New Compactifications of Supergravities and Large N QCD

We construct supergravity backgrounds representing non-homogeneous compactifications of d=10,11 supergravities to four dimensions, which cannot be written as a direct product. The geometries are regular and approach $AdS_7\times S^4$ or $AdS_5\times S^5$ at infinity; they are generically non-supersymmetric, except in a certain "extremal" limit, where a Bogomol'nyi bound is saturated and a naked singularity appears. By using these spaces, one can construct a model of QCD that generalizes by one (or two) extra parameters a recently proposed model of QCD based on the non-extremal D4 brane. This allows for some extra freedom to circumvent some (but not all) limitations of the simplest version.Comment: two small misprints corrected, to appear in Nucl.Phys.B, 17 pages, harvma

Multi-phonon scattering and Ti-induced hydrogen dynamics in sodium alanate

We use ab initio methods and neutron inelastic scattering (NIS) to study the structure, energetics, and dynamics of pure and Ti-doped sodium alanate (NaAlH_4), focusing on the possibility of substitutional Ti doping. The NIS spectrum is found to exhibit surprisingly strong and sharp two-phonon features. The calculations reveal that substitutional Ti doping is energetically possible. Ti prefers to substitute for Na and is a powerful hydrogen attractor that facilitates multiple Al--H bond breaking. Our results hint at new ways of improving the hydrogen dynamics and storage capacity of the alanates.Comment: 5 pages, with 4 postscript figures embedded. Uses REVTEX4 and graphicx macro

A short-term low-protein diet reduces glomerular filtration rate in insulin-dependent diabetes mellitus patients

I. The effect of a 7-day low-protein diet on renal function was studied in 17 normotensive, normoalbuminuric, insulin-dependent diabetes mellitus (IDDM) patients. Glomerular filtration rate (GFR) and urinary albumin excretion (UAE) were measured after 7 days on an isocaloric low-protein diet (0.5 g protein/kg per day). 2. Compliance was confirmed by 24-h urinary urea levels. GFR was measured after a single injection of 5Icr-EDTA and UAE by radioimmunoassay. 3. GFR was reduced by 13.8% on the low-protein diet (139.9 ±27.7 vs 120.4 ±25.1 rn1 min-I (1.73 m2)-l) (P<0.05). This effect was of the same magnitude as that obtained by others after long-term strict metabolic control. No changes were observed in UAE (5.6 ± 6.4 vs 5.7 ± 6.8 f.Lg/min) during the study. The patients were classified as hyperfiltering (N = 9; GFR = 160.3 ± 16.6 rn1 min-I (1.73 m2)-l) or normofiltering (N = 8; GFR = 117.1 ± 17.6 ml min-I (1.73 m2)-l) on the basis ofGFR, and no difference in the reduction of GFR was observed in either group. 4. The reduction in GFR is probably caused primarily by the reduction of protein intake since other factors that might influence the GFR such as glucose control and blood pressure did not change during the study

Is endogenous creatinine clearance still a reliable index of glomerular filtration rate in diabetic patients?

Three methods routinely used for estimation of renal function - plasma creatinine, endogenous creaumne clearance and estimation of endogenous creatinine clearance from plasma creatinine - are compared with the measurement of glomerular filtration rate based on a single injection of 5lcr-EDTA, a technique that was standardized for this study in 20 healthy volunteers. The different creatinine methods were compared with the 5Icr-EDTA method in 30 diabetic patients, resulting in 68 sets of data in which all four estimates were made simultaneously. Spearman's correlation values (rs) for comparing the three creatinine methods with that of 5lcr-EDTA were 0.74, 0.40 and 0.82 (P<0.05). It is suggested that the use of endogenous creatinine clearance to estimate the glomerular filtration rate (GFR) requires caution and the recognition of the limitations of the method, and that simpler techniques (serum creatinine or estimated endogenous creatinine clearance) are preferable in routine practice. GFR based on 51Cr-EDTA injection is the method of choice for monitoring renal function in special situations such as renal transplantation and progressive nephropathies

A hiperfiltração glomerular está associada a alterações de pressão sangüínea em pacientes DMDI normotensivos

