Showing papers by "Université de Sherbrooke published in 1978"
TL;DR: A new method for the determination of inorganic phosphorus released in ATPase assay has been evaluated, based on the reduction of a phosphomolybdate complex by Elon in a copper acetate buffer, which is simple, sensitive, and reproducible.
334 citations
TL;DR: Anorectal myectomy was performed in 62 patients suffering from symptoms attrib¬uted to ineffective colonic motility and one year after myectomy in the 50 patients with less than three stools per week the average number of stoolsper week increased.
324 citations
01 Jan 1978
TL;DR: In this paper, a localization-band bifurcation analysis is carried out and the influence of geometric imperfections is analyzed using the longwavelength approximation treated in Part I. The main emphasis in this Part is on comparisons between the corresponding predictions of flow theory and deformation theory.
Abstract: Various factors affecting the prediction of limit strains in biaxially-stretched sheets are studied. Time-independent material behavior is assumed, and both the flow theory of plasticity as well as a finite-strain version of deformation theory are considered. A localization-band bifurcation analysis is first carried out. The influence of geometric imperfections is then analyzed using the long-wavelength approximation treated in Part I. We also discuss the predicted forming limit curves and comment on their relation to published experimental data. The main emphasis in this Part, however, is on comparisons between the corresponding predictions of flow theory and deformation theory.
234 citations
TL;DR: Evidence of an association between an increased intake of nutrients, especially total fat, in both pre- menopausal and post-menopausal women with breast cancer and its consistency with other evidence, both experimental and international, suggests that it is causal.
Abstract: A case-control study has been conducted in four areas in Canada in which 400 cases of breast cancer matched by age and marital status with neighborhood controls were administered a medical and dietary history questionnaire, a 24-hour recall for dietary information and a four-day diet record. The Study has produced evidence of an association between an increased intake of nutrients, especially total fat, in both pre-menopausal and post-menopausal women with breast cancer. Reasons why a weak association might have been anticipated are discussed, and it is concluded that in reality the association is stronger. Furthermore, its consistency with other evidence, both experimental and international, suggests that it is causal.
233 citations
TL;DR: A case-control study in four areas of Canada is suggestive of an increased risk of breast cancer in post-menopausal women with younger age at menarche and an increase risk with delay of age at natural menopause, and a weak association with increased height and weight as risk factors for breast cancer.
Abstract: A case-control study has been conducted in four areas of Canada in which 400 cases of breast cancer matched by age and marital status with neighborhood controls were administered medical and dietary questionnaires. The study is suggestive of an increased risk of breast cancer in post-menopausal women with younger age at menarche and an increased risk with delay of age at natural menopause. No protective effect of early age at first pregnancy was demonstrated in either pre- or post-menopausal women. An increased frequency of pregnancies of four months duration or less was found in cases compared to controls and a greater frequency in pre-menopausal cases compared to controls of a history of irregular menstrual periods. In pre-menopausal women no association has been found between increased height and weight as risk factors for breast cancer. For post-menopausal women, however, a weak association with increased height has been found, while a strong association with increased weight both at the time of menopause and the 12 months preceding diagnosis has ben confirmed.
201 citations
TL;DR: Three methods of estimating group and individual dietary consumption have been developed and assessed in a case-control study of diet and breast cancer and it is concluded that the diet history is preferred when current food intake may be influenced by a disease.
Abstract: Three methods of estimating group and individual dietary consumption have been developed and assessed in a case-control study of diet and breast cancer. The methods comprised a 24-hour recall, a detailed quantitative diet history directed to the most recent two-month period and the two-month period six months before, and a four-day diet diary. There is a high degree of correlation between the estimates of food consumption for the controls using each of the methods. The highest estimate was obtained from the diet history, with a slightly higher estimate in the period six months before than the current period, while the lowest is found in the 24-hour recall. The latter corresponds with the same method in a Nutrition Canada Survey. It is concluded that all methods ara applicable to case-control studies, but the diet history is preferred when current food intake may be influenced by a disease.
181 citations
TL;DR: The first four members of the 2-nalkoxyethanols were measured in water over the whole mole fraction range with a flow densimeter and a flow microcalorimeter as mentioned in this paper.
