peak fractions containing primarily monoiodinated products worked well in cyclic nucleotide radioimmunoassays. This fractionation required less than 30 min.

  18. Cyclic deformation, fracture, and nondestructive evaluation of advanced materials

    SciTech Connect

    Mitchell, M.R.; Buck, O.

    1992-01-01

    Papers are presented on cyclic fatigue of alumnia, fatigue crack growth in ceramics and ceramic-matrix composites, fatigue test methodology and results for ceramic matrix composites at room and elevated temperatures, and modeling crack growth resistance in ceramics and ceramic-matrix composites. Attention is also given to thermomechanical cyclic deformation of metal-matrix composites, the effect of tensile mean stress on the fatigue behavior of single-crystal and directionally solidified superalloys, the influence of constituent properties on the compression behavior of aluminates with discontinuities, and cyclic creep effects in single-overlap bonded joints under constant-amplitude testing. Other papers discuss an ultrasonic wave technique to assess cyclic-load fatigue damage in silicon-carbide whisker-reinforced 2124 aluminum alloy composites, nondestructive characterization for metal-matrix composite fabrication, NDE of a ceramic matrix composite material, and split spectrum processing of backscattered Rayleigh wave signals to improve detectability of fatigue microcracks.

  19. Cyclical Cohabitation Among Unmarried Parents in Fragile Families.

    PubMed

    Nepomnyaschy, Lenna; Teitler, Julien

    2013-10-01

    Building on past research suggesting that cohabitation is an ambiguous family form, the authors examined an understudied residential pattern among unmarried parents: cyclical cohabitation, in which parents have multiple cohabitation spells with each other. Using 9 years of panel data from the Fragile Families and Child Wellbeing Study (N = 2,084), they found that 10% of all parents with nonmarital births, and nearly a quarter of those living together when the child is 9 years old, are cyclical cohabitors. Cyclically cohabiting mothers reported more material hardships than mothers in most other relationship patterns but also reported more father involvement with children. On all measures of child well-being, except grade retention, children of cyclically cohabiting parents fared no worse than children of stably cohabiting biological parents and did not differ significantly from any other group.

  20. Cyclical Cohabitation Among Unmarried Parents in Fragile Families

    PubMed Central

    Nepomnyaschy, Lenna; Teitler, Julien

    2013-01-01

    Building on past research suggesting that cohabitation is an ambiguous family form, the authors examined an understudied residential pattern among unmarried parents: cyclical cohabitation, in which parents have multiple cohabitation spells with each other. Using 9 years of panel data from the Fragile Families and Child Wellbeing Study (N = 2,084), they found that 10% of all parents with nonmarital births, and nearly a quarter of those living together when the child is 9 years old, are cyclical cohabitors. Cyclically cohabiting mothers reported more material hardships than mothers in most other relationship patterns but also reported more father involvement with children. On all measures of child well-being, except grade retention, children of cyclically cohabiting parents fared no worse than children of stably cohabiting biological parents and did not differ significantly from any other group. PMID:25067855

  1. Cyclic AMP Signaling: A Molecular Determinant of Peripheral Nerve Regeneration

    PubMed Central

    Knott, Eric P.; Assi, Mazen; Pearse, Damien D.

    2014-01-01

    Disruption of axonal integrity during injury to the peripheral nerve system (PNS) sets into motion a cascade of responses that includes inflammation, Schwann cell mobilization, and the degeneration of the nerve fibers distal to the injury site. Yet, the injured PNS differentiates itself from the injured central nervous system (CNS) in its remarkable capacity for self-recovery, which, depending upon the length and type of nerve injury, involves a series of molecular events in both the injured neuron and associated Schwann cells that leads to axon regeneration, remyelination repair, and functional restitution. Herein we discuss the essential function of the second messenger, cyclic adenosine monophosphate (cyclic AMP), in the PNS repair process, highlighting the important role the conditioning lesion paradigm has played in understanding the mechanism(s) by which cyclic AMP exerts its proregenerative action. Furthermore, we review the studies that have therapeutically targeted cyclic AMP to enhance endogenous nerve repair. PMID:25177696

  2. Cyclical Behavior of Productivity in the Machine Tool Industry.

    ERIC Educational Resources Information Center

    Duke, John; Brand, Horst

    1981-01-01

    Productivity growth was slow during 1958-80, partly because of the industry's tendency to retain skilled workers during cyclical downturns; computers and other electronic equipment aided production, but diffusion of such innovations has been slow. (Author)

  3. Safety Discrete Event Models for Holonic Cyclic Manufacturing Systems

    NASA Astrophysics Data System (ADS)

    Ciufudean, Calin; Filote, Constantin

    In this paper the expression “holonic cyclic manufacturing systems” refers to complex assembly/disassembly systems or fork/join systems, kanban systems, and in general, to any discrete event system that transforms raw material and/or components into products. Such a system is said to be cyclic if it provides the same sequence of products indefinitely. This paper considers the scheduling of holonic cyclic manufacturing systems and describes a new approach using Petri nets formalism. We propose an approach to frame the optimum schedule of holonic cyclic manufacturing systems in order to maximize the throughput while minimize the work in process. We also propose an algorithm to verify the optimum schedule.