OBJECTIVE: To analyze the blood pressure patterns in normoalbuminuric IDDM patients with glomerular hyperfiltration. PATIENTS AND METHODS: A controlled cross-sectional study of 38 normotensive normoalbuminuric (urinary albumin excretion rate 134 ml × min-1× 1.73m-2] and 20 normofiltering) and 20 normal individuals matched for age, sex, and body mass index was performed. The 24-h ambulatory blood pressure was monitored using an auscultatory technique; the glomerular filtration rate was measured by 51Cr-labeled EDTA method; extracellular volume by the distribution volume of 51Cr-labeled EDTA; and 24-h urinary albumin excretion rate by radioimmunoassay. RESULTS: Mean nocturnal diastolic blood pressure was higher in hyperfiltering IDDM patients (70.4 ± 7.8 mmHg), when compared with the control group (65.1 ± 5.3 mmHg, P = 0.04). Diastolic blood pressure night:day ratio was higher in hyperfiltering IDDM patients (92.0 ± 8.6%), when compared with normofiltering IDDM patients (85.9 ± 4.8%) and control subjects (87.0 ± 6.8%, P = 0.02). In IDDM patients, the glomerular filtration rate significantly correlated with the diastolic blood pressure night:day ratio (r = 0.5, P = 0.002), extracellular volume (r = 0.4, P = 0.002), and HbA1 (r = 0.3, P = 0.03). In stepwise multiple regression analysis, factors associated with glomerular filtration rate were diastolic blood pressure night:day ratio, extracellular volume, and HbA1 (adjusted r2 = 0.27, P = 0.003). CONCLUSIONS: Glomerular hyperfiltration is associated with higher nocturnal diastolic blood pressure and with a blunted nocturnal decrease in diastolic blood pressure levels in normotensive and normoalbuminuric IDDM patients.OBJETIVO: Analisar os padrões de pressão sangüínea em pacientes normoalbuminúricos DMDI com hiperfiltração glomerular. PACIENTES E MÉTODOS: Foi feito um estudo controlado em cortes transversais com 38 pacientes normoalbuminúricos normotensivos (taxa de excreção urinária de albumina>20 mg/min) DMDI (hiperfiltração em 18 [taxa de filtração glomerular>134 ml x min-1 x 1,73m-2] e normofiltração em 20), e de 20 indivíduos normais agrupados por idade, sexo, e índice de massa corporal. A pressão sangüínea ambulatorial foi monitorada em 24 h pelo métodoauscultatório; a taxa de filtração glomerular foi medida através do método 51Cr-EDTA; o volume extracelular, através do volume de distribuição do 51Cr- EDTA; e a taxa excreção urinária de albumina em 24 h, por radioimunoensaio RESULTADOS: A média da pressão sangüinea diastólica noturna foi mais alta em pacientes DMDI com hiperfiltração (70,4 + 7,8 mmHg), quando comparada à do grupo controle (65,1 + 5,3 mmHg, P=0,04). A relação diurna:noturna da pressão sangüínea diastólica foi mais alta em pacientes DMDI com hiperfiltração (92,0 + 8,6%) quando comparada a mesma relação dos pacientes DMDI com normofiltração (85,9 + 4,8%) e controles (87,0 + 6,8%, P=0,02). Os pacientes DMDI apresentaram uma taxa de filtração glomerular significativamente correlacionada com a relação diurna:noturna de pressão diastólica (r=0,5, P=0,002), com o volume extracelular (r=0,4, P=0,002), e com HbA1 (r=0,3, P=0,03). Na análise de regressão múltipla escalonada, os fatores associados com a taxa de filtração glomerular foram: relação diurna:noturna de pressão sangüinea diastólica, volume extracelular, e HbA1 (ajustado r2=0,27, P=0,003). CONCLUSÕES: Hiperfiltração glomerular está associada à pressão sangüínea diastólica noturna elevada e a uma diminuição noturna abrupta dos níveis de pressão sangüínea diastólica em pacientes normotensivos e em pacientes DMDI normoalbuminúricos

