543 research outputs found

    Comparison of serum levels of hepcidin and pro-hepcidin in hemodialysis patients and healthy subjects

    Get PDF
    Hepcidin prevents absorption of iron from the intestine and inhibits release of iron from macrophages and hepatocytes. For this reason, it seems that high levels of hepcidin are a predisposing factor for anemia in chronic inflammatory conditions such as chronic kidney disease and dialysis patients. This study was designed to determine the role of changes in the level of serum hepcidin in the management of hemodialysis patients. This study included 44 dialysis patients and 44 controls. The hepcidin and pro-hepcidin levels were measured by the enzyme linked immunosorbent assay method. The serum ferritin level was measured by the chemiluminescence method. The mean hepcidin level was 999.3 ± 996.7 ng/mL in the case group and 770.4 ± 815.9 ng/mL in the control group (P = 0.25). The mean pro-hepcidin level was, respectively, 186.1 ± 220.3 pg/mL and 150.87 ± 207.7 pg/mL, in the case group and control groups (P = 0.45). The mean (standard deviation) ferritin level was 816.4 ± 379.4 ng/mL in the case group and 193 ± 171.8 ng/mL in the control group (P < 0.001). In the case group, the correlation between serum ferritin and hepcidin was not significant (r = 0.6, P = 0.08). Also, there was no significant correlation between serum ferritin and pro-hepcidin levels (r = 0.6, P = 0.08). A positive correlation was seen between pro-hepcidin and hepcidin levels (r = 0.92, P < 0.01). In this study, the results showed that the serum hepcidin levels are high in dialysis patients and that there was no correlation with the serum ferritin levels

    Accelerated-Cherenkov radiation and signatures of radiation reaction

    Full text link
    In this manuscript we examine an accelerated charged particle moving through an optical medium, and explore the emission of accelerated-Cherenkov radiation. The particle's reaction to acceleration creates a low-frequency spectral cutoff in the Cherenkov emission that has a sharp resonance at the superluminal threshold. Moreover, the effect of recoil on the radiation is incorporated kinematically through the use of an Unruh-DeWitt detector by setting an energy gap, i.e., the change in electron energy, to the recoil energy of the emitted photon. The simultaneous presence of recoil and acceleration conspire to produce a localized resonance peak in the emission. These theoretical considerations could be used to construct high precision tests of radiation reaction using Cherenkov emission under acceleration.Comment: 18 pages, 8 figures. As appears in The New Journal of Physic

    Efectos del fósforo de un efluente cloacal sobre la morfología interna y externa de Eichhornia crassipes (Mart. Solms) en un humedal artificial

    Get PDF
    Se compararon las variaciones morfológicas que presentó Eichhornia crassipes (Mart. Solms) a la entrada y salida de un humedal construido para tratar un efluente cloacal. Se determinó la concentración de fósforo en el agua y en las plantas. Se midió la altura de las plantas, la longitud de las raíces y la biomasa. Para estudiar la morfología interna de la raíz se calculó el área transversal de la raíz (ATR), de la médula (ATM) y de los vasos metaxilemáticos tardíos (ATV) y el área total del metaxilema (ATVt) por sección. Las diferentes concentraciones de fósforo presentes en el efluente cloacal, a la entrada y salida del humedal, produjeron variaciones en la morfología externa e interna de E. crassipes. La concentración de fósforo en los tejidos mostró una relación directa con la concentración de fósforo en el agua. En las plantas de la entrada se observó una mayor altura, menor longitud y biomasa de las raíces en comparación con las plantas de la salida. En las plantas de la entrada se observó un aumento de los valores de ATM y ATV y ATVt, comparadas con las plantas de la salida. La variación en los parámetros morfológicos internos se debió probablemente al aumento del área transversal de la raíz.The present study compares the morphological variation of Eichhornia crassipes (Mart. Solms) between the inlet and outlet zones of a wetland constructed for the treatment of a sewage effluent. The phosphorus concentration in water and plants was determined. Plant height, root length and dry biomass were measured. The areas of cross-sectional whole root (ATR), stele (ATM), large metaxylematic vessels (ATV) and the total metaxylematic vessels (ATVt) were calculated. The different phosphorus concentrations registered at the inlet and outlet zones of the constructed wetland, induced internal and external morphological changes in E. crassipes. Phosphorus concentration in tissues was positively correlated with phosphorus concentrations in water. The inlet zone plants were taller and they had shorter roots and less proportion of root dry weight in comparison with the outlet zone plants. The inlet zone plants increased the ATM, ATV and ATVt values, in comparison with the outlet zone plants. The variation in the internal morphological parameters was probably due to the increase of the cross-sectional whole root