  4. The Cyclical Relationship Approach in Teaching Basic Accounting Principles.

    ERIC Educational Resources Information Center

    Golen, Steven

    1981-01-01

    Shows how teachers can provide a more meaningful presentation of various accounting principles by illustrating them through a cyclical relationship approach. Thus, the students see the entire accounting relationship as a result of doing business. (CT)

  5. Leishmania β-1,2-mannan is assembled on a mannose-cyclic phosphate primer

    PubMed Central

    Sernee, M. Fleur; Ralton, Julie E.; Dinev, Zoran; Khairallah, George N.; O’Hair, Richard A.; Williams, Spencer J.; McConville, Malcolm J.

    2006-01-01

    Infective stages of the protozoan parasite Leishmania spp. accumulate a class of β-1,2-mannan oligosaccharides as their major carbohydrate reserve material. Here, we describe the biosynthesis of Leishmania mannan. Mannan precursors were identified by metabolic labeling of Leishmania mexicana promastigotes with [3H]mannose. Label was initially incorporated into a phosphomannose primer and short phosphorylated β-1,2-mannan oligomers that were two to five residues long. Analysis of the mannan primer by Fourier transform ion-cyclotron resonance MS and various enzymatic and chemical treatments and comparison with authentic mannose (Man) phosphates indicated the presence of Man-α-1,4-cyclic phosphate. This primer was synthesized from Man-6-phosphate by means of Man-1-phosphate in a cell-free system. Short mannan chains containing the primer were subsequently dephosphorylated and then further elongated by GDP-Man-dependent transferases in vivo and in the cell-free system. The synthesis of this glycan primer likely constitutes a key regulatory step in mannan biosynthesis and is a potential target for antileishmanial drugs. PMID:16766650

  6. Novel Bifunctional Cyclic Chelator for 89Zr Labeling–Radiolabeling and Targeting Properties of RGD Conjugates

    PubMed Central

    2015-01-01

    Within the last years 89Zr has attracted considerable attention as long-lived radionuclide for positron emission tomography (PET) applications. So far desferrioxamine B (DFO) has been mainly used as bifunctional chelating system. Fusarinine C (FSC), having complexing properties comparable to DFO, was expected to be an alternative with potentially higher stability due to its cyclic structure. In this study, as proof of principle, various FSC-RGD conjugates targeting αvß3 integrins were synthesized using different conjugation strategies and labeled with 89Zr. In vitro stability, biodistribution, and microPET/CT imaging were evaluated using [89Zr]FSC-RGD conjugates or [89Zr]triacetylfusarinine C (TAFC). Quantitative 89Zr labeling was achieved within 90 min at room temperature. The distribution coefficients of the different radioligands indicate hydrophilic character. Compared to [89Zr]DFO, [89Zr]FSC derivatives showed excellent in vitro stability and resistance against transchelation in phosphate buffered saline (PBS), ethylenediaminetetraacetic acid solution (EDTA), and human serum for up to 7 days. Cell binding studies and biodistribution as well as microPET/CT imaging experiments showed efficient receptor-specific targeting of [89Zr]FSC-RGD conjugates. No bone uptake was observed analyzing PET images indicating high in vivo stability. These findings indicate that FSC is a highly promising chelator for the development of 89Zr-based PET imaging agents. PMID:25941834

  7. Cyclic Peptidomimetics and Pseudopeptides from Multicomponent Reactions

    NASA Astrophysics Data System (ADS)

    Wessjohann, Ludger A.; Rhoden, Cristiano R. B.; Rivera, Daniel G.; Vercillo, Otilie Eichler

    Multicomponent reactions (MCRs) that provide in the final product amides are suitable to produce peptides and peptide-like moieties. The Passerini and Staudinger reactions provide one amide bond, and the Ugi-four-component reaction generates two amides from three or even four (or more) components, respectively. The Ugi-reaction thus is most important to produce peptides and peptoids while the Passerini reaction is useful to generate depsipeptoid moieties. In order to produce cyclic peptides and pseudopeptides, the linear peptidic MCR products have to be cyclized, usually with the help of bifunctional or activatable building blocks. Orthogonal but cyclizable secondary functionalities that need no protection in isonitrile MCRs commonly include alkenes (for ring closing metathesis), azide/alkyne (for Huisgen click reactions) or dienes and enoates (Diels-Alder) etc. If MCR-reactive groups are to be used also for the cyclisation, monoprotected bifunctional building blocks are used and deprotected after the MCR, e.g. for Ugi reactions as Ugi-Deprotection-Cyclisation (UDC). Alternatively one of the former building blocks or functional groups generated by the MCR can be activated. Most commonly these are activated amides (from so-called convertible isonitriles) which can be used e.g. for Ugi-Activation-Cyclisation (UAC) protocols, or most recently for a simultaneous use of both strategies Ugi-Deprotection/Activation-Cyclisation (UDAC). These methods mostly lead to small, medicinally relevant peptide turn mimics. In an opposing strategy, the MCR is rather used as ring-closing reaction, thereby introducing a (di-)peptide moiety. Most recently these processes have been combined to use MCRs for both, linear precursor synthesis and cyclisation. These multiple MCR approaches allow the most efficient and versatile one pot synthesis of macrocyclic pseudopeptides known to date.

