Showing papers by "Université de Sherbrooke published in 1977"
TL;DR: In this article, the influence of material strain-rate dependence on necking retardation is studied and a nonlinear analysis for long-wavelength nonuniformities does reproduce the essential details of the phenomenon.
358 citations
90 citations
TL;DR: Structural differences between wt and ts1 cores are established, most important the differential affinity of precursor polypeptides for DNA in ts1 virions under different conditions of disintegration, suggesting the loss of infectivity by the mutant is due to the altered composition and structure of the viral core.
85 citations
TL;DR: Age‐sex specific reference values and frequency distribution of erythrocyte parameters were derived from a representative sample of a natural population unselected as to disease and are presented as percentile distributions by age and sex rather than as the more frequently used normal distribution.
Abstract: Age-sex specific reference values and frequency distribution of erythrocyte parameters were derived from a representative sample of a natural population consisting of 1094 men and 1284 women between 10 and 96 years of age. Some differences have been found between previously reported reference values and those presented here, the importance of which lies not so much in their magnitude as in the fact that the latter are based upon a probability sample of a natural population unselected as to disease and are presented as percentile distributions by age and sex rather than as the more frequently used normal distribution. These results are intended for use as reference data both for clinical and for population estimates of haematological parameters.
80 citations
TL;DR: The linkage of the [32P](ADP-Rib) residues to each protein was very labile at pH values greater than 7.0 but by working at acidic pH and low temperatures the ADP- Rib label could be shown to be covalently bound to protein by gel electrophoresis and ion-exchange chromatography.
Abstract: Isolated trout testis nuclei rapidly incorporate [alpha-32P]NAD+ into chromosomal proteins. Three proteins, very-lysine-rich histone (H1), a specific trout chromosomal protein (H6) and the sperm-specific protamines, incorporate the label as adenosine diphosphoribosyl (ADP-Rib) residues. No significant labeling of the nucleosomal 'core' histones H2A, H2B, H3 and H4 was observed. The linkage of the [32P](ADP-Rib) residues to each protein was very labile at pH values greater than 7.0 but by working at acidic pH and low temperatures the ADP-Rib label could be shown to be covalently bound to protein by gel electrophoresis and ion-exchange chromatography. The [32P]ADP-Rib chains could be removed by digestion with snake venom phosphodiesterase with the formation of AMP and phosphoribosyl-AMP.
77 citations
TL;DR: In this article, the dispersion related for the conduction band has been obtained along with a ${\ensuremath{\Gamma}}_{8}$ energy gap of 0.19 eV.
Abstract: Electron effective-mass values obtained from room-temperature magneto-Seebeck and Hall measurements on ${\mathrm{Cd}}_{3}$${\mathrm{As}}_{2}$ have been gathered from the literature. Using Kane's model for an $\ensuremath{\alpha}\ensuremath{-}\mathrm{Sn}$-type inverted electronic energy band structure, the dispersion related for the conduction band has been obtained along with a ${\ensuremath{\Gamma}}_{8}\ensuremath{-}{\ensuremath{\Gamma}}_{6}$ energy gap of 0.19 eV. Combining these results with the available room-temperature optical data, the relative positions of other bands have been obtained. The heavy-hole valence band, whose maximum is displaced from $\ensuremath{\Gamma}$ by \ensuremath{\sim} 10% of the distance to the Brillouin-zone edge, has a possible small overlap with the conduction band. These two ${\ensuremath{\Gamma}}_{8}$ bands are split at $\ensuremath{\Gamma}$ by a residual gap of \ensuremath{\sim} 0.04 eV. There is a second conduction band whose minimum at $\ensuremath{\Gamma}$ is \ensuremath{\sim} 0.6 eV above the ${\ensuremath{\Gamma}}_{8}$ valence band and perhaps a third one \ensuremath{\sim} 0.4 eV above the latter.
