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Contant observation

Jacinthe Contant, Frances R Pick
Although picophytoplankton (PP) (0.2-2 µm) are ubiquitous in lakes and oceans, their importance in rivers has rarely been studied. We examined PP assemblages during the ice-free period in five rivers of a temperate region varying in trophic state (9-107 µg/L total phosphorus) and water discharge (1-87 m(3)/s). In these rivers, PP abundance reached concentrations as high as those observed in lakes and oceans (∼10(4)-10(5) cells/mL). The highest density of PP (4.9 × 10(5) cells/mL) was observed in the most eutrophic river when the water temperature (28°C) and total phosphorus (293 µg/L) were highest...
May 2013: Journal of Plankton Research
Reza Kermani, Joseph J Coury, Haisar Dao, Justin H Lee, Peter E Miller, Darrick Yee, Charles Contant, Alan W Hackford
BACKGROUND: Critically ill patients requiring emergent colectomy have significant mortality risk. OBJECTIVE: A national administrative database was used to compose a simple scoring scheme for predicting in-hospital mortality risk. DESIGN: The 2007 to 2009 Nationwide Inpatient Sample was queried to identify patients requiring nonelective colectomy. Multivariable binary logistic regression analysis was used to identify predictors that increased mortality...
April 2013: Diseases of the Colon and Rectum
Meyer Michel Samama, Genevieve Contant, Theodore E Spiro, Elisabeth Perzborn, Lena Le Flem, Céline Guinet, Yves Gourmelin, Jean Luc Martinoli
This study evaluated the prothrombin time (PT) assay for the measurement of plasma concentrations of rivaroxaban using calibrators and controls. The intra- and interlaboratory precision of the measurement was investigated in a field trial involving 21 laboratories. Each laboratory was provided with rivaroxaban calibrators and control plasma samples containing different concentrations of rivaroxaban, and PT reagents. The evaluation was carried out over 2 consecutive weeks using centrally provided and local PT reagents...
March 2012: Clinical and Applied Thrombosis/hemostasis
Meyer Michel Samama, Genevieve Contant, Theodore E Spiro, Elisabeth Perzborn, Céline Guinet, Yves Gourmelin, Léna Le Flem, Gabriele Rohde, Jean Luc Martinoli
Rivaroxaban is an oral, direct factor Xa inhibitor. Routine coagulation monitoring is not required, but a quantitative determination of rivaroxaban concentrations might be useful in some clinical circumstances. This multicentre study assessed the suitability of the anti-factor Xa chromogenic assay for the measurement of rivaroxaban plasma concentrations (ng/ml) using rivaroxaban calibrators and controls, and the inter-laboratory precision of the measurement. Twenty-four centres in Europe and North America were provided with sets of rivaroxaban calibrators (0, 41, 209 and 422 ng/ml) and a set of rivaroxaban pooled human plasma controls (20, 199 and 662 ng/ml; the concentrations were unknown to the participating laboratories)...
February 2012: Thrombosis and Haemostasis
Fu-Qiang Zhang, Wei Guan, Li-Kan Yan, Yin-Tang Zhang, Mao-Tian Xu, Ebenezer Hayfron-Benjamin, Zhong-Min Su
Density functional theory calculations have been carried out to investigate α-, β-, γ-, α*-, β*-, and γ*-[(PO(4))(2)W(18)O(54)](6-) Wells-Dawson isomers, which exhibited stability in the order of α > β > γ > γ* > β* > α*, reproduced the experimental observations (α > β > γ), and confirmed the hypothesis of Contant and Thouvenot (γ* > β* > α*). Energy decomposition analysis reveals that both the spatial arrangement of the host W(18)O(54) cage (eclipsed or staggered) and its structural distortion induced by the encapsulated guest anions are two dominant factors in control of the stability order, while the influences of host-guest interaction and distortion of the guest anions are very small...