  8. Behavior of granular materials under cyclic shear.

    PubMed

    Mueggenburg, Nathan W

    2005-03-01

    The design and development of a parallel plate shear cell for the study of large-scale shear flows in granular materials is presented. The parallel plate geometry allows for shear studies without the effects of curvature found in the more common Couette experiments. A system of independently movable slats creates a well with side walls that deform in response to the motions of grains within the pack. This allows for true parallel plate shear with minimal interference from the containing geometry. The motions of the side walls also allow for a direct measurement of the velocity profile across the granular pack. Results are presented for applying this system to the study of transients in granular shear and for shear-induced crystallization. Initial shear profiles are found to vary from packing to packing, ranging from a linear profile across the entire system to an exponential decay with a width of approximately six bead diameters. As the system is sheared, the velocity profile becomes much sharper, resembling an exponential decay with a width of roughly three bead diameters. Further shearing produces velocity profiles which can no longer be fit to an exponential decay, but are better represented as a Gaussian decay or error function profile. Cyclic shear is found to produce large-scale ordering of the granular pack, which has a profound impact on the shear profile. There exist periods of time in which there is slipping between layers as well as periods of time in which the layered particles lock together resulting in very little relative motion.

  9. Coping with cyclic oxygen availability: evolutionary aspects.

    PubMed

    Flück, Martin; Webster, Keith A; Graham, Jeffrey; Giomi, Folco; Gerlach, Frank; Schmitz, Anke

    2007-10-01

    Both the gradual rise in atmospheric oxygen over the Proterozoic Eon as well as episodic fluctuations in oxygen over several million-year time spans during the Phanerozoic Era, have arguably exerted strong selective forces on cellular and organismic respiratory specialization and evolution. The rise in atmospheric oxygen, some 2 billion years after the origin of life, dramatically altered cell biology and set the stage for the appearance of multicelluar life forms in the Vendian (Ediacaran) Period of the Neoproterozoic Era. Over much of the Paleozoic, the level of oxygen in the atmosphere was near the present atmospheric level (21%). In the Late Paleozoic, however, there were extended times during which the level of atmospheric oxygen was either markedly lower or markedly higher than 21%. That these Paleozoic shifts in atmospheric oxygen affected the biota is suggested by the correlations between: (1) Reduced oxygen and the occurrences of extinctions, a lowered biodiversity and shifts in phyletic succession, and (2) During hyperoxia, the corresponding occurrence of phenomena such as arthropod gigantism, the origin of insect flight, and the evolution of vertebrate terrestriality. Basic similarities in features of adaptation to hyopoxia, manifest in living organisms at levels ranging from genetic and cellular to physiological and behavioral, suggest the common and early origin of a suite of adaptive mechanisms responsive to fluctuations in ambient oxygen. Comparative integrative approaches addressing the molecular bases of phenotypic adjustments to cyclic oxygen fluctuation provide broad insight into the incremental steps leading to the early evolution of homeostatic respiratory mechanisms and to the specialization of organismic respiratory function.

  10. A New Interstellar Cyclic Molecule, Ethylene Oxide

    NASA Astrophysics Data System (ADS)

    Dickens, J. E.; Irvine, W. M.; Ohishi, M.; Ikeda, M.; Ishikawa, S.; Nummelin, A.; Hjalmarson, A.

    1997-12-01

    Ethylene oxide (c-C2H4O) is only the fourth known ring molecule identified in the interstellar medium, detected in the Galactic Center cloud SgrB2(N) by Dickens et al. (1997). It is the higher energy isomer of both the more familiar interstellar species acetaldehyde (CH3CHO) and the as yet undetected molecule vinyl alcohol (CH2CHOH). Dickens et al. (1997) reported a c-C2H4O molecular column density about an order of magnitude less than that reported for CH3CHO in SgrB2(N). This is a factor of 200 larger than the predictions of the new standard gas phase chemistry model of Lee, Bettens, and Herbst (1996), suggesting that the formation of c-C2H4O may be related to molecular formation on interstellar grains. We present observations of the c-C2H4O to CH3CHO abundance ratio in 5 additional molecular clouds. The data were taken in October 1997 with the Swedish-European Submillimeter Telescope in Chile. The confirmation of ethylene oxide in molecular clouds provides an appealing scenario for the first link in the chain of reactions leading to the origin of life, since it has been suggested as a possible pathway to the formation of the related cyclic molecule oxiranecarbonitrile (c-C3H3NO; cf., Dickens et al. 1996), a precursor to the synthesis of sugar phosphates which comprise the backbone of our molecular genetic structure. References: Dickens, J.E., Irvine, W.M., Ohishi, M., Ikeda, M., Ishikawa, S., Nummelin, A., and Hjalmarson, A. 1997, Astrophys. J., 489 (in press). Dickens, J.E. et al. 1996, Orig. Life Evol. Biosphere, 26, 97. Lee, H.-H., Bettens, R.P.A., and Herbst, E. 1996, Astron. Astrophys. Supp., 119, 111.

  11. Highly Efficient Protein Misfolding Cyclic Amplification

    PubMed Central

    Ostapchenko, Valeriy G.; Savtchenk, Regina; Alexeeva, Irina; Rohwer, Robert G.; Baskakov, Ilia V.