61 citations
TL;DR: In this article, the spectral changes induced by various non-electrolytes (1.0m) on the 1000 nm band have been recorded at 25°C for the following: tetrahydrofuran, tetrahedropyran, dioxane, dimethoxyethane, Dimethyl sulfoxide, acetone, methyl acetate, propylene carbonate, dimethylformamide and dimethylacetamide, tetramethylurea, acetonitrile, and nitromethane.
Abstract: The differential infrared absorption spectra of H2O at 1200 nm and HOD/D2O at 1450 nm have been recorded as function of temperature between 2 and 55°C. Following earlier investigations in the 1000 nm region,(1,2) the data were interpreted on the basis of a hydrogen-bonding equilibrium invoking two states of the OH oscillators which are found to differ by a van't Hoff heat of formation of 2–3 kcal-mole−1. The spectral changes induced by various non-electrolytes (1.0m) on the 1000 nm band have been recorded at 25°C for the following: tetrahydrofuran, tetrahydropyran, dioxane, dimethoxyethane, dimethyl sulfoxide, acetone, methyl acetate, propylene carbonate, dimethylformamide, dimethylacetamide, tetramethylurea, acetonitrile, and nitromethane. The specific influence of hydrocarbon chains on the near-IR absorption spectrum of water was further studied using a series of homologous sodiumn-alkyl carboxylates (formate to octanoate). The differential solvation spectra of three azoniaspiroalkane bromides have been obtained to compare the relative effects of cyclic and linear alkyl substituents. Finally, the study of ionic hydration effects has been extended to include the following electrolytes: NaPF6, NaClO4, NaBF4, NaClO3, NaNO3, NaBrO3, NaCN, NaSCN, Na2SO4, Na2SO3, Na2CO3, Na2S2O3, MgCl2, CaCl2, BaCl2, and SrCl2. These data are discussed in terms of perturbations of the hydrogen-bonding equilibrium in water originating from one of the following: (1) direct OH... [polar group or anion] interactions, (2) structure-breaking effects due to weak OH... solute interactions, and (3) water-structure-promoting effects by alkyl groups.
51 citations
TL;DR: The results indicate that the exocrine pancreas acquired a responsiveness to urecholine on the 3rd day of postnatal life and becomes more sensitive to stimulation from the 15th day.
47 citations
TL;DR: In this article, the authors studied the vertical and torsional motions of a suspension bridge due to wind loading and buffeting, independent of bridge motion and wind loads, using aerodynamic coefficient or Duhamel integral formulations.
Abstract: Vertical and torsional motions of a suspension bridge due to wind loading are studied. Both, self-excited, due to bridge motion, and buffeting, independent of bridge motion, wind loads are included. The self-excited aerodynamic forces are modeled using aerodynamic coefficient or Duhamel integral formulations. For this purpose, experimental information on section models from wind tunnel testing is utilized. The buffeting random loads are determined from specified spectral densities or horizontal and vertical turbulent wind velocity fluctuations. Numerical results are obtained using frequency and time domain formulations. Dynamic bridge stability is also investigated.
45 citations
TL;DR: Twelve cases of neonatal intussusception are presented and another 25 taken from the literature are reviewed, and the barium-enema examination is diagnostic.
Abstract: Twelve cases of neonatal intussusception are presented and another 25 taken from the literature are reviewed. Intussusception in the first month of life is a distinct clinical and pathological entity, presenting as bowel obstruction in the first days and usually led by a tumor. In the past, a high mortality rate has been related to late diagnosis. The barium-enema examination is diagnostic.
43 citations
TL;DR: The ionized-impurity mobility of Cd 3 As 2 at 4.2 K with carrier concentration lying in the range 10 18 −10 19 cm −3 has been calculated taking into account the inverted HgTe-type energy band structure of this material.
TL;DR: It was found that chymotrypsinogen, amylase and lipase productions were increased by 63, 26 and 10%, respectively, indicating that repeated cholecystokinin-pancreozymin plus secretin stimulations could induce "adaptation-like" modifications of the pancreatic enzyme content.
