Electronic Structure Of The Hydride Pd3feh

A self-consistent calculation of the electronic structure of Pd3FeH is presented, using the linear combination of muffin-tin orbitals method. We first briefly discuss the paramagnetic phase of the hydride. We then proceed to the discussion of the ferromagnetic phase of Pd3FeH. The analysis of the energy bands and densities of states gives a good understanding of the influence of hydrogen in this compound. We show any hydrogen uptake drastically decreases the magnetic moments of Pd3Fe. We also find a marked increase in the linear coefficient of specific heat, showing great alterations in the physical properties of Pd3Fe upon hydrogenation. © 1987 The American Physical Society.36145245

Magnetic Properties And Calculated Electronic Structure Of Iron-palladium Alloys

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The electronic structure of iron-palladium alloys are studied using the self-consistent linear muffin-tin orbital (LMTO) method. In particular, three compounds are analyzed, namely, Pd3Fe, PdFe, and PdFe3 and their stability investigated with respect to the iron concentration. Results are obtained from ferromagnetic calculations for each alloy. Our discussion on internal excess energy shows the PdFe3 ordered structure to be at best metastable with respect to its disordered alloy, while Pd3Fe and PdFe are stable compounds. Results for PdFe3 show a collapse of its magnetic moment as a function of the lattice parameter. © 1992 The American Physical Society.461489158925 2010/00863-0; FAPESP; São Paulo Research Foundation; 2011/09240-9; FAPESP; São Paulo Research Foundation; 2012/21198-0; FAPESP; São Paulo Research FoundationFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Environmental Services Associated With The Reclamation Of Areas Degraded By Mining: Potential For Payments For Environmental Services

This paper discusses the potential of associating environmental services (ES) with techniques for reclaiming degraded areas (RDA) used in the mining sector, considering the current trends in payments for environmental services (PES) in Brazil. A literature review with content analysis generated results which identified the ES generated for eight cases of RDA in mining. As an example, ES related to soil enhancement were found. A more extended review of general RDA techniques confirmed the potential for associating other ES to RDA techniques used in mining, an example here is the enhancement of carbon stocks. Support for actions could come from existing PES schemes, particularly for cases where the ES identified as associated with an RDA technique are related to soil and water conservation. Concluding remarks indicate that there is a potential scenario for ES diversification in the reclamation stage of mining operations. A first step towards accomplishing this diversification envisages the creation of a PES scheme specific to the mining sector. Further studies are needed to develop criteria for fostering a PES scheme specifically for the reclamation phase of mining operations in Brazil.19213716

Effect of Insecticides Sprayed on Leaves and Applied via Soil to Aphis illinoisensis Shimer, 1866 (Hemiptera: Aphididae) on Grapevines

High infestations by the grapevine aphid Aphis illinoisensis (Hemiptera: Aphididae) have been observedin vineyards in southern Brazil, retarding plant growth and causing premature berry drop. This studyevaluated the effect of insecticides on the control of the species in two experiments carried out in agreenhouse. The first control experiment for A. illinoisensis was conducted with seedlings of Vitis viniferavar. ‘Cabernet Franc’ to assess the effect of azadirachtin (Azamax®) at dosages of 2.4 and 3.6 mL a.i.(active ingredient)/100 L of water, with reapplication seven days after the first application (DAFA). Tocompare its effect, the neonicotinoids imidacloprid (Provado 200 SC®) and thiamethoxam (Actara 250WG®) were sprayed at dosages of 8 mL or g a.i./100 L of water in foliar application without reapplication.The second experiment compared the effect on A. illinoisensis by spraying these neonicotinoids at dosagesof 8 mL or g a.i./100 L in foliar applications and of 0.05 mL or g a.i./100 L applied in the soil. Evaluationswere performed at 0, 1, 5, 7, 10 and 14 DAFA. Imidacloprid and thiamethoxam effectively controlled A.illinoisensis in both forms of application [soil and foliar], while azadirachtin at the dosage of 3.6 ml a.i./100L reapplied seven days after the first application provided 55.7% control. In conclusion, A. illinoisensis canbe controlled effectively by employing neonicotinoids in the soil, while azadirachtin can be an alternativeto reduce infestation pressure

