scholarly journals Binding of a substrate analogue can induce co-operative structure in the plasmin serine-proteinase domain

1993 ◽  
Vol 293 (2) ◽  
pp. 567-572 ◽  
Author(s):  
A J Teuten ◽  
A Cooper ◽  
R A Smith ◽  
C M Dobson
Keyword(s):  
Differential Scanning Calorimetry ◽  
Structural Properties ◽  
Direct Evidence ◽  
Conformational Transition ◽  
Variable Temperature ◽  
Serine Proteinase ◽  
Scanning Calorimetry ◽  
Affinity Label ◽  
Substrate Analogue ◽  
Kringle 5

Human miniplasminogen and miniplasmin were studied by n.m.r. spectroscopy and differential scanning calorimetry (d.s.c.) in order to investigate the structural properties of the serine-proteinase domain. The d.s.c. thermograms of both miniplasminogen and non-inactivated miniplasmin at pH 4.0 can be closely fitted to two transitions, at 62 +/- 2 and 72 +/- 2 degrees C, corresponding to unfolding of the kringle 5 and proteinase domains respectively. No evidence was found, under these conditions, for non-co-operative unfolding of the proteinase domain. On inactivation of miniplasmin with an affinity label, a number of additional resonances arising from residues of the proteinase domain are observed in resolved regions of the n.m.r. spectrum. A combination of variable-temperature n.m.r. and d.s.c. has shown that part of the proteinase domain undergoes a major conformational transition on heating which is distinct from the unfolding of the remainder of the proteinase domain or the kringle 5 domain. This additional transition occurs at a temperature that depends on the nature of the affinity label present and is not observed in the absence of an inactivating agent. These results provide direct evidence for the existence of a region of the proteinase domain which, under these conditions, becomes structured only in the presence of a bound substrate.

Magnetic concentration and polymorphism in di-n-octyl-, di-n-decyl-, and di-n-dodecylphosphinates of copper(II)

1985 ◽  
Vol 63 (5) ◽  
pp. 1111-1117 ◽  
Author(s):  
John S. Haynes ◽  
Katherine W. Oliver ◽  
Robert C. Thompson
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Susceptibility ◽  
Heisenberg Model ◽  
Variable Temperature ◽  
Electronic Spectroscopy ◽  
Chain Structure ◽  
Magnetic Data ◽  
Scanning Calorimetry ◽  
Extended Chain ◽  
Linear Chains

Phosphinates of copper(II) of the type Cu(R2PO2)2 where R is n-octyl, n-decyl, and n-dodecyl have been synthesized and characterized by differential scanning calorimetry, vibrational and electronic spectroscopy, and variable temperature (300 to 4.2 K) magnetic susceptibility studies. Each of these compounds was obtained in distinct α and β structural forms. All materials appear to have the double phosphinate bridged extended chain structure and the magnetic data have been successfully analyzed according to the isotropic Heisenberg model for linear chains. The α forms exhibit antiferromagnetic behaviour with J values of −25, −29, and −29 cm−1 for the octyl, decyl, and dodecyl derivatives respectively. The β forms are ferromagnetic and have corresponding J values of 1.8, 2.1, and 2.3 cm−1 respectively. Magneto-structural correlations in these extended chain coordination polymers are discussed.

Evidence for room temperature mesomorphism in a mixed-valent diruthenium(II,III) quintapalmitoleate polymer

1998 ◽  
Vol 76 (11) ◽  
pp. 1520-1523
Author(s):  
Jennifer F Caplan ◽  
Christopher A Murphy ◽  
Susan Swansburg ◽  
Robert P Lemieux ◽  
T Stanley Cameron ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Powder Diffraction ◽  
Strong Evidence ◽  
Room Temperature ◽  
Variable Temperature ◽  
Mixed Valence ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystal Transition

The synthesis of Ru2(μ-O2CR)4(μ´-O2CR) (1), R = -CH2(CH2)6CH=CH(CH2)5CH3, has been achieved and characterization using elemental analysis and FTIR and UV-Vis spectroscopies undertaken. Strong evidence for a hexagonal discotic mesophase has been found using differential scanning calorimetry, variable-temperature polarizing optical microscopy, and X-ray powder diffraction. A solid to liquid crystal transition was found upon heating at 128°C and the mesophase is found to persist to room temperature upon cooling from 150°C. This is the first report of room temperature mesomorphism in a mixed-valent metallomesogen. Key words: ruthenium carboxylate, liquid crystal, metallomesogen, mixed valence, polymer.

Thermodynamic and Structural Properties of Mev Ion Beam Amorphized Silicon

1989 ◽  
Vol 157 ◽  
Author(s):  
S. Roorda ◽  
W.C. Sinke ◽  
J.M. Poate ◽  
D.C. Jacobson ◽  
P. Fuoss ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Structural Properties ◽  
Atomic Structure ◽  
Structural Relaxation ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Amorphous Si

ABSTRACTThermodynamic and structural properties of amorphous Si (a-Si), prepared by MeV 28Si+-ion implantation are investigated by differential scanning calorimetry, Raman spectroscopy and X-ray diffraction. The influence of thermal annealing below 500 °C on a-Si is investigated with these different probes. The observed changes result from structural relaxation. Raman spectroscopy and X-ray diffraction show that structural relaxation is accompanied by changes in the average atomic structure.

scholarly journals Synthesis of Thermochromic W-Doped VO2(M/R) Nanopowders by a Simple Solution-Based Process