    2011-01-01

    Protein misfolding cyclic amplification (PMCA) provides faithful replication of mammalian prions in vitro and has numerous applications in prion research. However, the low efficiency of conversion of PrPC into PrPSc in PMCA limits the applicability of PMCA for many uses including structural studies of infectious prions. It also implies that only a small sub-fraction of PrPC may be available for conversion. Here we show that the yield, rate, and robustness of prion conversion and the sensitivity of prion detection are significantly improved by a simple modification of the PMCA format. Conducting PMCA reactions in the presence of Teflon beads (PMCAb) increased the conversion of PrPC into PrPSc from ∼10% to up to 100%. In PMCAb, a single 24-hour round consistently amplified PrPSc by 600-700-fold. Furthermore, the sensitivity of prion detection in one round (24 hours) increased by 2-3 orders of magnitude. Using serial PMCAb, a 1012-fold dilution of scrapie brain material could be amplified to the level detectible by Western blotting in 3 rounds (72 hours). The improvements in amplification efficiency were observed for the commonly used hamster 263K strain and for the synthetic strain SSLOW that otherwise amplifies poorly in PMCA. The increase in the amplification efficiency did not come at the expense of prion replication specificity. The current study demonstrates that poor conversion efficiencies observed previously have not been due to the scarcity of a sub-fraction of PrPC susceptible to conversion nor due to limited concentrations of essential cellular cofactors required for conversion. The new PMCAb format offers immediate practical benefits and opens new avenues for developing fast ultrasensitive assays and for producing abundant quantities of PrPSc in vitro. PMID:21347353

  12. 78 FR 66826 - Prior Label Approval System: Generic Label Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... product as ``organic'' or containing organic ingredients; (3) claims that are undefined in FSIS... labeling errors resulted from production mistakes, such as packaging the product in the wrong box. More... poultry products inspection regulations to expand the circumstances in which FSIS will generically...

  13. A computer program for cyclic plasticity and structural fatigue analysis

    NASA Technical Reports Server (NTRS)

    Kalev, I.

    1980-01-01

    A computerized tool for the analysis of time independent cyclic plasticity structural response, life to crack initiation prediction, and crack growth rate prediction for metallic materials is described. Three analytical items are combined: the finite element method with its associated numerical techniques for idealization of the structural component, cyclic plasticity models for idealization of the material behavior, and damage accumulation criteria for the fatigue failure.

  14. Microgravity changes in heart structure and cyclic-AMP metabolism

    NASA Technical Reports Server (NTRS)

    Philpott, D. E.; Fine, A.; Kato, K.; Egnor, R.; Cheng, L.

    1985-01-01

    The effects of microgravity on cardiac ultrastructure and cyclic AMP metabolism in tissues of rats flown on Spacelab 3 are reported. Light and electron microscope studies of cell structure, measurements of low and high Km phosphodiesterase activity, cyclic AMP-dependent protein kinase activity, and regulatory subunit compartmentation show significant deviations in flight animals when compared to ground controls. The results indicate that some changes have occurred in cellular responses associated with catecholamine receptor interactions and intracellular signal processing.

  15. A rare cyclic recurrent hematuria case; bladder endometriosis

    PubMed Central

    Akpınar, Süha; Çelebioğlu, Emre

    2015-01-01

    Endometriosis is a benign gynecological disease that is characterized by the presence of functional endometrial tissue outside the uterus. Although the ovaries and uterine ligaments are the most common locations, urinary tract involvement especially the bladder endometriosis is a rare entity in women of reproductive age with clinical symptoms of cyclical urgency, hematuria and suprapubic pain. We herein present magnetic resonance imaging (MRI) findings of spontaneous bladder endometriosis case with cyclical hematuria symptoms. PMID:26029655

  16. Observation of the Cyclic Water Hexamer in Solid Parahydrogen

    DTIC Science & Technology

    2007-11-02

    of-the cyclic -water hexamer, "cyc-(HO)&" expect minimal perturbations t6 the dopant’s structure and via its intfrared (IR) absorption in liquid helium ...red by = 15 cmf𔃻 from the absorptions of cyclic water clusters in liquid ihelium drolets [P. Nauta and R.E. Miller, Science 287, 293 (2600)]; this...dynamics, and hydrogen -bond (H-bond) interactions with. in- the resulting absence of permanent electric multipoles contrib- creasingg cluster size; one

  17. Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

    PubMed Central

    Koopmanschap, Gijs; Ruijter, Eelco

    2014-01-01

    Summary In the recent past, the design and synthesis of peptide mimics (peptidomimetics) has received much attention. This because they have shown in many cases enhanced pharmacological properties over their natural peptide analogues. In particular, the incorporation of cyclic constructs into peptides is of high interest as they reduce the flexibility of the peptide enhancing often affinity for a certain receptor. Moreover, these cyclic mimics force the molecule into a well-defined secondary structure. Constraint structural and conformational features are often found in biological active peptides. For the synthesis of cyclic constrained peptidomimetics usually a sequence of multiple reactions has been applied, which makes it difficult to easily introduce structural diversity necessary for fine tuning the biological activity. A promising approach to tackle this problem is the use of multicomponent reactions (MCRs), because they can introduce both structural diversity and molecular complexity in only one step. Among the MCRs, the isocyanide-based multicomponent reactions (IMCRs) are most relevant for the synthesis of peptidomimetics because they provide peptide-like products. However, these IMCRs usually give linear products and in order to obtain cyclic constrained peptidomimetics, the acyclic products have to be cyclized via additional cyclization strategies. This is possible via incorporation of bifunctional substrates into the initial IMCR. Examples of such bifunctional groups are N-protected amino acids, convertible isocyanides or MCR-components that bear an additional alkene, alkyne or azide moiety and can be cyclized via either a deprotection–cyclization strategy, a ring-closing metathesis, a 1,3-dipolar cycloaddition or even via a sequence of multiple multicomponent reactions. The sequential IMCR-cyclization reactions can afford small cyclic peptide mimics (ranging from four- to seven-membered rings), medium-sized cyclic constructs or peptidic macrocycles