Partial Recovery Of Erythrocyte Glycogen In Diabetic Rats Treated With Phenobarbital

Erythrocytes may play a role in glucose homeostasis during the postprandial period. Erythrocytes from diabetic patients are defective in glucose transport and metabolism, functions that may affect glycogen storage. Phenobarbital, a hepatic enzyme inducer, has been used in the treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM), increasing the insulin-mediated glucose disposal. We studied the effects of phenobarbital treatment in vivo on glycemia and erythrocyte glycogen content in control and alloxan-diabetic rats during the postprandial period. In control rats (blood glucose, 73 to 111 mg/dl in femoral and suprahepatic veins) the erythrocyte glycogen content was 45.4 ± 1.1 and 39.1 ± 0.8 μg/g Hb (mean ± SEM, N = 4-6) in the femoral artery and vein, respectively, and 37.9 ± 1.1 in the portal vein and 47.5 ± 0.9 in the suprahepatic vein. Diabetic rats (blood glucose, 300-350 mg/dl) presented low (P < 0.05) erythrocyte glycogen content, i.e., 9.6 ± 0.1 and 7.1 ± 0.7 μg/g Hb in the femoral artery and vein, respectively, and 10.0 ± 0.7 and 10.7 ± 0.5 in the portal and suprahepatic veins, respectively. After 10 days of treatment, phenobarbital (0.5 mg/ml in the drinking water) did not change blood glucose or erythrocyte glycogen content in control rats. In diabetic rats, however, it lowered (P < 0.05) blood glucose in the femoral artery (from 305 ± 18 to 204 ± 45 mg/dl) and femoral vein (from 300 ± 11 to 174 ± 48 mg/dl) and suprahepatic vein (from 350 ± 10 to 174 ± 42 mg/dl), but the reduction was not sufficient for complete recovery. Phenobarbital also stimulated the glycogen synthesis, leading to a partial recovery of glycogen stores in erythrocytes. In treated rats, erythrocyte glycogen content increased to 20.7 ± 3.8 μg/g Hb in the femoral artery and 30.9 ± 0.9 μg/g Hb in the suprahepatic vein (P < 0.05). These data indicate that phenobarbital activated some of the insulin-stimulated glucose metabolism steps which were depressed in diabetic erythrocytes, supporting the view that erythrocytes participate in glucose homeostasis.305657661Burant, C.F., Sivitz, W.I., Fukumoto, H., Kayano, T., Nagamatsu, S., Seino, S., Pessin, J.E., Bell, G.I., Mammalian glucose transporters: Structure and molecular regulation (1991) Recent Progress in Hormone Research, 47, pp. 1-41Zoccoli, M.A., Boldwin, S.A., Lienhard, G.E., Monosaccharide transport system of the human erythrocyte (1978) Journal of Biological Chemistry, 253, pp. 69213-69230Rapoport, S., The regulation of glycolysis in mammalian erythrocytes (1968) Essays in Biochemistry, 4, pp. 69-103Jacquez, J.A., Red blood cell as glucose carrier: Significance for placental and cerebral glucose transfer (1984) American Journal of Physiology, 246, pp. 289-298Ferranini, E., Bjorkman, O., Role of red blood cells in the regulation of blood glucose levels in man (1986) Diabetes, 35 (1 SUPPL.), p. 39. , AbstractGuarner, V., Alvarez-Buylla, R., Erythrocyte and glucose homeostasis in rats (1989) Diabetes, 38, pp. 410-415Hers, H.G., Verhue, W., Van Hoof, F., The determination of amylo-1,6-glucosidase (1967) European Journal of Biochemistry, 2, pp. 256-264Moses, S.W., Bashan, N., Gutman, A., Properties of glycogen synthetase in erythrocytes (1972) European Journal of Biochemistry, 30, pp. 205-210Garvey, W.T., Hueckstedt, T.P., Olefsky, J.M., Glucose and insulin co-regulate the glucose transport system in primary cultured adipocytes. A new mechanism of insulin resistance (1987) Diabetes, 36 (1 SUPPL.), p. 84. , AbstractRapin, J.R., Lespinasse, C., Yoa, R., Wiernsperger, N., Erythrocyte glucose consumption in insulin-dependent diabetes: Effect of metformin in vitro (1991) Diabete et Metabolisme, 14, pp. 164-167Lahtela, J.T., Sarkka, P., Sotaniemi, E.A., Phenobarbital treatment enhances insulin mediated glucose metabolism in man' (1984) Research Communications in Chemical Pathology and Pharmacology, 44, pp. 215-226Lahtela, J.T., Gachalyi, B., Eksyma, S., The effect of liver microsomal enzyme inducing and inhibiting drugs on insulin mediated glucose metabolism in man (1986) British Journal of Clinical Pharmacology, 21, pp. 19-26Lahtela, J.T., Arranto, A.J., Sotaniemi, E.A., Enzyme inducers improve insulin sensitivity in non-insulin-dependent diabetic subjects (1985) Diabetes, 34, pp. 911-916Farquharson, J., Jamieson, E.C., MacPhee, G.B., Logan, R.W., A new sensitive microassay for the measurement of erythrocyte glycogen (1990) Clinica Chimica Acta, 187, pp. 89-94Venkatsen, N., Davidson, M.B., Simsolo, R.B., Kern, P.A., Phenobarbital treatment enhances insulin-mediated glucose metabolism and improves lipid metabolism in the diabetic rat (1994) Metabolism: Clinical and Experimental, 43, pp. 348-356Thurman, R.G., Kauffman, F.C., Factors regulating drug metabolism in the intact hepatocytes (1980) Pharmacological Reviews, 31, pp. 229-251Karvonen, I., Stengard, J.H., Huupponen, R., Effects of enzyme induction therapy on glucose and drug metabolism in obese mice model of non-insulin dependent diabetes mellitus (1989) Diabetes Research, 10, pp. 85-92Villar-Palasi, C., Effect of glucose phosphorylation on the activation by insulin of skeletal muscle glycogen synthase (1995) Biochimica et Biophysica Acta, 1244, pp. 203-20