TL;DR: Several features of the liquefaction of peat have been brought to light during the course of this investigation as discussed by the authors, including the possibility of converting even weakly humified peat with a relatively high moisture content into a soft bitumen and a small fraction of light oils.
TL;DR: In this article, the dispersion relation for the conduction band has been obtained along with a energy gap of 0.11 eV using Kane's model for an HgTe-type inverted energy-band structure.
Abstract: Electron-effective-mass values obtained from low-temperature Shubnikov-de Haas, magneto-Seebeck, and Hall measurements on ${\mathrm{Cd}}_{3}$${\mathrm{As}}_{2}$ have been gathered from the literature. Using Kane's model for an HgTe-type inverted energy-band structure, the dispersion relation for the conduction band has been obtained along with a ${\ensuremath{\Gamma}}_{8}\ensuremath{-}{\ensuremath{\Gamma}}_{6}$ energy gap of 0.11 eV. The heavy-hole valence band is split from the conduction band at $\ensuremath{\Gamma}$ by a residual gap of \ensuremath{\sim}0.01 eV. There is a second conduction band whose minimum at $\ensuremath{\Gamma}$ is approximately 0.6 eV above the ${\ensuremath{\Gamma}}_{8}$ valence band and perhaps a third one \ensuremath{\sim}0.4 eV above the latter. Theoretical estimates of the variation of the energy gap at $\ensuremath{\Gamma}$ as a function of temperature and pressure are obtained. Those are found to be consistent with our band model as well as with our analysis of existing temperature data ($\frac{\ensuremath{\partial}{E}_{0}}{\ensuremath{\partial}T}\ensuremath{\sim}5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ eV/K) and pressure data ($\frac{\ensuremath{\partial}{E}_{0}}{\ensuremath{\partial}P}\ensuremath{\sim}\ensuremath{-}2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ eV/bar).
TL;DR: Cell clusters derived from ventricles of newborn rats were found to have action potentials insensitive to TTX but which were abolished by 2 mM manganese, suggesting that in these cells pacemaker activity depends on a slow inward current sensitive toManganese.
TL;DR: The results suggest that the pleiotropic effects of the ts3 mutation arrest virus assembly at a corelike structure is likely to be at the permissive temperature.
TL;DR: Centrifugation experiments in CsCl showed that at the nonpermissive temperature (39°) the mutant could produce only top components (TC) and electrophoresis of purified TC showed that the TC of ts4 differ from those of the wild type (wt) only in the slightly higher levels of polypeptides VIII, XI, and XII in the ts4-TC.
TL;DR: The results indicate that some patients who have cancer have abnormal clotting patterns and are often in a potentially hypercoagulable state that is reflected by the thromboplastin generation test, thrombin generation test and high levels of Factor VIII (both VIII-Ag and VIII-C1).
Abstract: Possible increased activation of the coagulation pathway was measured in a group of patients with neoplastic diseases. In addition to standard tests, the thromboplastin generation test, thrombin generation test and immunologic and coagulant activities of both Factor VIII and antithrombin III were utilized in the evaluation. The correlation between immuno-Factor VIII (VIII-Ag) and its clotting activity (VIII-C1) was good (r = 0.83). In contrast, this was not the situation for antithrombin III-Ag and its clotting activity. Thromboplastin generation was accelerated in 60% and thrombin generation was accelerated in 40% of the patients. Fibrinogen was elevated in half the cases: in most of these patients, thrombin times were slightly prolonged. These results indicate that some patients who have cancer have abnormal clotting patterns and are often in a potentially hypercoagulable state that is reflected by the thromboplastin generation test, thrombin generation test, and high levels of Factor VIII (both VIII-Ag and VIII-C1).
TL;DR: The response of the two largest follicles, identified at Day 10 or Day 14 of the estrous cycle in ewe, was determined by injecting exogenous gonadotrophins by determining the proportion of treated and nontreated ewes that ovulated.