  18. OPERATIONAL AMPLIFIER CIRCUITS FOR CONTROLLED POTENTIAL CYCLIC VOLTAMMETRY, II,

    DTIC Science & Technology

    are described, a mechanical or motor driven unit, and an OA integrator network which is more versatile. Cyclic voltammetry appears to have great...Several practical, inexpensive, operational amplifier (OA) circuits are described which are particularly useful in single sweep and cyclic ... voltammetry at stationary electrodes. Specific adaptations of OA’s to electroanalytical instrumentation were made some time ago by Booman and coworkers and

  19. Cyclic voltammetry characterization of metal complex imprinted polymer.

    PubMed

    Zeng, Yi Ning; Zheng, Ning; Osborne, Peter G; Li, Yuan Zong; Chang, Wen Bao; Wen, Mei Juan

    2002-01-01

    Polymer capable of specific binding to Cu(2+)-2, 2'-dipyridyl complex was prepared by molecular imprinting technology. The binding specificity of the polymer to the template (Cu(2+)-2, 2'-dipyridyl complex) was investigated by cyclic voltammetric scanning using the carbon paste electrode modified by polymer particles in phosphate buffer solution. Factors that influence rebinding of the imprinted polymer were explored. The results demonstrated that cyclic voltammetry was an efficient approach to explore interactions between template and imprinted polymers.

  20. Swimming in spacetime: motion by cyclic changes in body shape.

    PubMed

    Wisdom, Jack

    2003-03-21

    Cyclic changes in the shape of a quasi-rigid body on a curved manifold can lead to net translation and/or rotation of the body. The amount of translation depends on the intrinsic curvature of the manifold. Presuming spacetime is a curved manifold as portrayed by general relativity, translation in space can be accomplished simply by cyclic changes in the shape of a body, without any external forces.

  1. Signal Classification in Fading Channels Using Cyclic Spectral Analysis

    DTIC Science & Technology

    2009-07-01

    efficient algorithms to detect and classify an OFDM signal based on its cyclic prefix through the use of a simple autocorrelation procedure [21–23...we focus on the case of an OFDM signal transmitted with no cyclic prefix. Therefore, an intermediate stage is needed between the SOF- based ...classifications and the HOCS- based classifications. A simple yet effective method to distinguish OFDM signals from the single carrier signals in question is

  2. Microgravity changes in heart structure and cyclic-AMP metabolism

    NASA Technical Reports Server (NTRS)

    Philpott, D. E.; Fine, A.; Kato, K.; Egnor, R.; Cheng, L.

    1985-01-01

    The effects of microgravity on cardiac ultrastructure and cyclic AMP metabolism in tissues of rats flown on Spacelab 3 are reported. Light and electron microscope studies of cell structure, measurements of low and high Km phosphodiesterase activity, cyclic AMP-dependent protein kinase activity, and regulatory subunit compartmentation show significant deviations in flight animals when compared to ground controls. The results indicate that some changes have occurred in cellular responses associated with catecholamine receptor interactions and intracellular signal processing.

  3. Self-assembly of cyclic rod-coil diblock copolymers.

    PubMed

    He, Linli; Chen, Zenglei; Zhang, Ruifen; Zhang, Linxi; Jiang, Zhouting

    2013-03-07

    The phase behavior of cyclic rod-coil diblock copolymer melts is investigated by the dissipative particle dynamics simulation. In order to understand the effect of chain topological architecture better, we also study the linear rod-coil system. The comparison of the calculated phase diagrams between the two rod-coil copolymers reveals that the order-disorder transition point (χN)ODT for cyclic rod-coil diblock copolymers is always higher than that of equivalent linear rod-coil diblocks. In addition, the phase diagram for cyclic system is more "symmetrical," due to the topological constraint. Moreover, there are significant differences in the self-assembled overall morphologies and the local molecular arrangements. For example, frod = 0.5, both lamellar structures are formed while rod packing is different greatly in cyclic and linear cases. The lamellae with rods arranged coplanarly into bilayers occurs in cyclic rod-coil diblocks, while the lamellar structure with rods arranged end by end into interdigitated bilayers appears in linear counterpart. In both the lamellar phases, the domain size ratio of cyclic to linear diblocks is ranged from 0.63 to 0.70. This is attributed to that the cyclic architecture with the additional junction increases the contacts between incompatible blocks and prevents the coil chains from expanding as much as the linear cases. As frod = 0.7, the hexagonally packed cylinder is observed for cyclic rod-coil diblocks, while liquid-crystalline smectic A lamellar phase is formed in linear system. As a result, the cyclization of a linear rod-coil block copolymer can induce remarkable differences in the self-assembly behavior and also diversify its physical properties and applications greatly.

