Obesity-Related Oxidative Stress: the Impact of Physical Activity and Diet Manipulation

Obesity-related oxidative stress, the imbalance between pro-oxidants and antioxidants (e.g., nitric oxide), has been linked to metabolic and cardiovascular disease, including endothelial dysfunction and atherosclerosis. Reactive oxygen species (ROS) are essential for physiological functions including gene expression, cellular growth, infection defense, and modulating endothelial function. However, elevated ROS and/or diminished antioxidant capacity leading to oxidative stress can lead to dysfunction. Physical activity also results in an acute state of oxidative stress. However, it is likely that chronic physical activity provides a stimulus for favorable oxidative adaptations and enhanced physiological performance and physical health, although distinct responses between aerobic and anaerobic activities warrant further investigation. Studies support the benefits of dietary modification as well as exercise interventions in alleviating oxidative stress susceptibility. Since obese individuals tend to demonstrate elevated markers of oxidative stress, the implications for this population are significant. Therefore, in this review our aim is to discuss (i) the role of oxidative stress and inflammation as associated with obesity-related diseases, (ii) the potential concerns and benefits of exercise-mediated oxidative stress, and (iii) the advantageous role of dietary modification, including acute or chronic caloric restriction and vitamin D supplementation

Different complexation behaviour of a proton transfer compound obtained from pyridine-2,6-dicarboxylic acid and creatine with Tl(I), Cu(II), Fe(III), and Bi(III): synthesis, characterization, crystal structures and solution studies

The dif fer ent complexation meth ods of a pro ton trans fer com pound, (creatH)(pydcH)·H2O (pydcH2 = pyridine-2,6-di car box yl ic acid; creat = creatinine) with metal ions have been stud ied and for ma tion of [(Tl(pydcH)]n (1) , [(Fe(pydc)(H2O)2)2ox]·6H2O (2), [Cu(pydc)(pydcH2)]·2H2O (3) and (creatH)2[Bi(pydc)2]2·4H2O (4) are re ported. The char ac ter iza tion was per formed us ing IR spec tros copy and sin gle crys tal X-ray dif frac tion anal y sis. The Tl(I) com plex [(Tl(pydcH)]n (1) ob tained from (creatH)(pydcH)·H2O is a poly meric sys tem, show ing only the con tri bu tion of the an ionic spe cies of (creatH)(pydcH)·H2O to the complexation. The Fe(III) and the Cu(II) com plexes [(Fe(pydc)(H2O)2)2ox]·6H2O (2) (ox = ox a late) and [Cu(pydc)(pydcH2)]·2H2O (3) were also ob tained from (creatH)(pydcH)·H2O. The Bi(III) com plex (creatH)2[Bi(pydc)2]2·4H2O (4) is a dimeric sys tem, show ing both con tri bu tion of the cationic and an ionic frag ments. The com plexes 1–4 show a va ri ety of struc tural fea tures in clud ing mononuclear, binuclear, poly meric struc tures and un usual ligand for ma tion. In com pounds (1), (2), (3) and (4), a large num - ber of hy dro gen bonds are ob served. These in ter ac tions as well as p-p stack ing play an im por tant role in the for ma tion and sta bi li za tion of supra mo lecu lar sys tems in the crys tal lat tices. The stoichiometry and sta bil ity of the Cu(II), Tl(I) and Bi(III) com plexes with (pydc)(creat) and Fe(III) with pydc-ox mix ture in aque ous so lu tion were in ves ti gated by potentiometric pH ti tra tion

Decision error probability in a two-stage communication network for smart grids with imperfect links

Abstract This paper analyzes a scenario where the distribution system operator needs to estimate whether the average power demand in a given period is above a predetermined threshold using a 1-bit memoryless scheme. Specifically, individual smartmeters periodically monitor the average power demand of their respective households to inform the system operator if it is above a predetermined level using only a 1-bit signal. The communication link between the meters and the operator occurs in two hops and is modeled as binary symmetric channels. The first hop connects individual smart meters to their corresponding aggregator, while the second connects different aggregators to the system operator. A decision about the power demand also happens in two stages based on the received information bit. We consider here three decision rules: AND, OR and MAJORITY. Our analytical results indicate the circumstances (i.e. how frequent the meters experience the consumption above the defined threshold) and the design setting (i.e. decision rules) that a low error probability can be attained. We illustrate our approach with numerical results from actual daily consumptions from 12 households and 3 aggregators