Abstract: The fate of the 2 largest follicles (F(1) and F(2)) in 20 crossbred ewes after injection of gonadotropins at 2 stages of the estrous cycle was determined. Follicles were marked with ink at laparotomy (Days 10-14) before injection of some with Vetrophin postoperative estrus. In the 5 ewes laparotomized on Day 10 of the cycle none of the marked follicles ovulated. When gonadotropins were injected 4 of 5 ovulated. When marked on the 14th days of the cycle 4 out of 5 of the ewes ovulated their F(1). In the instance of double ovulation the F(2) was never ovulated. Injection of gonadotropin was ineffective in altering the proportion of F(1) but 50% of the F(2) were ovulated in double ovulation.
TL;DR: In analogy to the mechanism of the photolytic degradation of N-methyl pyridinium chloride, it appears that the (iso)desmosines were degraded via the formation of an open amino aldehyde, which was hydrolysed at acid pH to give free lysine and a substituted glutaconic alde Hyde.
Abstract: It is known that the pyridinium ring of a model compound such as N-methyl pyridinium chloride is cleaved by U.V. radiation at 254 nm. At acid pH the products obtained are methylamine and glutaconaldehyde. Under the same conditions desmosine and isodesmosine are degraded into lysine and probably into the homologous substituted ketone of glutaconaldehyde. At pH 6.0–7.0, a transient open-chain aminoaldehyde intermediate is observed which can either reform the original compound or be cleaved as at low pH. When intact elastin is photolysed for 20 minutes in water, approximately 75% of the (iso) desmosines are destroyed, accompanied by an increase of free lysine residues. No change in the concentration of the other amino acids, including tyrosine, are noted. It is therefore likely that the crosslinks engaged in peptide links are also cleaved photochemically.
TL;DR: It is shown that it is possible to generate a band-limited PSK signal using a ROM and a four-quadrant multiplying D/A Converter.
Abstract: It is shown that it is possible to generate a band-limited PSK signal using a ROM and a four-quadrant multiplying D/A Converter.
TL;DR: A novel class of agents is prepared by coupling steroids with naturally occurring purines and pyrimidines by way of a C–N linkage and may expect their steroid moiety to provide target specificity, while their nucleoside characteristics may result in interference at the DNA level to give the desired anti-tumour activity.
Abstract: THE major classes of anti-cancer chemotherapeutic drugs include alkylating agents, anti-metabolites of nucleic acids, steroid hormones and antibiotics1. Because of the lack of specificity of anti-tumour agents, attempts have been made to increase their specificity and cell-penetrating properties by coupling them to steroid hormones2,3. In particular, steroidal alkylating agents exhibit carcinostatic properties if used in combination with other modes of therapy4. We have prepared a novel class of agents by coupling steroids with naturally occurring purines and pyrimidines by way of a C–N linkage. The structures are unique in that they may be regarded as analogues both of steroid hormones and of ‘nucleosides’ in which the sugar has been replaced. Accordingly, we may expect their steroid moiety to provide target specificity, while their nucleoside characteristics may result in interference at the DNA level to give the desired anti-tumour activity. Preliminary studies on the effect of steroid–nucleosides on the lifespan of tumour-bearing animals show that selectively coupled products exhibit anti-tumour activity.
TL;DR: It is concluded that QNB is 10 times more potent than atropine in inhibiting pancreatic amylase secretion induced by urecholine.
Abstract: 1 Secrection of amylase from rat pancreas stimualted by urecholine was studied in relation to its inhibition by atropine and 3-quinuclidinyl benzilate (QNB). 2 Urecholine-induced secretion was completely abolished by atropine at 10(-6)M and QNB at 10(-8)M. Significant inhibition could be detected at 10(-8)M atropine and 10(-10)M QNB. 3 The secretory response to pancreozymin was not blocked either by atropine or QNB. 4 The inhibitory effect of QNB remained for at least 90 min after its removal from the incubation medium. 5 It is concluded that QNB is 10 times more potent than atropine in inhibiting pancreatic amylase secretion induced by urecholine.