June 6, 2011: Inorganic Chemistry
Michelle L O'Donoghue, Deepak L Bhatt, Stephen D Wiviott, Shaun G Goodman, Desmond J Fitzgerald, Dominick J Angiolillo, Shinya Goto, Gilles Montalescot, Uwe Zeymer, Philip E Aylward, Victor Guetta, Dariusz Dudek, Rafal Ziecina, Charles F Contant, Marcus D Flather et al.
BACKGROUND: Atopaxar (E5555) is a reversible protease-activated receptor-1 thrombin receptor antagonist that interferes with platelet signaling. The primary objective of the Lessons From Antagonizing the Cellular Effects of Thrombin-Acute Coronary Syndromes (LANCELOT—ACS) trial was to evaluate the safety and tolerability of atopaxar in patients with ACS. METHODS AND RESULTS: Six hundred and three subjects were randomized within 72 hours of non-ST-elevation ACS to 1 of 3 doses of atopaxar (400-mg loading dose followed by 50, 100, or 200 mg daily) or matching placebo...
May 3, 2011: Circulation
Stephen D Wiviott, Marcus D Flather, Michelle L O'Donoghue, Shinya Goto, Desmond J Fitzgerald, Fernando Cura, Philip Aylward, Victor Guetta, Dariusz Dudek, Charles F Contant, Dominick J Angiolillo, Deepak L Bhatt et al.
BACKGROUND: Thrombin is a key mediator of platelet activation. Atopaxar is a reversible protease-activated receptor-1 antagonist that interferes with thrombin-mediated platelet effects. The phase II Lessons From Antagonizing the Cellular Effect of Thrombin-Coronary Artery Disease (LANCELOT-CAD) trial examined the safety and tolerability of prolonged therapy with atopaxar in subjects with CAD. METHODS AND RESULTS: Subjects with a qualifying history were randomized in a double-blind fashion to 3 dosing regimens of atopaxar (50, 100, or 200 mg daily) or matching placebo for 24 weeks and followed up for an additional 4 weeks...
May 3, 2011: Circulation
Steven G Terra, Omar L Francone, Charles F Contant, Xiang Gao, Andrew J Lewin, Tu T Nguyen
The weak peroxisome proliferator activated receptor-alpha (PPAR-alpha) agonists gemfibrozil and fenofibrate achieve only small increases in high-density lipoprotein (HDL) cholesterol. CP-778,875 is a more potent PPAR-alpha agonist developed to produce greater HDL cholesterol increases. This randomized, multicenter, double-blinded, placebo-controlled study evaluated the efficacy and safety of CP-778,875 in subjects with mixed dyslipidemia and type 2 diabetes. Eight-six subjects with low HDL cholesterol (< or =45 mg/dl for men and < or =55 mg/dl for women) and increased triglycerides (150 to 500 mg/dl) who had coexisting type 2 diabetes were randomized...
August 15, 2008: American Journal of Cardiology
Bineta Keita, Essadik Abdeljalil, Louis Nadjo, Roland Contant, Robila Belghiche
Electrochemical behaviors of selected Dawson-type polytungstates including 2-K10[P2W15Mo2O61box] where the symbol [box] designates a vacant site, alpha2-K7[Fe(OH2)P2W15Mo2O61], alpha2-K8[Cu(OH2)P2W15Mo2O61], alpha1- and alpha2-K8[Cu(OH2)P2W17O61], alpha2-K8[Cu(OH2)P2W13Mo4O61], and alpha2-K8[Cu(OH2)P2W12Mo5O61] were investigated by cyclic voltammetry (CV) coupled with the electrochemical quartz microbalance (EQCM), and the results were completed by atomic force microscopy (AFM) observations of the electrodeposited films...
December 5, 2006: Langmuir: the ACS Journal of Surfaces and Colloids
Changlong Jiang, Wangqun Zhang, Guifu Zou, Weicao Yu, Yitai Qian
Flowerlike cupped-end ZnO microrod bundles have been hydrothermally synthesized from precursor ZnCl2(N2H4)2 in sheet shape at 140 degrees C for 12 h; under the same conditions using the same precursor in rod shape, uniform ZnO nanorods were obtained. XRD pattern indicated the sample is ZnO with hexagonal cell contants a = 3.251 A and c = 5.206 A. FE-SEM and TEM show the formation process of the ZnO sample. HRTEM revealed that the flowerlike cupped-end ZnO microrod bundles grow along the [101] axis. The UV emission peak at approximately 396 nm and the blue band emission peak at approximately 469 nm were observed by PL spectra...