The effect of the B-site cation and oxygen stoichiometry on the local and average crystal and magnetic structures of Sr2Fe1.9M0.1O5+y (M = Mn, Cr, Co; y = 0, 0.5)

Six compounds with formula Sr\u2082Fe\u2081.\u2089M\u2080.\u2081O\u2085+y (M = Mn, Cr, Co; y = 0, 0.5) were synthesized in air and argon, exhibiting surprisingly different properties depending on the B-cation type in spite of the low (5%) doping level. All argon synthesized phases, y 0, have long range brownmillerite ordering of oxygen vacancies with Icmm symmetry as shown by neutron diffraction (ND). All show long-range G-type antiferromagnetic order with N\ue9el temperatures, TN, from variable temperature ND of 649(3)K, 636(2)K and 668(5)K for Cr, Mn and Co-compounds, respectively, compared with Sr\u2082Fe\u2082O\u2085, TN = 693 K. Competing ferromagnetic interactions may be responsible for the anomalously low value in the M = Mn case. The air synthesized phases with y ~ 0.5 show surprising variation with M as investigated by X-ray, TOF and constant wavelength neutron diffractions. The M = Co compound is isostructural with Sr\u2084Fe\u2084O\u2081\u2081 (Sr\u2082Fe\u2082O\u2085.\u2085), Cmmm, while the M = Cr phase is cubic, Pm-3m, and that for M = Mn appears to be cubic but the reflections are systematically broadened in a manner which suggests a local Cmmm structure. NPDF studies show that the local structure of the Cr phase is better described in terms of a Cmmm ordering of oxygen vacancies with Fe\u2013O coordination numbers of five and six. The M = Co material shows C-type antiferromagnetic long-range magnetic order at 4 K as found for Sr\u2084Fe\u2084O\u2081\u2081. TN 230 K is inferred from a ZFC-FC magnetic susceptibility divergence compared with TN = 232 K for un-doped Sr4Fe4O11. The M = Cr and Mn compounds show no long-range magnetic ordering down to 4 K, but the divergence of ZFC and FC susceptibility data indicative of spin glass-like transitions occur at ~60 K and ~45 K for Cr and Mn, respectively. ND shows both diffuse and sharp Bragg magnetic reflections at positions consistent with a Cmmm cell for the M = Mn phase. For the M = Cr material, a very weak magnetic Bragg peak indexed as (1/2 1/2 1/2), consistent with a G-type AF order, is found at 4 K. These results rule out a spin glass-like ground state for both materials.Peer reviewed: YesNRC publication: Ye

Systematic study of compositional and synthetic control of vacancy and magnetic ordering in oxygen-deficient perovskites Ca2Fe2\u2013xMnxO5+y and CaSrFe2\u2013xMnxO5+y(x= 1/2, 2/3, and 1;y= 0\u20131/2)

