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G Roux

Publications and source records attributed to G Roux.

At least 19 recordsLinked to original sources
PubMed2006

Zeeman effect in superconducting two-leg ladders: irrational magnetization plateaus and exceeding the Pauli limit.

The effect of a parallel magnetic field on superconducting two-leg ladders is investigated numerically. The magnetization curve displays an irrational plateau at a magnetization equal to the hole density. Remarkably, its stability is fundamentally connected to the existence of a well-known magnetic resonant mode. Once the zero-field spin gap is suppressed by the field, pairs acquire a finite momentum characteristic of a Fulde-Ferrell-Larkin-Ovchinnikov phase. In addition, Sz = 0 triplet superconducting correlations coexist with singlet ones above the irrational plateau. This provides a simple mechanism in which the Pauli limit is exceeded as suggested by recent experiments.

Journal Article↗
PubMed2006

Very high ethanol productivity in an innovative continuous two-stage bioreactor with cell recycle.

The performance of an innovative two-stage continuous bioreactor with cell recycle-potentially capable of giving very high ethanol productivity-was investigated. The first stage was dedicated to cell growth, whereas the second stage was dedicated to ethanol production. A high cell density was obtained by an ultrafiltration module coupled to the outlet of the second reactor. A recycle loop from the second stage to the first one was tested to improve cell viability and activity. Cultivations of Saccharomyces cerevisiae in mineral medium on glucose were performed at 30 degrees Celsius and pH 4. At steady state, total biomass concentrations of 59 and 157 gDCW l(-1) and ethanol concentrations of 31 and 65 g l(-1) were obtained in the first and second stage, respectively. The residual glucose concentration was 73 g l(-1) in the first stage and close to zero in the second stage. The present study shows that a very high ethanol productivity (up to 41 g l(-1) h(-1)) can indeed be obtained with complete conversion of the glucose and with a high ethanol titre (8.3 degrees GL) in the two-stage system.

Bioreactors↗
PubMed2001

Excess sludge reduction in activated sludge processes by integrating biomass alkaline heat treatment.

With new EC regulations, alternative treatment and disposal techniques of the excess sludge produced by activated sludge wastewater treatment plants have to be developed. To decrease activated sludge production yield, microbial cell lysis can be amplified to enhance cryptic growth (biomass growth on lysates). Cell breakage techniques (thermal, alkaline and a combination) were studied to generate Ralstonia eutropha (strain model) and waste activated sludge lysates and to evaluate their biodegradability. Gentle treatment conditions by alkaline waste treatment (20 min at 60 degrees C and pH 10 by NaOH addition) allowed waste activated sludge to be solubilized by a two step process (instantaneous and post-treatment) giving a dissolved organic carbon released by the total suspended solids treated of 267 mgDOC x g(-1)TSS. The biodegradation of the soluble fraction of the lysates by fresh sludge reached 75 and 90% after 48 and 350 hrs of incubation respectively. A validation on a laboratory scale by insertion of a liquor alkaline heat treatment loop in a biological synthetic wastewater treatment process was carried out. A reduction of 37% of the excess sludge was obtained without altering the purification yield of the process.

Biodegradation, Environmental↗
PubMed2000

Crystal structures of human pancreatic alpha-amylase in complex with carbohydrate and proteinaceous inhibitors.

Crystal structures of human pancreatic alpha-amylase (HPA) in complex with naturally occurring inhibitors have been solved. The tetrasaccharide acarbose and a pseudo-pentasaccharide of the trestatin family produced identical continuous electron densities corresponding to a pentasaccharide species, spanning the -3 to +2 subsites of the enzyme, presumably resulting from transglycosylation. Binding of the acarviosine core linked to a glucose residue at subsites -1 to +2 appears to be a critical part of the interaction process between alpha-amylases and trestatin-derived inhibitors. Two crystal forms, obtained at different values of pH, for the complex of HPA with the protein inhibitor from Phaseolus vulgaris (alpha-amylase inhibitor) have been solved. The flexible loop typical of the mammalian alpha-amylases was shown to exist in two different conformations, suggesting that loop closure is pH-sensitive. Structural information is provided for the important inhibitor residue, Arg-74, which has not been observed previously in structural analyses.