February 3, 2005: Journal of Physical Chemistry. B
Nebebech Belai, Michael H Dickman, Michael T Pope, Roland Contant, Bineta Keita, Israel-Martyr Mbomekalle, Louis Nadjo
Reaction of Ce(III) with lacunary versions of [H(4)XW(18)O(62)](7-) (X = P, As) yields the 1:2 complexes [Ce(H(4)XW(17)O(61)](19-) (X = As, 1; P, 2) in good yield, characterized in solution and the solid state by NMR spectroscopy and X-ray crystallographic analysis, respectively. The structures confirm a syn C(2) conformation that is analogous to that observed for [Ln(alpha(2)-P(2)W(17)O(61))(2)](17-) but with "empty" O(4) tetrahedra that are in positions remote from the cerium atom. Bond valence sum calculations for these structures show that the four protons that are required for charge balance in all salts of the XW(18) anions and their lacunary derivatives are almost certainly bound to the oxygen atoms of the empty tetrahedra...
January 24, 2005: Inorganic Chemistry
Roman Hlatky, Alex B Valadka, J Clay Goodman, Charles F Contant, Claudia S Robertson
The purpose of this study was to examine the patterns of change in microdialysate concentrations of glucose, lactate, pyruvate, and glutamate in the brain during periods of hypoxia/ischemia identified by monitoring brain tissue pO2 (PbtO2). Of particular interest was a better understanding of what additional information could be obtained by the microdialysis parameters that was not available from the PbtO2. Fifty-seven patients admitted with severe traumatic brain injury who had placement of both a brain tissue pO2 (PbtO2) and microdialysis probe were studied...
July 2004: Journal of Neurotrauma
Jennifer van Wijngaarden, Wolfgang Jäger
Microwave rotational spectra of eleven isotopomers of the Ne(3)-NH(3) van der Waals tetramer were measured using a pulsed jet, Balle-Flygare type Fourier transform microwave spectrometer. The transitions measured fall between 4 and 17 GHz and correspond to the ground internal rotor state of the weakly bound complex. The (20)Ne(3)- and (22)Ne(3)-containing species are symmetric top molecules while the mixed (20)Ne(2)(22)Ne- and (20)Ne(22)Ne(2)-isotopomers are asymmetric tops. For each of the deuterium-containing isotopomers, a tunneling splitting was observed due to the inversion of NH(3) within the tetramer...
November 26, 2003: Journal of the American Chemical Society
Brooks J Hornstein, Richard G Finke
A reliable way to determine the purity of the kinetically precipitated, noncrystalline lacunary polyoxoanion alpha-P(2)W(15)O(56)(12-) has been developed, namely, the conversion of alpha-P(2)W(15)O(56)(12-) into the tri-Nb(5+)- and V(5+)-containing polyoxoanions P(2)W(15)Nb(3)O(62)(9-) and P(2)W(15)V(3)O(62)(9-), respectively, followed by quantitative analysis of their purity by (31)P-NMR prior to recrystallization. With this previously unappreciated, straightforward alpha-P(2)W(15)O(56)(12-) purity-assessment methodology in hand, the five reported literature syntheses of alpha-P(2)W(15)O(56)(12-) are investigated with an emphasis on understanding the effects of the five differing variables within these syntheses (the amount of Na(2)CO(3) base, the rate of addition of the base, the reaction temperature, the reaction scale, and the product drying method)...