Abstract: The densities and heat capacities of the first four members of the 2-n-alkoxyethanols were measured in water over the whole mole fraction range with a flow densimeter and a flow microcalorimeter The methoxy and n-propoxy homologs were studied at 25°C, ethoxyethanol at 19, 25, and 40C, andn-butoxyethanol at 4, 10, 25, 40, and 55°C While methoxyethanol behaves as a fairly typical polar nonelectrolyte in water,n-butoxyethanol shows trends in the concentration dependence which resemble micellization; some pseudo-microphase transition occurs at about 002 mole fraction, and this transition concentration decreases with increasing temperature There is no simple relationship between this phenomenon and the existence of a lower critical solution temperature at 49°C since the sharpness of the thermodynamic changes is maximum at the lowest temperature and at 55°C the apparent molal quantities on both sides of the two-phase region appear to fall on the same continuous curve In the region prior to the pseudo-microphase separation the apparent and partial molal heat capacities decrease regularly but beyond approximately 001 mole fraction increase sharply to a maximum, suggesting some type of pre-association The apparent molal heat capacity of water in the binary solutions is larger than the molar heat capacity of water over the whole mole fraction range The present data seem to be consistent with a clathrate model for hydrophobic hydration and interactions with these systems
148 citations
01 Jan 1978
TL;DR: In this article, the effect of strain-rate dependence on necking retardation was examined for biaxially-stretched sheets, and the influence of strain rate dependence on imperfection sensitivity and forming limit curves was discussed.
Abstract: The effect of material strain-rate dependence on necking retardation is examined for biaxially-stretched sheets. Rate-dependent versions of both flow theory and deformation theory are employed in an analysis of the growth of long-wavelength nonuniformities. Material strain-rate sensitivity is seen to substantially increase the predicted limit strains beyond their corresponding values for time-independent material response. We also discuss the influence of strain-rate dependence on imperfection- sensitivity and forming limit curves.
147 citations
TL;DR: In this paper, the authors derived the expression for the susceptibility of CARS by means of the usual iterative treatment of density-matrix perturbations, and then showed that this derivation can be done in a straightforward manner by using a time-ordered diagrammatic representation, which brings novel physical insight into CARS mechanisms.
Abstract: We analyze the enhancement of the coherent anti-Stokes Raman-scattering (CARS) susceptibility when the frequencies of the waves involved are tuned into resonance with discrete and continuum one-photon absorptions, and discuss the applications. We first derive the expression for the susceptibility by means of the usual iterative treatment of density-matrix perturbations. We then show that this derivation can be done in a straightforward manner by means of a time-ordered diagrammatic representation, which brings novel physical insight into CARS mechanisms. This representation can also be used to analyze the transient behavior of CARS as the pump fields are turned on and off. In addition, we discuss resonant CARS spectroscopy in the gas phase. The spectrum is composed of the expected enhanced Raman lines and also of double-electronic-resonance lines. All these lines occur as doublets. We derive their relative intensities based on detunings, collisional broadening, Franck-Condon overlap integrals, and rotational transition moments. The line contours are predicted by representing the susceptibility in the complex plane. The problems arising from saturation and the optical Stark effect are also considered; all should be small below pump densities of 100 MW/${\mathrm{cm}}^{2}$ in gas mixtures near STP. Fluorescence interference is negligible, except at power densities high enough for the Stark effect to be large. Beam absorption is also negligible at STP if the resonant species' concentration is less than 1000 ppm; phase matching is then satisfied. Finally, an experimental resonant CARS spectrum of ${\mathrm{I}}_{2}$ at 1 mb in air near STP is presented and interpreted; the susceptibility is about 400 times larger than that of ${\mathrm{O}}_{2}$ off resonance and under the same thermodynamic conditions.
122 citations
TL;DR: In this article, the differential broadening pattern of an inert solute injected centrally into a regular (A) and a radially compressed (B) column has been studied and rationalized in terms of a semi-theoretical model that takes the radial diffusivity, the radial dependence of the lateral plate height and the peak local velocity into account.
102 citations
TL;DR: In this article, a theoretical model for the trajectories and temperature histories of particles injected in the fire-ball of an inductively coupled plasma was developed. But this model assumes that the internal plasma recirculation in the coil region is responsible for the bouncing of the particles on the fireball.
Abstract: A theoretical model has been developed for the calculation of the trajectories and temperature histories of particles injected in the fire-ball of an inductively coupled plasma. Calculations were made for alumina particles of different diameters ranging between 10 and 250 ?m. The particles were injected through a water cooled probe upstream of the fire-ball. The results shows that the internal plasma recirculation in the coil region is responsable for the bouncing of the particles on the fire-ball. Particles of the order of 10 ?m and smaler are entrained in the fire-ball by the inward radial flow caused by the electromagnetic pumping, and are subsequently completely evaporated. Larger particles, depending on their initial position and velocity of injection, could by-pass the plasma fire-ball, and in some cases, end up deposited on the wall of the plasma confining tube. Particles with diameters larger than 100 ?m were found to pass straight through the fire-ball when injected close to the center line of the torch.
01 Jan 1978
TL;DR: In this paper, two special solutions are used to illustrate the errors involved in the analysis of sheet necking from invoking plane stress assumptions, which lead to overestimates of the actual growth-rate.