  4. Food labeling: gluten-free labeling of foods. Final rule.

    PubMed

    2013-08-05

    The Food and Drug Administration (FDA or we) is issuing a final rule to define the term "gluten-free'' for voluntary use in the labeling of foods. The final rule defines the term "gluten-free'' to mean that the food bearing the claim does not contain an ingredient that is a gluten-containing grain (e.g., spelt wheat); an ingredient that is derived from a gluten-containing grain and that has not been processed to remove gluten (e.g., wheat flour); or an ingredient that is derived from a gluten-containing grain and that has been processed to remove gluten (e.g., wheat starch), if the use of that ingredient results in the presence of 20 parts per million (ppm) or more gluten in the food (i.e., 20 milligrams (mg) or more gluten per kilogram (kg) of food); or inherently does not contain gluten; and that any unavoidable presence of gluten in the food is below 20 ppm gluten (i.e., below 20 mg gluten per kg of food). A food that bears the claim "no gluten,'' "free of gluten,'' or "without gluten'' in its labeling and fails to meet the requirements for a "gluten-free'' claim will be deemed to be misbranded. In addition, a food whose labeling includes the term "wheat'' in the ingredient list or in a separate "Contains wheat'' statement as required by a section of the Federal Food, Drug, and Cosmetic Act (the FD&C Act) and also bears the claim "gluten-free'' will be deemed to be misbranded unless its labeling also bears additional language clarifying that the wheat has been processed to allow the food to meet FDA requirements for a "gluten-free'' claim. Establishing a definition of the term "gluten-free'' and uniform conditions for its use in food labeling will help ensure that individuals with celiac disease are not misled and are provided with truthful and accurate information with respect to foods so labeled. We are issuing the final rule under the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA).

  5. A New Component Labelling And Merging Algorithm

    NASA Astrophysics Data System (ADS)

    Lochovsky, Amelia F.

    1987-10-01

    Component labelling is an important part of region analysis in image processing. Component labelling consists of assigning labels to pixels in the image such that adjacent pixels are given the same labels. There are various approaches to component labelling. Some require random access to the processed image; some assume special structure of the image such as a quad tree. Algorithms based on sequential scan of the image are attractive to hardware implementation. One method of labelling is based on a fixed size local window which includes the previous line. Due to the fixed size window and the sequential fashion of the labelling process, different branches of the same object may be given different labels and later found to be connected to each other. These labels are con-sidered to be equivalent and must later be collected to correctly represent one single object. This approach can be found in [F,FE,R]. Assume an input binary image of size NxM. Using these labelling algorithms, the number of equivalent pair generated is bounded by O(N*M). The number of distinct labels is also bounded by O(N*M). There is no known algorithm that merge the equivalent label pairs in time linear to the number of pairs, that is in time bounded by O(N*M). We propose a new labelling algorithm which interleaves the labelling with the merging process. The labelling and the merging are combined in one algorithm. Merged label information is kept in an equivalent table which is used to guide the labelling. In general , the algorithm produces fewer equivalent label pairs. The combined labelling and merging algorithm is O(N*M), where NxM is the size of the image. Section II describes the algorithm. Section III gives some examples We discuss implementation issues in section IV and further discussion and conclusion are given in Section V.

  6. Self-Assembled DNA Tetrahedral Scaffolds for the Construction of Electrochemiluminescence Biosensor with Programmable DNA Cyclic Amplification.

    PubMed

    Feng, Qiu-Mei; Guo, Yue-Hua; Xu, Jing-Juan; Chen, Hong-Yuan

    2017-05-24

    A novel DNA tetrahedron-structured electrochemiluminescence (ECL) platform for bioanalysis with programmable DNA cyclic amplification was developed. In this work, glucose oxidase (GOD) was labeled to a DNA sequence (S) as functional conjugation (GOD-S), which could hybridize with other DNA sequences (L and P) to form GOD-S:L:P probe. In the presence of target DNA and a help DNA (A), the programmable DNA cyclic amplification was activated and released GOD-S via toehold-mediated strand displacement. Then, the obtained GOD-S was further immobilized on the DNA tetrahedral scaffolds with a pendant capture DNA and Ru(bpy)3(2+)-conjugated silica nanoparticles (RuSi NPs) decorated on the electrode surface. Thus, the amount of GOD-S assembled on the electrode surface depended on the concentration of target DNA and GOD could catalyze glucose to generate H2O2 in situ. The ECL signal of Ru(bpy)3(2+)-TPrA system was quenched by the presence of H2O2. By integrating the programmable DNA cyclic amplification and in situ generating H2O2 as Ru(bpy)3(2+) ECL quencher, a sensitive DNA tetrahedron-structured ECL sensing platform was proposed for DNA detection. Under optimized conditions, this biosensor showed a wide linear range from 100 aM to 10 pM with a detection limit of 40 aM, indicating a promising application in DNA analysis. Furthermore, by labeling GOD to different recognition elements, the proposed strategy could be used for the detection of various targets. Thus, this programmable cascade amplification strategy not only retains the high selectivity and good capturing efficiency of tetrahedral-decorated electrode surface but also provides potential applications in the construction of ECL biosensor.