May 20, 2002: Inorganic Chemistry
F Forestier, S Bélisle, C Contant, F Harel, G Janvier, J F Hardy
PURPOSE: Despite their common use in cardiac surgery, few studies have evaluated the reproducibility of the Thromboelastograph (TEG), of the Sonoclot (SCT), and of the activated coagulation time with celite (ACT-C) or kaolin (ACT-K) measured with the Hemochron, in clinical conditions of on-site monitoring of hemostasis. This study determined the reproducibility of those measurements, and evaluated the ability of various devices to substitute for the ACT-C. METHODS: Blood samples collected from 20 volunteers and 21 patients undergoing myocardial revascularization were analyzed in the two channels of the TEG, in two SCT and four Hemochron analyzers...
October 2001: Canadian Journal of Anaesthesia, Journal Canadien D'anesthésie
C F Contant, A B Valadka, S P Gopinath, H J Hannay, C S Robertson
OBJECT: The factors involved in the development of adult respiratory distress syndrome (ARDS) after severe head injury were studied. The presence of ARDS complicates the treatment of patients with severe head injury, both because hypoxia causes additional injury to the brain and because therapies that are used to protect the lungs and improve oxygenation in patients with ARDS can reduce cerebral blood flow (CBF) and increase intracranial pressure (ICP). In a recent randomized trial of two head-injury management strategies (ICP-targeted and CBF-targeted), a fivefold increase in the incidence of ARDS was observed in the CBF-targeted group...
October 2001: Journal of Neurosurgery
C A Muszynski, L A Hayman, K Weingarten, H W Prow, J W Cole, C F Contant
Our purpose was to assess the role of serial CT in recently traumatized patients with clinically stable extra-axial intracranial hematomas (EACH) and a midline shift of less than 0.5 cm. A retrospective review of 91 imaging studies in 41 patients (with 45 EACH) was done to assess the time between trauma and CT; the presence and type of skull fracture; the volume, type, and location of the EACH; the presence of associated edema and/or contusion. Over a 19-day follow-up, 11% of the dense EACH increased in volume and 27% decreased...
December 1999: Neuroradiology
Gopinath, Valadka, Contant, Robertson
OBJECTIVE: The goal of this study was to analyze the use of thermal diffusion-cerebral blood flow (TD-CBF) monitoring as a continuous monitoring method for patients with head injuries in the intensive care unit. METHODS: The TD-CBF probe was placed on normal-appearing frontal or parietal cortex at the time of surgery to treat traumatic intracranial hematomas in 35 patients, and cortical cerebral blood flow (CBF) was monitored for up to 7 days after surgery. We compared TD-CBF values with global CBF values measured by the standard Kety-Schmidt technique, and we compared changes in TD-CBF with changes in jugular venous oxygen saturation observed during intracranial pressure elevations...
June 1999: Neurosurgery
G Degrassi, B C Okeke, C V Bruschi, V Venturi
Bacillus pumilus PS213 was found to be able to release acetate from acetylated xylan. The enzyme catalyzing this reaction has been purified to homogeneity and characterized. The enzyme was secreted, and its production was induced by corncob powder and xylan. Its molecular mass, as determined by gel filtration, is 190 kDa, while sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a single band of 40 kDa. The isoelectric point was found to be 4.8, and the enzyme activity was optimal at 55 degrees C and pH 8...
February 1998: Applied and Environmental Microbiology
X Tong, D G Engehausen, C T Freund, I Agoulnik, M K Oehler, T E Kim, A Hasenburg, Z Guo, C F Contant, S L Woo, D G Kieback
The cytomegalovirus (CMV) promoter is considered one of the strongest positive regulators leading to expression of higher levels of the thymidine kinase (TK) enzyme than the Rous Sarcoma virus (RSV) promoter in vitro and in vivo. Cell killing efficacy of adenovirus-mediated CMV promoter-driven herpes simplex virus (HSV) TK gene therapy has been found to be 2 to 10 times more effective than RSV driven HSV-TK gene therapy in vitro. In this study the impact of CMV- versus RSV-driven HSV-TK gene therapy on long-term survival of nude mice bearing human ovarian cancer has been evaluated using a prospective randomized experimental design...
February 1999: Hybridoma
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