Regulation of Zn and Fe transporters by the GPC1 gene during early wheat monocarpic senescence

BACKGROUND: During wheat senescence, leaf components are degraded in a coordinated manner, releasing amino acids and micronutrients which are subsequently transported to the developing grain. We have previously shown that the simultaneous downregulation of Grain Protein Content (GPC) transcription factors, GPC1 and GPC2, greatly delays senescence and disrupts nutrient remobilization, and therefore provide a valuable entry point to identify genes involved in micronutrient transport to the wheat grain. RESULTS: We generated loss-of-function mutations for GPC1 and GPC2 in tetraploid wheat and showed in field trials that gpc1 mutants exhibit significant delays in senescence and reductions in grain Zn and Fe content, but that mutations in GPC2 had no significant effect on these traits. An RNA-seq study of these mutants at different time points showed a larger proportion of senescence-regulated genes among the GPC1 (64%) than among the GPC2 (37%) regulated genes. Combined, the two GPC genes regulate a subset (21.2%) of the senescence-regulated genes, 76.1% of which are upregulated at 12 days after anthesis, before the appearance of any visible signs of senescence. Taken together, these results demonstrate that GPC1 is a key regulator of nutrient remobilization which acts predominantly during the early stages of senescence. Genes upregulated at this stage include transporters from the ZIP and YSL gene families, which facilitate Zn and Fe export from the cytoplasm to the phloem, and genes involved in the biosynthesis of chelators that facilitate the phloem-based transport of these nutrients to the grains. CONCLUSIONS: This study provides an overview of the transport mechanisms activated in the wheat flag leaf during monocarpic senescence. It also identifies promising targets to improve nutrient remobilization to the wheat grain, which can help mitigate Zn and Fe deficiencies that afflict many regions of the developing world.Fil: Pearce, Stephen. University of California; Estados UnidosFil: Tabbita, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; ArgentinaFil: Cantu, Dario. University of California; Estados UnidosFil: Buffalo, Vince. University of California; Estados UnidosFil: Avni, Raz. Tel Aviv University; IsraelFil: Vazquez Gross, Hans. University of California; Estados UnidosFil: Zhao, Rongrong. China Agricultural University; ChinaFil: Conley, Christopher J.. University of California; Estados UnidosFil: Distelfeld, Assaf. Faculty Of Life Sciences, Department Of Molecular Biolo;Fil: Dubcovsky, Jorge. University of California; Estados Unidos. Howard Hughes Medical Institute ; Estados Unidos. Gordon & Betty Moore Foundation Investigator; Estados Unido