Acarbose↗
PubMed1999

Relinquishing the need to "fix it": medical intervention with domestic abuse.

The grounded theory method was used to study obstetricians/gynecologists' interactions with victims of domestic abuse. Double-bind conflict emerged as the basic social psychological problem. Physicians struggled between approaching domestic abuse as a legitimate medical problem or retreating from it as an overwhelming social issue. Resolution occurred through a three-stage process that changed the doctors' objective from "fixing" the abuse to supporting the patient. This goal revision required education on the dynamics of domestic abuse, confrontation of personal issues, and formation of community partnerships. Implications include development of curricula and protocols to create a united front against domestic abuse within health care, social service, legal, and law enforcement communities.

Attitude of Health Personnel↗
PubMed1992

[Synthesis and pharmacology of structural analogs of tienilic acids].

Three structural analogs of tienilic acid were synthetized and evaluated for their diuretic activity in the rat. Two compounds are alpha substituted tienilic acid derivatives by an alkylated group. The third one is a conformationally restricted derivative through a cyclization process. All compounds fall to increase the urinary flow in the pharmacological assay.

Animals↗
PubMed1987

Effect of pelleting and associations with maize or wheat on the nutritive value of smooth pea (Pisum sativum) seeds in adult cockerels.

Four types of diet were tested: 960 g maize/kg (M), 960 g wheat/kg (W), 463 g maize added to 497 g of smooth peas/kg (PM) and 463 g wheat added to 497 g smooth peas/kg (PW). Three treatments were applied to each of these 4 diets: grinding (OP), one steam pelleting (1 P) and two successive steam pelleting (2 P). The pelleted diets were ground before feeding. Adult cockerels received all the diets whereas rats received only W and PW diets. Apparent metabolisable energy values corrected for N-equilibrium (AMEn), protein and starch digestibilities were measured in adult cockerels. Digestible energy (DE) values were measured in rats. The AMEn values of cereals remained practically unchanged by pelleting, whereas that of smooth peas was increased by between 1.8-4.6% after pelleting. Pelleting also induced 3.5 and 5.4% increases respectively in the digestibilities of pea protein and starch. Pelleting did not change the DE values measured in rats. The AMEn values of smooth peas mixed with maize were 4.6% higher than those of smooth peas mixed with wheat. The true digestibility of pea protein was 8.4% higher in the former mixture, whereas the pea starch digestibility remained unchanged. Calculation showed that most of the pea AMEn variations could be explained in terms of variations in protein and starch digestibilities.

Animal Feed↗
PubMed1985

[Action of 13-cis-retinoic acid and aromatic retinoid on several cutaneous parameters in hyperseborrheic rats].

Castrated rats submitted to androgenic stimulation present hyperseborrhea with an increase in foamy cells associated with an increase in cutaneous lipids and a change in the number of epidermal cell layers. 13-cis-retinoic acid and aromatic retinoid (Ro 10-9359) were given orally during 17 days (10 mg/kg) to castrated rats which had received a testosterone implant. Cyproterone acetate was chosen as the antiandrogenic drug; it was given at doses of 10 mg/kg i.m. once every other day. As opposed to cyproterone acetate, the two substances studied had no effect on the seminal vesicle and ventral prostate. 13-cis-retinoic acid and retinoic aromatic acid increased the total number of epidermal layers: In the case of 13-cis-retinoic acid, the increase involves especially the nonnucleated cell layers, whereas with retinoid aromatic acid it involves the nucleated cell layer. The number of sebaceous glands is not changed by either products, on the other hand, the number of foamy cells is considerably decreased and the weight of cutaneous lipids is decreased as well.

Animals↗
PubMed1985

[Changes in water metabolism in rats under the influence of naloxone: role of vasopressin].