Binary Collisions and the Slingshot Effect

We derive the equations for the gravity assist manoeuvre in the general 2D case without the constraints of circular planetary orbits or widely different masses as assumed by Broucke, and obtain the slingshot conditions and maximum energy gain for arbitrary mass ratios of two colliding rigid bodies. Using the geometric view developed in an earlier paper by the authors the possible trajectories are computed for both attractive or repulsive interactions yielding a further insight on the slingshot mechanics and its parametrization. The general slingshot manoeuvre for arbitrary masses is explained as a particular case of the possible outcomes of attractive or repulsive binary collisions, and the correlation between asymptotic information and orbital parameters is obtained in general.Comment: 12 pages, 7 figures, accepted for publication Dec'07, Celestial Mechanics and Dynamical Astronom

Lack of tolerance for the anti-dyskinetic effects of 7-nitroindazole, a neuronal nitric oxide synthase inhibitor, in rats

7-Nitroindazole (7-NI) inhibits neuronal nitric oxide synthase in vivo and reduces l-DOPA-induced dyskinesias in a rat model of parkinsonism. The aim of the present study was to determine if the anti-dyskinetic effect of 7-NI was subject to tolerance after repeated treatment and if this drug could interfere with the priming effect of l-DOPA. Adult male Wistar rats (200-250 g) with unilateral depletion of dopamine in the substantia nigra compacta were treated with l-DOPA (30 mg/kg) for 34 days. On the 1st day, 6 rats received ip saline and 6 received ip 7-NI (30 mg/kg) before l-DOPA. From the 2nd to the 26th day, all rats received l-DOPA daily and, from the 27th to the 34th day, they also received 7-NI before l-DOPA. Animals were evaluated before the drug and 1 h after l-DOPA using an abnormal involuntary movement scale and a stepping test. All rats had a similar initial motor deficit. 7-NI decreased abnormal involuntary movement induced by l-DOPA and the effect was maintained during the experiment before 7-NI, median (interquartile interval), day 26: 16.75 (15.88-17.00); day 28: 0.00 (0.00-9.63); day 29: 13.75 (2.25-15.50); day 30: 0.5 (0.00-6.25); day 31: 4.00 (0.00-7.13), and day 34: 0.5 (0.00-14.63), Friedman followed by Wilcoxon test,vs day 26, P < 0.05;. The response to l-DOPA alone was not modified by the use of 7-NI before the first administration of the drug (l-DOPA vs time interaction, F1,10 = 1.5, NS). The data suggest that tolerance to the anti-dyskinetic effects of a neuronal nitric oxide synthase inhibitor does not develop over a short-term period of repeated administration. These observations open a possible new therapeutic approach to motor complications of chronic l-DOPA therapy in patients with Parkinson&#8217;s disease