    Pinpointing The Extent Of Electronic Delocalization In The Re(i)-to-tetrazine Charge-separated Excited State Using Time-resolved Infrared Spectroscopy

    Get PDF
    Femtosecond mid-IR transient absorption spectroscopy (TRIR) and time-dependent density functional theory (TD-DFT) calculations on Re(CO)(3)Cl(Me(2)BPTZ) [Me(2)BPTZ = 3,6-bis(5-methyl-2-pyridine)-1,2,4,5-tetrazine] are used to demonstrate that the lowest excited state of the complex is a triplet metal-to-ligand charge-transfer ((3)MLCT) state with a lifetime of 225 ps. The short excited-state lifetime is explained by the energy-gap taw. Vibrational cooling of the (3)MLCT state shows up as early-time dynamics (3.6 ps). The structural changes in the excited state are deduced from the frequency shifts in the TRIR vibrational bands. The vibrational frequencies of the CO groups increase upon excitation as a result of decreased back-bonding between the CO ligands and the oxidized Re center in the (3)MLCT state. The vibrational frequencies of the central tetrazine ring of Me(2)BPTZ decrease because of the decrease in the bond order upon reduction of the Me(2)BPTZ ligand in the (3)MLCT state. Interestingly, the TRIR signals from the pyridine moieties of Me2BPTZ were not detected. These results can be explained by localization of the electronic charge on the central tetrazine ring in the (3)MLCT state of Re(CO)(3)Cl(Me(2)BPTZ), as supported by TD-DFT calculations

    Superantigen as a Promising Immunotherapy Treatment against Cancer: A Review Article

    Get PDF
    Superantigens are toxins produced in hosts by some pathogenic microbes as a mechanism to sustain their pathogenicity. Superantigens are highly resistant to degradation by proteases enzyme, heat denaturation, and cause many dangerous diseases that in severe cases lead to death. Superantigens are atypical antigens that stimulate a profound proliferation of polyclonal T cells at low concentrations. All superantigens have a standard architecture even though they differ in amino acid sequences and are divided into two groups: endogenous superantigens and exogenous superantigens. The major histocompatibility complex molecules on antigen-presenting cells and T cell receptors on T cells are the major players in identifying foreign antigens. Superantigens can bind nonspecifically to both the major histocompatibility complex class II molecules and T cell receptors and form a trimolecular complex. Superantigens do not follow conventional antigens processing and presentation; they bind as intact macromolecules outside the antigen-binding groove of the major histocompatibility complex class II and to Vβ of T cells receptors. Thus, triggering an excessive release of proinflammatory cytokines, radiotherapy and chemotherapy often develop radio/drug resistance. Hence, cancer immunotherapy has been mainly considered as it instigates the patient’s immune system to fight cancer. Superantigens are one of the most potent T cell mitogens as 0.1 pg/ml is adequate to excite T lymphocytes. Accordingly, extensive in-vivo/in-vitro investigations have been conducted on the potential role of superantigens in eradicating tumors. The safety and effectiveness of superantigens as a cancer treatment have been verified in many clinical trials. Nevertheless, the vast inflammation after the potent T cell activation is known to promote diseases, including cancer. This paper reviews the potentiality of superantigen as an immunotherapy treatment against cancer
    corecore