Abstract: Two special solutions are used to illustrate the errors involved in the analysis of sheet necking from invoking plane stress assumptions. The first is an exact solution for the growth-rate of a small amplitude, sinusoidal thickness variation in a sheet of material characterized by \(\dot \in \) = ασ n in simple tension. The plane stress assumptions become accurate when the ratio of variation wavelength to average thickness exceeds four and otherwise lead to overestimates of the actual growth-rate. When this same ratio is approximately unity the relative size of the thickness variation decays with increasing deformation—an effect not predicted by a plane stress analysis. The second special solution is obtained using a perturbation expansion with the nonlinear long-wavelength solution (i.e., the plane stress solution) as the lowest order contribution. In this way explicit corrections to the plane stress solution are obtained. Selected comparisons with fully nonlinear finite element calculations are made.
TL;DR: In this article, the high-resolution infra-red spectrum of SiH4 in the region of 2101 cm-1 to 2265 cm1 has been analyzed and most of the lines observed have been assigned to transitions of the v 3 and v 1 bands of the abundant isotopic species 28SiH4.
Abstract: The high-resolution infra-red spectrum of SiH4 in the region 2101 cm-1 to 2265 cm-1 has been analysed. Most of the lines observed have been assigned to transitions of the v 3 and v 1 bands of the abundant isotopic species 28SiH4. The v 1 band is formally forbidden in the infra-red, but a vibration-rotation interaction between v 1 and v 3 lends intensity to the v 1 transitions. The spectrum has been fitted by diagonalizing the v 3 = 1 and v 1 = 1 hamiltonians coupled by the vibration-rotation interaction term. 500 transitions have been fitted with an overall standard deviation of 0·007 cm-1, using only 15 adjustable parameters (ten in the v 3 = 1 hamiltonian, four in the v 1 = 1 hamiltonian, and one interaction coefficient). The calculated intensities are also in good agreement with experiment. Transitions of the other isotopic species 29SiH4 and 30SiH4 have also been observed, but these spectra have not been analysed in detail.
TL;DR: In this paper, the first order Raman spectrum at room temperature of a layer type semiconducting compound InSe was reported and the structure was identified as ϵ polytype.
TL;DR: In this paper, the authors examined the effect of laser induced preassociation on the energy transfer between the radiative channel and the natural predissociation channel in the presence of natural (intrinsic) molecular pre-association.
TL;DR: In this article, the paramagnetic susceptibility of potassium-tetracyanoquinodimethane (K-TCNQ) as a function of temperature is analyzed. And the magnetic properties are described in terms of a Heisenberg exchange Hamiltonian between localized spins.
Abstract: The paramagnetic susceptibility of potassium-tetracyanoquinodimethane (K-TCNQ) as a function of temperature is analyzed. K-TCNQ is considered to be in the strong to intermediate correlation regime of the Hubbard model. The magnetic properties are described in terms of a Heisenberg exchange Hamiltonian between localized spins. The magnetic susceptibility of the high-temperature phase is fitted using the Heisenberg uniform-chain theory of Bonner and Fisher with an exchange constant $J$ which is temperature dependent as a result of the thermal expansion along the stacking axis. The low-temperature phase is described using a nonuniform Heisenberg chain with a temperature-dependent order parameter $\ensuremath{\delta}(T)$ having the BCS dependence as in the spin-Peierls transition. The phase transition comes from a complex displacive structural change between two locally stable overlapping modes of the TCN${\mathrm{Q}}^{\ensuremath{-}}$ anions which is driven by a dimerization instability of the spin-Peierls type.
TL;DR: The aspect of the rectal mucosa after administration of hypertonic enemas is occasionally confused with the macroscopic appearance of quiescent ulcerative colitis and the following features of an enema reaction were found to be useful: separation and mucous depletion of the glands (no observer variation).
Abstract: The aspect of the rectal mucosa after administration of hypertonic enemas is occasionally confused with the macroscopic appearance of quiescent ulcerative colitis Criteria for a diagnosis of enema reaction were derived from a retrospective series and tested prospectively on 11 healthy volunteers Photographs and biopsies were obtained before and after administration of a sodium phosphate hypertonic enema Three observers evaluated blindly the “before” and “after” macroscopic and microscopic pictures, graded the features, and made an overall diagnosis
TL;DR: 12 rheumatoid arthritic patients were controlled in a double‐blind crossover study with the same radioactive technique and there is a difference in favor of naproxen.
Abstract: Gastrointestinal bleeding is the most serious side effect encountered with the anti-inflammatory antirheumatic drugs. Using the 51Cr labeling technique, the comparative quantity of blood loss with aspirin or naproxen has been previously done on normal volunteers. With the present study, 12 rheumatoid arthritic patients were controlled in a double-blind crossover study with the same radioactive technique. There is a difference in favor of naproxen. The difference between the baseline period and naproxen administration was not statistically significant.