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Lihua Chen ◽  
Chunming Huang ◽  
Gang Xu ◽  
Lei Miao ◽  
Jifu Shi ◽  
...  
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Transition Temperature ◽  
Structural Properties ◽  
Valence State ◽  
Simple Solution ◽  
Tungsten Content ◽  
Scanning Calorimetry ◽  
First Time ◽  
W Doping

Thermochromic W-doped VO2nanopowders were prepared by a novel and simple solution-based method and characterized by a variety of techniques. We mainly investigated the effect of tungsten dopant on the structural properties and phase transition ofV1-xWxO2. The as-obtained nanopowders with tungsten content of ≤2.5 at% can be readily indexed as monoclinic VO2(M) while that of 3 at% assigned into the rutile VO2(R). The valence state of tungsten in the nanopowders is +6. TEM and XRD results show that the substitution of W atom for V in VO2results in a decrease of thedspace of the (011) plane. The phase transition temperature is determined by differential scanning calorimetry (DSC). It is found, for the first time, that the reduction of transition temperature reaches to 17 K per 1 at% of W doping with the tungsten extents of ≤1 at%, but only 9.5 K per 1 at% with the tungsten extents of >1 at%. The reason of this arises from the difficulty of the formation ofV3+-W4+andV3+-W6+pairs by the increasing of W ions doping in theV1-xWxO2system.

scholarly journals Novel Series of 1,3,4- Oxadiazole Derivatives: Evaluation of Thermal Properties and Antibacterial Activity

2021 ◽  
Vol 10 (3) ◽  
pp. 2370-2381
Keyword(s):  
Differential Scanning Calorimetry ◽  
Antibacterial Activity ◽  
Thermal Properties ◽  
Variable Temperature ◽  
Isotropic Phase ◽  
Aliphatic Acid ◽  
Scanning Calorimetry ◽  
Good Antibacterial Activity ◽  
Oxadiazole Derivatives ◽  
Chloramine T

A new series of 1,3,4-oxadiazole derivatives were synthesized 6(a-i) by the reaction between respective aliphatic acid hydrazides with p-alkoxy aldehydes using chloramine-T (CAT). The synthesized compounds were evaluated for their thermal properties using Polarising Optical Microscopy (POM), Differential Scanning Calorimetry (DSC), and variable temperature Powder X-RD (PXRD). The compounds exhibited spherulitic textures associated with the crystal to isotropic phase. No mesophase was detected upon heating or cooling cycles. Also, the synthesized compounds showed moderate to good antibacterial activity.

Morphology of Polymer-Salt Complex Films Crossover from Fractal to Compact Aggregation

Fractals ◽  
1998 ◽  
Vol 06 (03) ◽  
pp. 285-292 ◽  
Author(s):  
Aninda Jiban Bhattacharyya ◽  
S. Banerjee ◽  
T. R. Middya ◽  
S. Tarafdar
Keyword(s):  
Differential Scanning Calorimetry ◽  
Polyethylene Oxide ◽  
Salt Concentration ◽  
Variable Temperature ◽  
Weight Fraction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
X Ray ◽  
Salt Complex

In this paper we present a study of the variation of morphology of polyethylene oxide (PEO) films complexed with ammonium perchlorate ( NH 4 ClO 4) formed by evaporating a methanolic solution. Films with salt concentration x = 0 - 0.35 (x is the weight fraction of salt) were prepared for the morphology study. The wide varitey of structures obtained were systematically studied by photographs and polarizing microscopy. Some preliminary studies of x-ray diffraction, differential scanning calorimetry and variable temperature polarizing microscopy have also been done to identify the various phases present in the films.

scholarly journals Exceptionally High Temperature Spin Crossover in Amide-Functionalised 2,6-bis(pyrazol-1-yl)pyridine Iron(II) Complex Revealed by Variable Temperature Raman Spectroscopy and Single Crystal X-ray Diffraction.

2021 ◽  
Author(s):  
Max Attwood ◽  
Hiroki Akutsu ◽  
Lee Martin ◽  
Toby J Blundell ◽  
Pierre LeMagueres ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
High Temperature ◽  
Spin Crossover ◽  
Variable Temperature ◽  
Squid Magnetometry ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Complex Salts

The synthesis of a novel amide-functionalised 2,6-bis(pyrazol-1-yl)pyridine-4-carboxamide ligand (bppCONH2) is described. The complex salts [Fe(bppCONH2)2](BF4)2 and [Fe(bppCONH2)2](ClO4)2 were synthesised and characterised by SQUID magnetometry, differential scanning calorimetry, variable temperature Raman...

scholarly journals Synthesis, characterization and initial evaluation of 5-nitro-1-(trifluoromethyl)-3H-1λ3,2-benziodaoxol-3-one

2014 ◽  
Vol 10 ◽  
pp. 1-6 ◽  
Author(s):  
Nico Santschi ◽  
Roman C Sarott ◽  
Elisabeth Otth ◽  
Reinhard Kissner ◽  
Antonio Togni
Keyword(s):  
Differential Scanning Calorimetry ◽  
Cyclic Voltammetry ◽  
Structural Properties ◽  
Kinetic Studies ◽  
Initial Evaluation ◽  
Hypervalent Iodine ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Order Of Magnitude

The synthesis of 5-nitro-1-(trifluoromethyl)-3H-1λ3,2-benziodaoxol-3-one (3), a hypervalent-iodine-based electrophilic trifluoromethylating reagent, is described. Whereas considerations based on cyclic voltammetry and X-ray structural properties would predict an inferior reactivity when compared to the non-nitrated derivative 2, 19F NMR kinetic studies showed that this new derivative is almost one order of magnitude more reactive. Furthermore, differential scanning calorimetry measurements indicated that, in addition, it is also safer to handle.

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