The soluble transferrin receptor as a marker of iron homeostasis in normal subjects and in HFE-related hemochromatosis

Background and Objectives. The soluble transferrin receptor (sTfR) is a clinical marker of erythropoietic activity, also used in the diagnosis of iron deficiency. In the present paper we explore the meaning of this parameter in normal physiological conditions of iron homeostasis and in the setting of iron overload due to hereditary hemochromatosis (HH). Design and Methods. Reference values for sTfR were established in a population of 42 apparently healthy subjects, analyzed in relation to other hematologic parameters, namely, hemoglobin (Hb), mean corpuscular volume (MCV), transferrin saturation (TfSat) and serum ferritin. The same analysis was done in a group of 45 patients with HH who were homozygous for the C282Y mutation of HFE and had a wide range of TfSat values. In addition, individual serial profiles were analyzed in three patients. Results. In normal subjects circulating sTfR correlated significantly with the TfSat level, reflecting the systemic effect of iron availability on the erythropoietic activity in a normal physiological steady state. A TfSat of 25% appeared as a threshold value, below which there was a progressive increase in sTfR; this increase in sTfR occurred concomitantly with a decrease in Hb, MCV and serum ferritin. In HH patients the up-regulation of sTfR started at TfSat values as high as 50%. Interpretation and Conclusions. The fact that sTfR up-regulation started at higher TfSat values in HH patients suggests that the recognition of systemic iron available for erythropoiesis is altered in this condition. Based on these results, a new hypothesis is advanced, proposing that the HFE protein in involved as a sensor of systemic iron availability, via the soluble transferrin receptor

Disorder Averaging and Finite Size Scaling

We propose a new picture of the renormalization group (RG) approach in the presence of disorder, which considers the RG trajectories of each random sample (realization) separately instead of the usual renormalization of the averaged free energy. The main consequence of the theory is that the average over randomness has to be taken after finding the critical point of each realization. To demonstrate these concepts, we study the finite-size scaling properties of the two-dimensional random-bond Ising model. We find that most of the previously observed finite-size corrections are due to the sample-to-sample fluctuation of the critical temperature and scaling is more adequate in terms of the new scaling variables.Comment: 4 pages, 6 figures include

Recomendação de inoculante para cultura de milho utilizando a bactéria Herbaspirillum seropedicae, estirpe BR11417

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Calibração do teste de tetrazólio em sementes de castanha-do-brasil.

bitstream/item/57744/1/CPATU-ComTec17.pd

The physical properties of Gd3Ru: a real candidate for a practical cryogenic refrigerator

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORThe magnetization, the specific heat, and the magnetocaloric effect (MCE) for Gd3Ru are presented as function of temperature at different magnetic fields. The results show a maximum entropy change -Delta S = 30 J/kg K @ 5 T, which is the highest value for the R3M compounds. With a non-hysteretic transition of first order type at T-C = 54 K, it presents a temperature change Delta T-max = 5.7K around 59K with a refrigerating cooling power of 700 J/kg and these results are comparable to values found for giant MCE materials. This compound is stable and able to operate at temperatures between 90K and 40K with a minimum -Delta S = 5 J/kg K. These figures were obtained by sweeping the magnetic field without using sample preparation routines. This methodology is appropriate to evaluate the MCE for the cycling process of a cryogenic magnetic refrigerator. (C) 2015 AIP Publishing LLC.The magnetization, the specific heat, and the magnetocaloric effect (MCE) for Gd3Ru are presented as function of temperature at different magnetic fields. The results show a maximum entropy change -Delta S = 30 J/kg K @ 5 T, which is the highest value for the R3M compounds. With a non-hysteretic transition of first order type at T-C = 54 K, it presents a temperature change Delta T-max = 5.7K around 59K with a refrigerating cooling power of 700 J/kg and these results are comparable to values found for giant MCE materials. This compound is stable and able to operate at temperatures between 90K and 40K with a minimum -Delta S = 5 J/kg K. These figures were obtained by sweeping the magnetic field without using sample preparation routines. This methodology is appropriate to evaluate the MCE for the cycling process of a cryogenic magnetic refrigerator.1061914FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORSem informaçãoSem informaçãoSem informaçãoThe authors thank Professor Lisandro Cardoso and Hugo Freitas for the X-Ray diffractograms and also Gustavo Lombardi for the assistance in the sample preparation. We acknowledge the financial support provided by the Brazilian agencies FAPESP, FAEPEX-Unicamp, CNPq, and CAPES

Effect of crosslinking in chitosan/aloe vera-based membranes for biomedical applications

The  positive  interaction  between  polysaccharides  with  active  phytochemicals found  in  medicinal  plants  may  represent  a  strategy  to  create  active  wound dressing  materials  useful  for  skin  repair.  In  the  present  work,  blended membranes  composed  of  chitosan  (Cht)  and  Aloe  vera  gel  were  prepared through the solvent casting, and were crosslinked with genipin to improve their properties. Topography, swelling, wettability, mechanical properties and in vitro cellular response of the membranes were investigated. With the incorporation of aloe  vera  gel  into  chitosan  solution,  the  developed  chitosan/aloe-based membranes  displayed  increased  roughness  and  wettability;  while  the  genipin crosslinking  promoted  the  formation  of  stiffer  membranes  in  comparison  to those  of  the  non-modified  membranes.  Moreover, in  vitro cell  culture  studies evidenced that the L929 cells have high cell viability, confirmed by MTS test and calcein-AM staining. The findings suggested that both blend compositions and crosslinking  affected  the  physico-chemical  properties  and  cellular  behavior  of the developed membranes.The authors acknowledge financial support from Portuguese Foundation for Science and Technology - FCT (Grant SFRH/BPD/45307/2008; SFRH/BD/64601/2009), "Fundo Social Europeu" - FSE, and "Programa Diferencial de Potencial Humano - POPH". This work was partially supported by the FEDER through POCTEP 0330_IBEROMARE_1_P

Rotating strings

Analytical expressions are provided for the configurations of an inextensible, flexible, twistable inertial string rotating rigidly about a fixed axis. Solutions with trivial radial dependence are helices of arbitrary radius and pitch. Non-helical solutions are governed by a cubic equation whose roots delimit permissible values of the squared radial coordinate. Only curves coplanar with the axis of rotation make contact with it.Comment: added to discussion and made small revisions to tex