TL;DR: In this article, the thermoelectric power and transverse Nernst-Ettingshausen coefficient of cadmium arsenide at room temperature have been calculated as a function of electron concentration, taking into account the HgTe-type inverted electronic energy-band structure of this material.
Abstract: The thermoelectric power and the transverse Nernst-Ettingshausen coefficient of cadmium arsenide (${\mathrm{Cd}}_{3}$${\mathrm{As}}_{2}$) at room temperature have been calculated as a function of electron concentration, taking into account the HgTe-type inverted electronic-energy-band structure of this material. In the calculation, electron scattering due to polar-optical phonons, charged centers, and acoustical phonons has been considered. Since numerical values were available for every parameter involved except ${E}_{d}$, the acoustical-deformation-potential constant, the latter was treated as an adjustable parameter to fit the theoretical curves with experimental results. It was found that ${E}_{d}$ lies between 10 and 20 eV consistent with the approximate value estimated in a previous paper.
TL;DR: Primary monolayer cultures from whole mouse embryos were infected at 39° with ts -P155, an early temperature-sensitive mutant of polyoma virus that transforms but replicates poorly at this temperature, suggesting that most Cyp cells produce virus following transfer to 33°, in agreement with the results of infectious center assays.
TL;DR: The localization of catalase activity during the morphogenesis of duodenum and ileum has been studied in Swiss ICR mouse embryos from the 16th day of fetal life until birth and the biogenesis of microperoxisimes in the small intestine before birth is discussed.
TL;DR: The postnatal development of phosphohydrolase activity of glucose-6-phosphatase has been examined in the different parts of the small intestine of the mouse and compared with that of trehalase and glucoamylase.
TL;DR: A modification of the classic Anson assay for proteolytic enzymes which are active in the acidic pH range is proposed, which abolishes many of the constraints common to this widely used method.
TL;DR: In vivo and in vitro experiments the enzyme was found to cleave main core polypeptide PVII to VII and Phenylmethylsulfonyl fluoride and SDS inhibited its activity completely and EDTA did not seem to inhibit its activity.
TL;DR: In this paper, the vibration-rotation spectrum of HCP was recorded in the region of the ν 1 band with a resolution of about 0.035 cm−1.
TL;DR: In this paper, the line width and level shift for the harmonic oscillator predissociated by a linear potential were derived for the B 3 Σ u − − 1 Π u curve crossing in O 2.
TL;DR: The experiments did not demonstrate a significant difference among the number of reflexes elicited in rabbits injected with either naloxone, or saline solution or in a control series, suggesting that the opiate receptor function is not essential to the induction and maintenance of the immobility reflex.
TL;DR: A thorough investigation of vestibular function has been carried out in 16 patients with typical Friedreich's ataxia, and most abnormal findings were related to ocular dysmetria, disorganized pursuit and square waves.
Abstract: A thorough investigation of vestibular function has been carried out in 16 patients with typical Friedreich's ataxia. Electronystagmography and caloric tests revealed a number of inconstant abnormalities. Most abnormal findings were related to ocular dysmetria, disorganized pursuit and square waves.
TL;DR: Explants of adult mouse jejunum have been maintained in organ culture with or without fructose added to the medium in order to stimulate the intestinal glucose- 6-phosphatase (G-6-Pase) and the ultrastructural localization of the G-6,Pase is not altered during the culture.
Abstract: Explants of adult mouse jejunum have been maintained in organ culture with or without fructose added to the medium in order to stimulate the intestinal glucose-6-phosphatase (G-6-Pase). When the fructose is added, at the beginning of the culture, a three-fold increase of G-6-Pase in measured during the first 24 h. If the fructose is added after 24 h of culture, no significant increase of the G-6-Pase is registered in comparison with the controls. Proteins, DNA content and dissacharidase activities are not modified during the culture. Alkaline phosphatase activity presents a twofold increase in the controls and stimulated explants. The ultrastructural localization of the G-6-Pase is not altered during the culture.
TL;DR: The object of this work is to investigate the problem of Volterra systems driven by random inputs and to obtain closed-form equations for the cross-power and output power spectral densities of a VolterRA system driven by a real, stationary, zero-mean Gaussian input.
Abstract: The object of this work is to investigate the problem of Volterra systems driven by random inputs. General expressions for the second-order output statistics of a Volterra system are obtained and formalized. The input-output crosscorrelation and output autocorrelation functions are expressed in terms of higher order input autocorrelation functions. In the frequency domain, the cross-power and output power spectral densities are expressed in terms of higher order input power spectral densities. These expressions are used to obtain closed-form equations for the cross-power and output power spectral densities of a Volterra system driven by a real, stationary, zero-mean Gaussian input.