178 research outputs found
Effect of long-term starvation and restricted feeding on growth performance and body composition of juvenile Siberian sturgeon (Acipenser baerii Brandt 1869)
The present study was designed and performed to investigate the eefect of long-term some feeding strategies (starvation, restricted feeding at rate of 1% biomass per tank and satiate feeding as control) on growth performance and body composition of juvenile Siberian sturgeon (Acipenser baerii Brandt 1869) for 8 weeks. In this regard, 270 juveniles Siberian sturgeon (average weight 54 ± 6/27 g and density 1.5 g/l) were distributed in three treatments (with three replicates) in 9 fiberglass tanks (1050 l). For all fish in each tank, body weight and total length were individually recorded at a biweekly interval. At the termination of the experiment period, five fish per replicate were caught randomly for proximate composition. Results showed that growth performance of Siberian sturgeon was affected significantly by starvation and restricted feeding periods. Moisture and lipid contents were differed significantly in all treatments; which the highest moisture and lipid contents were observed in starved and control fish, respectively. Protein content in starved fish was significantly lower than other groups, whereas ash contents were not significantly different among the treatments. In general, weight loss and other growth factors of juveniles siberian sturgeon during the food shortage were refered to mobilizing the body lipid reservesand then body protein sources and replacing with water. In fact, juvenile Siberian sturgeon can conserve body protein stores better than lipids during the food shortage period
catena-Poly[[[aqua(pyrazine-2-carboxamide-κ2 N 1,O)zinc]-μ-pyrazine-2-carboxamide-κ3 N 1,O:N 4] dinitrate]
In the crystal of the title compound, {[Zn(C5H5N3O)2(H2O)](NO3)2}n, the ZnII cation is N,O-chelated by two pyrazine-2-carboxamide (PCA) ligands and is further coordinated by one water molecule and by one pyrazine-N atom from an adjacent PCA ligand in a distorted ZnN3O3 octahedral geometry. One of the two independent PCA ligands bridges two ZnII cations, forming a zigzag polymeric chain running along the c axis. In the crystal, the NO3
− anions link to the chain via O—H⋯O and N—H⋯O hydrogen bonding. Weak intermolecular C—H⋯O interactions also occur
catena-Poly[[diiodidomercury(II)]-μ2-2-aminopyrazine-κ2 N 1:N 4]
In the crystal of the title polymeric compound, [HgI2(C4H5N3)]n, the HgII cation is located on a twofold rotation axis and is coordinated by two I− anions and two 2-aminopyrazine ligands in a distorted HgI2N2 tetrahedral geometry. In the crystal, the 2-aminopyrazine ligand is equally disordered over two positions about an inversion center, and bridges the HgII cations with pyrazine N atoms to form a polymeric chain running along the c axis. In the polymeric chain, the amino groups link to the coordinated I− anions via intermolecular N—H⋯I hydrogen bonds
catena-Poly[[bis(pyridine-3-carboxylic acid-κN)mercury(II)]-di-μ-chlorido]
In the title compound, [HgCl2(C6H5NO2)2]n, the HgII cation is located on an inversion center and is six-coordinated in a distorted octahedral geometry by two N atoms from two pyridine-3-carboxylic acid molecules and four bridging Cl− anions. The bridging function of the Cl− anions leads to polymeric chains running along the a axis. One Hg—Cl bond is much longer than the other. In the crystal, O—H⋯O and weak C—H⋯Cl hydrogen bonds are observed
Dibromidobis(pyrazine-2-carboxamide-κN 4)zinc
The title complex, [ZnBr2(C5H5N3O)2], shows crystallographic mirror symmetry with the Zn atom and the two bromine ligands located on the mirror plane. The Zn atom is four-coordinated in a distorted tetrahedral fashion by two N atoms from two pyrazine-2-carboxamide ligands and two Br atoms. Only one of the amino H atoms is involved in an N—H⋯O hydrogen bond. The crystal packing is further stabilized by weak N—H⋯N and C—H⋯O interactions
Dichloridobis(pyrazine-2-carboxamide-κN 4)zinc(II)
In the crystal of the title compound, [ZnCl2(C5H5N3O)2], the molecule has m symmetry, with the ZnII cation and Cl− anions located on the mirror plane. The ZnII cation is coordinated by two Cl− anions and two pyrazine-2-carboxamide ligands in a distorted ZnCl2N2 tetrahedral geometry. The two pyrazine rings are nearly perpendicular to each other [dihedral angle = 86.61 (10)°]. Intermolecular N—H⋯O and N—H⋯N hydrogen bonds and weak C—H⋯O interactions stabilize the crystal packing
Aqua(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)(nitrato-κO)(nitrato-κ2 O,O′)zinc
In the title compound, [Zn(NO3)2(C12H12N2)(H2O)], the ZnII atom is six-coordinated in a distorted octahedral geometry by two N atoms from a chelating 4,4′-dimethyl-2,2′-bipyridine ligand, one water O atom, one O atom from a monodentate nitrate anion and two O atoms from a chelating nitrate anion. In the crystal, there are aromatic π–π contacts between the pyridine rings [centroid–centroid distances = 3.9577 (13) Å] and intermolecular O—H⋯O and C—H⋯O hydrogen bonds
A novel method for the synthesis of spiroindoline-pyrazolo4',3':5,6] pyrido2,3-dpyrimidinetriones by alum as a reusable catalyst
Synthesis of spiroindoline-pyrazolo4',3':5,6]pyrido2,3-dpyrimidine trione derivatives by a cyclo-condensation reaction of indolin-2-ones, barbituric acids, and 1,3-diphenyl-1H-pyrazol-5-amines with the ionic liquid as an effective green reaction media and in the presence of Alum as a reusable catalyst was reported. Excellent yields of products, green media, use of a reusable catalyst, and short reaction time are the main advantages of this new method. © 2012 HeteroCorporation
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