TL;DR: In this paper, the line width and level shift for the ν = 0 level of a harmonic oscillator predissociated by a linear potential were derived for C − and C + curve crossings.
TL;DR: In this article, the results of a measurement of the acoustic phonon dispersion curves in the semiconducting layer structure SnSe2 were presented, and a group-theoretical analysis of the phonon symmetries was given for the major symmetry points in the zone, and the corresponding atomic displacements for the atoms composing a ''layer''.
Abstract: We present the results of a measurement of the acoustic phonon dispersion curves in the semiconducting layer structure SnSe2. The measurements were made at the NRU reactor, Chalk River, by the technique of coherent inelastic neutron scattering. For modes propagating along thec*-direction both the LA and the doubly degenerate TA branches were measured. At the zone boundary the observed frequencies are (1.09±0.04) THz (LA) and (0.71±0.03) THz (TA). For modes propagating along [100] and [110], the LA branch and the TA branch with modes polarized predominantly alongc were measured. A group-theoretical analysis of the phonon symmetries is given for the major symmetry points in the zone, and the corresponding atomic displacements for the atoms composing a «layer» are derived. By assuming rigid layers the results are analysed to obtain a value for the interlayer interaction. This is compared with corresponding values obtained from the acoustic dispersion curves of other layered structures.
TL;DR: The amino acid sequence of the alpha-chain of the major haemoglobin of a newt, T. granulosa, has been determined and it is concluded that the major functional and conformational features ofalpha-chain have been conserved since the divergence of the classes of jawed vertebrates.
Abstract: The amino acid sequence of the IX-chain of the major haemoglobin of a newt, T. granulosa, has been determined. The chain is 142 residues long and has an extra methionine at its N-terminus when compared with human IX-chain. Most of the tryptic peptides were sequenced by a combination of the subtractive Edman method and by deduction from the compositions of overlapping fragments produced by various enzymic treatments. The sequence of two 'core' regions was obtained by automatic sequencing of large peptides produced by trypsin cleavage at arginine residues only after blockage of lysine residues by citraconylation; by cleavage between aspartic acid and proline residues with 70% formic acid, and by cyanogen bromide cleavage at methionine residues.
TL;DR: It is postulated that thedepolarization is due to inhibition of an electrogenic ionic pump, that the changes in APA are due to ionic shifts and depolarization, and that the values of Vmax are largely determined by shifts in the h∞ curve.
TL;DR: On the basis of operational behavioral measurements, it is concluded that the acupuncture procedure — as it was done — did not produce significant changes of pain tolerance in rabbits.
Abstract: We studied the effect of acupuncture stimulation on pain tolerance in rabbits. Painful stimulation was provided by a tungsten lamp focused on the snout. Four acupuncture points were selected: preocular, retroauricular, in the forepaw between the median and ulnar nerves and in the ears. A control series without acupuncture stimulation was also studied. Electrical stimulation was applied bilaterally through the acupuncture needles. A statistical analysis of the reaction time to the noxious stimulus demonstrated that the responses of the acupunctured animals were not significantly different from those of the controls. On the basis of operational behavioral measurements we conclude that the acupuncture procedure — as we did it — did not produce significant changes of pain tolerance in rabbits.
TL;DR: In this article, the g-factor of conduction electrons in Cd3As2 at low temperatures is calculated as a function of carrier concentration, taking into account the inverted HgTe-type energy band structure of this material.
Abstract: Theg-factor of conduction electrons in Cd3As2 at low temperatures is calculated as a function of carrier concentration, taking into account the inverted HgTe-type energy band structure of this material. In as-grown cadmium arsenide with 2×1018 electrons per cm3, the experimental conditions required to observe spin splitting are discussed.