  7. Cyclic nucleotide-gated channels in non-sensory organs.

    PubMed

    Kraus-Friedmann, N

    2000-03-01

    Cyclic nucleotide-gated channels represent a class of ion channels activated directly by the binding of either cyclic-GMP or cyclic-AMP. They carry both mono and divalent cations, but select calcium over sodium. In the majority of the cases studied, binding of cyclic nucleotides to the channel results in the opening of the channel and the influx of calcium. As a consequence, cytosolic free calcium levels increase leading to the modifications of calcium-dependent processes. This represents and important link in the chain of events leading to the physiological response. Cyclic nucleotide-gated channels were discovered in sensory cell types, in the retina, and in olfactory cells, and were extensively studied in those cells. However, it is becoming increasingly evident that such channels are present not only in sensory systems, but in most, if not all, cell types where cyclic nucleotides play a role in signal transduction. A hypothesis is presented here which attributes physiological importance to these channels in non-sensory organs. Four examples of such channels in non-sensory cells are discussed in detail: those in the liver, in the heart, in the brain, and in the testis with the emphasis on the possible physiological roles that these channels might have in these organs.

  8. Asymmetric synthesis of gem-diaryl substituted cyclic sulfamidates and sulfamides by rhodium-catalyzed arylation of cyclic ketimines.

    PubMed

    Nishimura, Takahiro; Ebe, Yusuke; Fujimoto, Hiroto; Hayashi, Tamio

    2013-06-18

    Asymmetric addition of arylboronates to aryl-substituted cyclic ketimines proceeded in the presence of a rhodium catalyst coordinated with a chiral diene ligand to give high yields of sulfamidates and sulfamides with high enantioselectivity (up to 99% ee).

  9. The effect of cyclic AMP and cyclic GMP phosphodiesterase inhibitors on the superoxide burst of guinea-pig peritoneal macrophages.

    PubMed Central

    Turner, N. C.; Wood, L. J.; Burns, F. M.; Gueremy, T.; Souness, J. E.

    1993-01-01

    1. The cyclic nucleotide phosphodiesterase (PDE) activity of guinea-pig peritoneal macrophages was partially characterized and the effects of selective and non-selective inhibitors of adenosine 3':5'-cyclic monophosphate (cyclic AMP PDE) and guanosine 3':5'-cyclic monophosphate (cyclic GMP PDE) phosphodiesterases on superoxide generation were investigated using peritoneal macrophages from horse-serum pretreated guinea-pigs. 2. The non-selective PDE inhibitor, 3-isobutyl-1-methylxanthine (IBMX) and the PDE I/V selective inhibitor, zaprinast, inhibited spontaneous superoxide generation with IC50s of 30.7 +/- 11.3 microM and 145 +/- 17 microM respectively (n = 6 and 5). The concentration-response curves for the PDE IV selective inhibitors rolipram and Ro20-1724 were biphasic; mean maximum inhibitions were 56.9 +/- 5.9% and 66.8 +/- 10.5% respectively at 300 microM, but in 2 out of 6 (rolipram) and 2 out of 5 (Ro20-1724) experiments inhibition was < 50%. The PDE III inhibitor SK&F 94120 was without effect. Spontaneous superoxide generation was reduced 57 +/- 10% by 1 microM prostaglandin E2 (PGE2) and 62.6 +/- 3.76% by 1 microM salbutamol. 3. The increase in superoxide generation elicited by FMLP (10(-9)-10(-5)M) was unaffected by any of the PDE inhibitors studied. Inhibition of FMLP-stimulated superoxide generation by PGE2 was enhanced in the presence of 10 microM IBMX. 4. Macrophages were found to contain a predominantly membrane bound cyclic AMP PDE (90% of total activity) which was unaffected by cyclic GMP or calcium/calmodulin. The cyclic AMP PDE activity in the cytosolic fraction was enhanced in the presence of calcium/calmodulin.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8387385

  10. The Labelling Approach to Deviance.

    ERIC Educational Resources Information Center

    Rains, Prudence M.; Kitsuse, John L.; Duster, Troy; Freidson, Eliot

    2003-01-01

    This reprint of one chapter from the 1975 text, "Issues in the Classification of Children" by Nicholas Hobbs and others, addresses the theoretical, methodological, and empirical issues involved in the "labeling" approach to the sociology of deviance. It examines the social process of classification, the use of classification in social agencies,…

  11. When Diagnostic Labels Mask Trauma

    ERIC Educational Resources Information Center

    Foltz, Robert; Dang, Sidney; Daniels, Brian; Doyle, Hillary; McFee, Scott; Quisenberry, Carolyn

    2013-01-01

    A growing body of research shows that many seriously troubled children and adolescents are reacting to adverse life experiences. Yet traditional diagnostic labels are based on checklists of surface symptoms. Distracted by disruptive behavior, the common response is to medicate, punish, or exclude rather than respond to needs of youth who have…

  12. How to read food labels

    MedlinePlus

    ... 24 liters) cooked. If you eat 2 cups (0.48 liters) at a meal, you are eating 2 servings. That is 2 times the amount of the calories, fats, and other items listed on the label. Calorie information tells you the number of calories in ...

  13. Revisiting Labels: "Hearing" or Not?

    ERIC Educational Resources Information Center

    Rhoades, Ellen A.