CONDUTA TERAPÊUTICA NA HIPERTENSÃO ARTERIAL, NAS DISLIPIDEMIAS E NA OBESIDADE EM PACIENTES DIABÉTICOS

The main death cause in diabetic patients is cardiovascular disease. Atherosclerosis in these patients is more extense and involves a greater number of vessels, probably due to the simultaneous presence of several risk factors and hyperglycemia itself. In this paper, we review the diagnosis and treatment of several risk factors often found in type 2 diabetic patients: arterial hypertension, dyslipidemia and obesity. Arterial hypertension is present in about 50% of the patients and the recommended ideal blood pressure levels are below 130x80 mm of Hg. In order to achieve this goal, it is usually necessary to employ 2 or 3 antihypertensive agents. Particularly useful drugs are: angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, beta-blockers or thiazide diuretics. Obesity involves the majority of type 2 patients and a weight reduction such as 10 kg is associated to a significant improvement in glycemic, pressoric and lipidic profile. Anti-obesity drugs like orlistat and sibutramine are safe and when associated to life style changes can promote a 6% to 10% weight reduction. In patients with morbid obesity and no response to these agents, prescription of one of the several kinds of bariatric surgery should be considered. Dyslipidemia, characterized by elevated serum triglycerides and low HDL cholesterol levels, is typically present in diabetic patients, who also frequently show high serum LDL. To reach the recommended levels of LDL (&lt; 100 mg/ dl), the majority of patients will need to use statins. Some patients with persistent hypertriglyceridemia despite initial dietary treatment, will require a fibric acid prescription. The treatment of the several risk factors in diabetic patients, associated with the use of cardioprotective drugs (aspirin, converting enzymeinhibitors and beta-blockers) can reduce cardiovascular risk in 80%.&nbsp;A principal causa de morte dos pacientes diabéticos é a doença cardiovascular. A aterosclerose em pacientes diabéticos é mais extensa e afeta mais vasos devido provavelmente à presença de vários fatores de risco e à hiperglicemia per se. Neste trabalho são abordados o diagnóstico e tratamento de fatores de risco freqüentemente encontrados nos pacientes com diabetes tipo 2: hipertensão arterial, dislipidemia e obesidade. A hipertensão arterial ocorre em aproximadamente 50% dos pacientes diabéticos e idealmente deve-se atingir níveis pressóricos menores do que 130/80 mm de Hg. Para isto, usualmente é necessário o emprego de 2 a 3 agentes anti-hipertensivos. As classes de medicamentos que mostraram ser particularmente benéficas em pacientes diabéticos hipertensos são: inibidores da enzima conversora ou bloqueadores da angiotensina II, beta-bloqueadores e diuréticos tiazídicos. A obesidade é encontrada na maioria dos pacientes com diabetes tipo 2 e a redução de 10 kg determina uma melhora significativa nos níveis glicêmicos, lipídicos e pressóricos. O uso de medicamentos anti-obesidade, como o orlistat, e a sibutramina são seguros, e quando associados a mudanças do estilo de vida podem determinar reduções de peso (em média) de 6% a 10%. Em pacientes com obesidade mórbida e que não apresentaram resposta satisfatória a estes agentes, pode-se empregar as diversas modalidades de cirurgia bariátrica. Dislipidemia, caracterizada por elevação dos níveis séricos de triglicerídeos e diminuição do HDL, é característica dos pacientes diabéticos, que apresentam também freqüentemente níveis elevados de LDL colesterol. Para obter os níveis desejáveis de LDL colesterol (&lt;100 mg/dl), a maioria dos pacientes vai necessitar oemprego de uma estatina. Alguns pacientes com hipertrigliceridemia persistente apesar das medidas gerais, podem necessitar de um derivado do ácido fíbrico. O tratamento dos diversos fatores de risco nos pacientes diabéticos associados a uso de medicamentos com proteção cardiovascular (aspirina, inibidoresda enzima conversora e beta-bloqueadores) pode determinar uma redução de até 80% do risco cardiovascular

Dilatação térmica linear de refratários silico-aluminosos nacionais

No presente trabalho é determinada a dilatação térmica linear reversivel de alguns refratários sílico-aluminosos nacionais, notadamente dos produzidos pelas indústrias de refratários do Estado do Rio Grande do Sul (Brasil), utilizando um dilatômetro de precisão com registro fotográfico da curva de dilatação. São assim tornados públicos dados até então não conhecidos sôbre refratários nacionais, permitindo melhor avaliar o comportamento dos refratários produzidos pela indústia regionaL São reproduzidas igualmente as curvas de dilatação térmica dos refratários ensaios.In this paper the thermal expansion of Brazilian fire-clay bricks is determined, principally of those produced by refractory plants located in Rio Grande do Sul (Brazil), utilizing a precision dilatometer with photographic record of expansion curves. Thus are published unknown data about several native refractory products making possible a better knowledge of their behaviour in service. The paper also reproduces the expansion curves of the refractories tested.Die vorstehende Arbeit befasst sich mit der Bestimmung des Warmeausdehnungskoeffizienten einiger brasilianischer Schamottesteine, hauptsächlich derjenigen, die im Staate Rio Grande do Sul hergestellt werden, unter Benutzung eines Prazisionsdilatometers mit photographischer Registrierung. Es werden hiermit Daten veröffentlicht, die bisher un bekannt waren und die es ermõglichen, eine besser Kenntnis des Verhaltens einheimischer Schamottesteine im Betriebe zu gewinnen. Der Artikel bringt ausserdem die Ausdehnungskurven der untersuchten Schamottesteine