Observation of thermally-induced magnetic relaxation in a magnetite grain using off-axis electron holography

A synthetic basalt comprising magnetic Fe3O4 grains (~ 50 nm to ~ 500 nm in diameter) is investigated using a range of complementary nano-characterisation techniques. Off-axis electron holography combined with in situ heating allowed for the visualisation of the thermally-induced magnetic relaxation of an Fe3O4 grain (~ 300 nm) from an irregular domain state into a vortex state at 550˚C, just below its Curie temperature, with the magnetic intensity of the vortex increasing on cooling

An Unexpected Association in a Patient with Heart Failure Presenting a Surgical Challenge

Bicuspid aortic valve (BAV) is the most common form of congenital heart disease and frequently leads to premature valvular dysfunction. BAV is associated with aortic wall abnormalities and a high prevalence of ascending aorta dilatation and coarctation of the aorta (CoA). Consequently, in patients with BAV a careful assessment of the valve, and also of the aortic root and the ascending aorta, should be performed. The most feared complication is aortic dissection, however, the actual incidence of this complication is low. We report the case of a 58-year-old man who presented with New York Heart Association class III heart failure. The work-up revealed BAV with severe stenosis and severe compromise of left ventricle systolic function. In addition, CoA in the isthmus region, and type B dissection of the aorta were diagnosed.info:eu-repo/semantics/publishedVersio

Apocynin Dietary Supplementation Delays Mouse Ovarian Ageing

Advanced maternal age is associated with higher infertility rates, pregnancy-associated complications, and progeny health issues. The ovary is considered the main responsible for these consequences due to a continuous decay in follicle number and oocyte quality. Intracellular imbalance between oxidant molecules and antioxidant mechanisms, in favour of the former, results in oxidative stress (OS) that is believed to contribute to ovarian ageing. This work is aimed at evaluating whether an age-related increase in ovarian OS, inflammation, and fibrosis may contribute to tissue dysfunction and whether specific antioxidant supplementation with a NADPH oxidase inhibitor (apocynin) could ameliorate them. Mice aged 8-12 weeks (reproductively young) or 38-42 weeks (reproductively aged) were employed. Aged mice were divided into two groups, with one receiving apocynin (5 mM) in the drinking water, for 7 weeks, upon which animals were sacrificed and their ovaries collected. Ovarian structure was similar at both ages, but the ovaries from reproductively aged mice exhibited lipofuscin deposition, enhanced fibrosis, and a significant age-related reduction in primordial and primary follicle number when compared to younger animals. Protein carbonylation and nitration, and markers of OS were significantly increased with age. Moreover, mRNA levels of inflammation markers, collagens, metalloproteinases (MMPs), and tissue inhibitor MMPs (TIMPs) were upregulated. Expression of the antifibrotic miRNA29c-3p was significantly reduced. Apocynin supplementation ameliorated most of the age-related observed changes, sometimes to values similar to those observed in young females. These findings indicate that there is an age-related increase in OS that plays an important role in enhancing inflammation and collagen deposition, contributing to a decline in female fertility. Apocynin supplementation suggests that the imbalance can be ameliorated and thus delay ovarian ageing harmful effects.info:eu-repo/semantics/publishedVersio

a qualitative approach

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Visualized effect of oxidation on magnetic recording fidelity in pseudo-single-domain magnetite particles

Magnetite (​Fe3O4) is an important magnetic mineral to Earth scientists, as it carries the dominant magnetic signature in rocks, and the understanding of its magnetic recording fidelity provides a critical tool in the field of palaeomagnetism. However, reliable interpretation of the recording fidelity of ​Fe3O4 particles is greatly diminished over time by progressive oxidation to less magnetic iron oxides, such as maghemite (γ-Fe2O3), with consequent alteration of remanent magnetization potentially having important geological significance. Here we use the complementary techniques of environmental transmission electron microscopy and off-axis electron holography to induce and visualize the effects of oxidation on the magnetization of individual nanoscale ​Fe3O4 particles as they transform towards γ-Fe2O3. Magnetic induction maps demonstrate a change in both strength and direction of remanent magnetization within ​Fe3O4 particles in the size range dominant in rocks, confirming that oxidation can modify the original stored magnetic information

Upturn in secondary forest clearing buffers primary forest loss in the Brazilian Amazon

Brazil contains two-thirds of remaining Amazonian rainforests and is responsible for the most Amazon forest loss. Primary forest loss in the Brazilian Amazon has declined considerably since 2004 but secondary forest loss has never been quantified. We use a recently developed high-resolution land use/land cover dataset to track secondary forests in the Brazilian Amazon over 14 yr, providing the first estimates of secondary forest loss for the region. We find that secondary forest loss increased by (187 ± 48)% from 2008 to 2014. Moreover, the proportion of total forest loss accounted for by secondary forests rose from (37 ± 3)% in 2000 to (72 ± 5)% in 2014. The recent acceleration in secondary forests loss occurred across the entire region and was not driven simply by increasing secondary forest area but probably a conscious preferential shift towards clearance of a little-protected forest ecosystem (secondary forests). Our results suggest that secondary forests loss has eased deforestation pressure on primary forests. However, this has been at the expense of a lost carbon sequestration opportunity of 2.59–2.66 Pg C over our study period

Effect of intraperitioneally administered hydrolyzed whey protein on blood pressure and renal sodium handling in awake spontaneously hypertensive rats

The present study evaluated the acute effect of the intraperitoneal. (ip) administration of a whey protein hydrolysate (WPH) on systolic arterial blood pressure (SBP) and renal sodium handling by conscious spontaneously hypertensive rats (SHR). The ip administration of WPH in a volume of 1 ml dose-dependently lowered the SBP in SHR 2 h after administration at doses of 0.5 g/kg (0.15 M NaCl: 188.5 +/- 9.3 mmHg vs WPH: 176.6 +/- 4.9 mmHg, N = 8, P = 0.001) and 1.0 g/kg (0.15 M NaCl: 188.5 9.3 mmHg vs WPH: 163.8 +/- 5.9 mmHg, N = 8, P = 0.0018). Creatinine clearance decreased significantly (P = 0.0084) in the WPH-treated group (326 +/- 67 mu L min(-1) 100 g body weight(-1)) compared to 0.15 M NaCl-treated (890 26 mu L min(-1) 100 g body weight(-1)) and captopril-treated (903 +/- 72 mu L min(-1) 100 g body weight(-1)) rats. The ip administration of 1.0 g WPH/kg also decreased fractional sodium excretion to 0.021 +/- 0.019% compared to 0.126 +/- 0.041 and 0.66 +/- 0.015% in 0.15 M NaCl and captopril-treated rats, respectively (P = 0.033). Similarly, the fractional potassium excretion in WPH-treated rats (0.25 +/- 0.05%) was significantly lower (P = 0.0063) than in control (0.91 +/- 0.15%) and captopril-treated rats (1.24 +/- 0.30%), respectively. The present study shows a decreased SBP in SHR after the administration of WPH associated with a rise in tubule sodium reabsorption despite an angiotensin I-converting enzyme (ACE)-inhibiting in vitro activity (IC50 = 0.68 mg/mL). The present findings suggest a pathway involving ACE inhibition but measurements of plasma ACE activity and angiotensin Id levels are needed to support this suggestion.38121817182