Indirect optical transitions from carriers trapped on the delta doping and on the parabolic quantum well

AbstractIn this work, doped AlGaAs/GaAs parabolic quantum wells (PQW) with different well widths (from 1000Å up to 3000Å) were investigated by means of photoluminescence (PL) measurements. In order to achieve the 2DEG inside the PQW Si delta doping is placed at both side of the well. We have observed that the thickness of this space layer plays a major rule on the characteristics of the 2DEG. It has to be thicker enough to prevent any diffusions of Si to the well and thin enough to allow electrons migration inside the well. From PL measurement, we have observed beside the intra well transitions, indirect transitions involving still trapped electron on the delta doping and holes inside the PQW. For the thinness sample, we have measured a well defined PL peak at low energy side of the GaAs bulk emission. With the increasing of the well thickness this peak intensity decreases and for the thickest sample it almost disappears. Our theoretical calculation indicated that carriers (electron and holes) are more placed at the center of the PQW. In this way, when the well thickness increases the distance between electrons on the delta doping and holes on the well also increases, it decreases the probability of occurrence of these indirect optical transitions

Video-game epilepsy: a European study.

Epilepsia. 1999;40 Suppl 4:70-4. Video-game epilepsy: a European study. Kasteleijn-Nolst Trenité DG, da Silva AM, Ricci S, Binnie CD, Rubboli G, Tassinari CA, Segers JP. Stichting Epilepsie Instellingen Nederland, Heemstede, The Netherlands. [email protected] Abstract With the introduction of Nintendo video-games on a large scale, reports of children having seizures while playing suggested a possible specific, provocative factor. Although 50% of the photosensitive patients are also sensitive to a 50-Hz television, nonphotosensitive patients with a history of video-game seizures were described as well. The question arises whether this is a mere coincidence, provoked by fatigue and stress, is related to the reaction to the television screen itself, or depends on the movement and color of the pictures of this specific game. A European study was performed in four countries and five sites. All patients were selected because of a history of television, video- or computer-game seizures, with a history of sun-light-, discotheque-, or black and white pattern-evoked seizures, or were already known to be sensitive to intermittent photic stimulation. A total of 387 patients were investigated; 220 (75%) were female and 214 (55%) of those were < 18 years of age. After a routine examination, intermittent photic, pattern, and television stimulation were performed in a standardized way. The patients were investigated with Super Mario World and a standard relatively nonprovocative TV program, both on a 50- and 100-Hz television. Regardless of the distance, Super Mario World proved to be more provocative than the standard program (Wilcoxon, p < 0.05). Eighty-five percent showed epileptiform discharges evoked by intermittent photic stimulation. Forty-five percent of patients were 50-Hz television sensitive and 26% were 100-Hz television sensitive. Pattern sensitivity was found in 28% of patients. The patients, referred because of a television, video- or computer-game seizure, were significantly more sensitive to pattern and to the 50-Hz television (chi square, p < 0.001). More patients are sensitive when playing Super Mario, compared with the standard program (Wilcoxon, p = 0.001) and more sensitive with playing versus viewing (p = 0.016). Of the patients who were referred because of seizures in front of the television, or evoked by a video- or computer game, 14% proved not to be photosensitive. Although no difference in age or use of medication was found, twice as many men were found in this nonphotosensitive group. PMID: 10487177 [PubMed - indexed for MEDLINE