    2010-01-01

    This position paper briefly presents evidence-based findings pertaining to the language of labels for people with hearing loss that relate to stigma, expectation levels, stereotypes, and self-fulfilling prophecies. These constructs are important for auditory-based practitioners, administrators, policymakers, students, families, and persons with…

  14. The Labelling Approach to Deviance.

    ERIC Educational Resources Information Center

    Rains, Prudence M.; Kitsuse, John L.; Duster, Troy; Freidson, Eliot

    2003-01-01

    This reprint of one chapter from the 1975 text, "Issues in the Classification of Children" by Nicholas Hobbs and others, addresses the theoretical, methodological, and empirical issues involved in the "labeling" approach to the sociology of deviance. It examines the social process of classification, the use of classification in social agencies,…

  15. When Diagnostic Labels Mask Trauma

    ERIC Educational Resources Information Center

    Foltz, Robert; Dang, Sidney; Daniels, Brian; Doyle, Hillary; McFee, Scott; Quisenberry, Carolyn

    2013-01-01

    A growing body of research shows that many seriously troubled children and adolescents are reacting to adverse life experiences. Yet traditional diagnostic labels are based on checklists of surface symptoms. Distracted by disruptive behavior, the common response is to medicate, punish, or exclude rather than respond to needs of youth who have…

  16. Revisiting Labels: "Hearing" or Not?

    ERIC Educational Resources Information Center

    Rhoades, Ellen A.

    2010-01-01

    This position paper briefly presents evidence-based findings pertaining to the language of labels for people with hearing loss that relate to stigma, expectation levels, stereotypes, and self-fulfilling prophecies. These constructs are important for auditory-based practitioners, administrators, policymakers, students, families, and persons with…

  17. Psychological effectiveness of carbon labelling

    NASA Astrophysics Data System (ADS)

    Beattie, Geoffrey

    2012-04-01

    Despite the decision by supermarket-giant Tesco to delay its plan to add carbon-footprint information onto all of its 70,000 products, carbon labelling, if carefully designed, could yet change consumer behaviour. However, it requires a new type of thinking about consumers and much additional work.

  18. Radiolabeling of a cyclic RGD (cyclo Arg-Gly-Asp-d-Tyr-Lys) peptide using sodium hypochlorite as an oxidizing agent.

    PubMed

    Doll, Stephanie; Woolum, Karen; Kumar, Krishan

    2016-09-01

    A simple and rapid nonradioactive iodide labeling/radiolabeling method for peptides, using an inexpensive oxidizing agent such as sodium hypochlorite and a cyclic peptide, cRGDyK (cyclo Arg-Gly-Asp-d-Tyr-Lys), was developed in this work. Labeling reaction was optimized by conducting experiments under variable ratios of the reagents, the reaction times, and the pH. The study demonstrated that radiolabeling of the cyclic peptide was fast and pH independent. Monoiodinated and di-iodinated cRGDyK were formed under all conditions and varied with the ratio of the reagents and the reaction time. Total percent of the iodinated cRGDyK (monoiodinated and di-iodinated cRGDyK) varied between 44 and 100 depending on the reaction conditions. Excess cyclic peptide over equal molar ratio of sodium iodide and sodium hypochlorite yielded in predominant amounts of monoiodinated cRGDyK, ie, >60% under 2:1:1 ratio and ~88% under 5:1:1 ratio of cRGDyK:sodium iodide:sodium hypochlorite.

  19. The role of cyclic nucleotide signaling pathways in cancer: targets for prevention and treatment.

    PubMed

    Fajardo, Alexandra M; Piazza, Gary A; Tinsley, Heather N

    2014-02-26

    For more than four decades, the cyclic nucleotides cyclic AMP (cAMP) and cyclic GMP (cGMP) have been recognized as important signaling molecules within cells. Under normal physiological conditions, cyclic nucleotides regulate a myriad of biological processes such as cell growth and adhesion, energy homeostasis, neuronal signaling, and muscle relaxation. In addition, altered cyclic nucleotide signaling has been observed in a number of pathophysiological conditions, including cancer. While the distinct molecular alterations responsible for these effects vary depending on the specific cancer type, several studies have demonstrated that activation of cyclic nucleotide signaling through one of three mechanisms-induction of cyclic nucleotide synthesis, inhibition of cyclic nucleotide degradation, or activation of cyclic nucleotide receptors-is sufficient to inhibit proliferation and activate apoptosis in many types of cancer cells. These findings suggest that targeting cyclic nucleotide signaling can provide a strategy for the discovery of novel agents for the prevention and/or treatment of selected cancers.

  20. The Role of Cyclic Nucleotide Signaling Pathways in Cancer: Targets for Prevention and Treatment

    PubMed Central

    Fajardo, Alexandra M.; Piazza, Gary A.; Tinsley, Heather N.

    2014-01-01

    For more than four decades, the cyclic nucleotides cyclic AMP (cAMP) and cyclic GMP (cGMP) have been recognized as important signaling molecules within cells. Under normal physiological conditions, cyclic nucleotides regulate a myriad of biological processes such as cell growth and adhesion, energy homeostasis, neuronal signaling, and muscle relaxation. In addition, altered cyclic nucleotide signaling has been observed in a number of pathophysiological conditions, including cancer. While the distinct molecular alterations responsible for these effects vary depending on the specific cancer type, several studies have demonstrated that activation of cyclic nucleotide signaling through one of three mechanisms—induction of cyclic nucleotide synthesis, inhibition of cyclic nucleotide degradation, or activation of cyclic nucleotide receptors—is sufficient to inhibit proliferation and activate apoptosis in many types of cancer cells. These findings suggest that targeting cyclic nucleotide signaling can provide a strategy for the discovery of novel agents for the prevention and/or treatment of selected cancers. PMID:24577242