Ten compounds belonging to the series of oxygen-deficient perovskite oxides Ca2Fe2\u2013xMnxO5 and CaSrFe2\u2013xMnxO5+y, where x = 1/2, 2/3, and 1 and y 48 0\u20130.5, were synthesized and investigated with respect to the ordering of oxygen vacancies on both local and long-range length scales and the effect on crystal structure and magnetic properties. For the set with y 48 0 the oxygen vacancies always order in the long-range sense to form the brownmillerite structure containing alternating layers of octahedrally and tetrahedrally coordinated cations. However, there is a change in symmetry from Pnma to Icmm upon substitution of Sr for one Ca for all x, indicating local Td chain (vacancy) disorder. In the special case of CaSrFeMnO5 the neutron diffraction peaks broaden, indicating only short-range structural order on a length scale of 160 \uc5. This reveals a systematic progression from Ca2FeMnO5 (Pnma, well-ordered tetrahedral chains) to CaSrFeMnO5 (Icmm, disordered tetrahedral chains, overall short-range order) to Sr2FeMnO5 (Pm3m, destruction of tetrahedral chains in a long-range sense). Systematic changes occur in the magnetic properties as well. While long-range antiferromagnetic order is preserved, the magnetic transition temperature, Tc, decreases for the same x when Sr substitutes for one Ca. A review of the changes in Tc for the series Ca2Fe2\u2013xMxO5, taking into account the tetrahedral/octahedral site preferences for the various M3+ ions, leads to a partial understanding of the origin of magnetic order in these materials in terms of a layered antiferromagnetic model. While in all cases the preferred magnetic moment direction is (010) at low temperatures, there is a cross over for x = 0.5 to (100) with increasing temperature for both the Ca2Fe2\u2013xMnxO5 and the CaSrFe2\u2013xMnxO5 series. For the y > 0 phases, while a brownmillerite ordering of oxygen vacancies is preserved for the Ca2 phases, a disordered Pm3m cubic perovskite structure is always found when Sr is substituted for one Ca. Long-range magnetic order is also lost, giving way to spin glass or cluster-glass-like behavior below 50 K. For the x = 0.5 phase, neutron pair distribution function (NPDF) studies show a local structure related to brownmillerite ordering of oxygen vacancies. Neutron diffraction data at 3.8 K show a broad magnetic feature, incommensurate with any multiple of the chemical lattice, and with a correlation length (magnetic domain) of 6.7(4) \uc5.Peer reviewed: YesNRC publication: Ye

Synthesis, Crystal Structure, and Magnetic Properties of Li₃Mg₂OsO₆, a Geometrically Frustrated Osmium(V) Oxide with an Ordered Rock Salt Structure: Comparison with Isostructural Li₃Mg₂RuO₆

The novel osmium-based oxide Li₃Mg₂OsO₆ was synthesized in polycrystalline form by reducing Li₅OsO₆ by osmium metal and osmium­(IV) oxide in the presence of stoichiometric amounts of magnesium oxide. The crystal structure was refined using powder X-ray diffraction data in the orthorhombic <i>Fddd</i> space group with <i>a</i> = 5.88982(5) Å, <i>b</i> = 8.46873(6) Å, and <i>c</i> = 17.6825(2) Å. This compound is isostructural and isoelectronic with the ruthenium-based system Li₃Mg₂RuO₆. The magnetic ion sublattice Os⁵⁺ (<i>S</i> = ³/₂) consists of chains of interconnected corner- and edge-shared triangles, which brings about the potential for geometric magnetic frustration. The Curie–Weiss law holds over the range 80–300 K with <i>C</i> = 1.42(3) emu·K/mol [μ_eff = 3.37(2) μ_B] and θ_C = −105.8(2) K. Below 80 K, there are three anomalies at 75, 30, and 8 K. Those at 75 and 30 K are suggestive of short-range antiferromagnetic correlations, while that at 8 K is a somewhat sharper maximum showing a zero-field-cooled/field-cooled divergence suggestive of perhaps spin freezing. The absence of magnetic Bragg peaks at 3.9 K in the neutron diffraction pattern supports this characterization, as does the absence of a sharp peak in the heat capacity, which instead shows only a very broad maximum at ∼12 K. A frustration index of <i>f</i> = 106/8 = 13 indicates a high degree of frustration. The magnetic properties of the osmium phase differ markedly from those of the isostructural ruthenium material, which shows long-range antiferromagnetic order below 17 K, <i>f</i> = 6, and no unusual features at higher temperatures. Estimates of the magnetic exchange interactions at the level of spin-dimer analysis for both the ruthenium and osmium materials support a more frustrated picture for the latter. Errors in the calculation and assignment of the exchange pathways in the previous report on Li₃Mg₂RuO₆ are identified and corrected