The effect of naloxone (0.6 mg; 1.2 mg; 2.4 mg X kg-1) were compared in normal Long Evans (N) and Brattleboro (D.I.) conscious rats. Naloxone did not change the values of drinking, diuresis, food intake, blood pressure, Na+ and K+ urinary excretion measured during 24 hours. During the two hours following drug injection, naloxone (1.2 and 2.4 mg X kg-1) reduced diuresis in normal as well as in D.I. rats. Water drinking was only modified in D.I. rats: this effect was shown to be a consequence of antidiuresis. These results suggest that the antidiuretic properties of naloxone are independent of vasopressin secretion. They do not support in a role of opiate receptors on vasopressin secretion in normal hydrated animals.

Animals↗
PubMed1985

[Radiation and surgical treatment of cancer of the cervix uteri in proximal stages I and II].

No results from therapeutic trials describing the best therapeutic procedure for cervical carcinoma in stages I and IIa are available. Analysis of a series of 242 cases of cervical carcinoma in stages I and IIa, from 1975 to 1980, treated with radical surgery and radiation therapy, yields a therapeutic approach that envisions the most reliable evaluation of subclinical extension, cure of cervical tumor and prevention of pelvic or extra-pelvic metastases with a minimum of post-radiation problems. The choice of combination surgery and radiation therapy is primarily determined by staging and the volume of the central pelvic tumor. For stages I and IIb (upper third of vagina involved) with central pelvic tumor less than 4 cm in diameter, the usual procedure is recommended i.e. radium application, total hysterectomy with pelvic lymphadenectomy followed by external irradiation of pelvic lymphatics in cases with lymphadenopathy. For stages IIb (obvious parametrial involvement) and for stages I or II with central pelvic tumor between 4 and 6 cm in diameter: total dose external and internal pelvic radiation therapy followed by total hysterectomy without pelvic lymphadenectomy but with exploration of obturator, hypogastric, external iliac, common iliac, and aortic nodes. For the rare supravaginal central pelvic tumors greater than 6 cm in diameter, the risk of clinical evaluative error and incomplete sterility by irradiation alone, warrants first an explorative laparotomy using Wertheim's procedure, then pelvic lymphadenectomy and exploration of pelvic and aortic lymph nodes.

Adult↗
PubMed1979

[The hepatitis B virus markers, in leprous patients (author's transl)].

The hepatitis B virus markers were studied on 553 leprous sera and 100 controls sera. HBs Ag detected by RIA were present on 25,4% of leprous and 12% of controls; the anti-HBs by RIA were revealed in 44,1% of patients out 38% of controls. The leprous was not carrying this markers were HBe Ag or anti-HBe or anti-HBc positive. By this vertical study it appears that 2,4% of the cases presented recent or acute hepatitis; 23% were chronic carriers; 41,7% had been in times past infected but were cured and the third remaining had been infected but coat markers were absent, it is more than likely that is an old infected group. The study revealed no significant difference in hepatitis chronic forms frequency between lepromatous and tuberculoïd patients.

Adult↗
PubMed1979

[The value of tomodensitometry in the treatment of carcinoma of the uterus (author's transl)].

The authors performed pelvic and lumbo-aortic tomodensitometry (TDM) in 67 patients with invasive carcinoma of the cervix. Localisation of the cervix is aided by the insertion of a vaginal marker and by opacification of the bladder and rectum. The density and appearance of tumour tissue are identical to those of normal uterine muscle. Under such conditions, TDM is of no use in seeing partial or total involvement of the cervix without any increase in cervical size. TDM gives a clear picture of hypertrophic neoplastic cervices and may be used to obtain exact measurements. TDM offers valuable information in cases of spread to the parametrium, lymphadenopathy or visceral metastases. During radium therapy, TDM shows the relationships between the radioactive sources and the centri-pelvic tumour. It facilitates the drawing of isodose curves. TDM is not a method suitable for the early diagnosis of carcinoma of the cervix. It adds very useful complementary information to clinical examination and classical investigation.

Female↗