Luminosity is a measure of the colliding frequency between beam and target and it is a crucial parameter for the measurement of absolute values, such as reaction cross sections. In this paper, we ...make use of experimental data from the ESR storage ring to demonstrate that the luminosity can be precisely determined by modelling the measured Rutherford scattering distribution. The obtained results are in good agreement with an independent measurement based on the x-ray normalization method. Our new method provides an alternative way to precisely measure the luminosity in low-energy stored-beam configurations. This can be of great value in particular in dedicated low-energy storage rings where established methods are difficult or impossible to apply.
Acute and chronic inflammatory states are associated with many changes in intracellular iron metabolism including sequestration of iron in the mononuclear-phagocyte system (MPS) and a decline in ...serum iron. Previous work in rodent models of acute inflammation has demonstrated inflammation-induced downregulation of intestinal and MPS iron exporter, ferroportin 1, mRNA and protein. In addition, these models have also demonstrated hepatic induction of mRNA of the small 25 amino acid peptide hepcidin. Hepcidin has been hypothesized to be the mediator of iron- and inflammation-induced changes in iron metabolism. The molecular details of the connection between iron metabolism, hepcidin and inflammation have become clearer with the recent finding of hepcidin-induced internalization and degradation of FPN1. The work presented here demonstrates that the lipopolysaccharide-induced splenic macrophage FPN1 mRNA downregulation is not dependent upon the action of a single cytokine such as IL-6, IL-1 or TNF-α because mice deficient in these pathways downregulate FPN1 normally. Furthermore, hepcidin is also synthesized in the spleen of normal mice and induced by lipopolysaccharide. Additionally, in vitro, splenic adherent cells produce hepcidin in response to lipopolysaccharide in an IL-6-dependent manner. There appear to be both probable transcriptional and post-transcriptional control of FPN1 expression by lipopolysaccharide-induced inflammation. The former effect is on mRNA expression and is independent of hepcidin, whereas the latter is IL-6- and hepcidin-dependent.
Abstract
SNCA, the first gene associated with Parkinson’s disease, encodes the α-synuclein protein, the predominant component within pathological inclusions termed Lewy bodies. The presence of Lewy ...bodies is one of the classical hallmarks found in the brain of patients with Parkinson’s disease, and Lewy bodies have also been observed in patients with other synucleinopathies. However, the study of α-synuclein pathology in cells has relied largely on two-dimensional culture models, which typically lack the cellular diversity and complex spatial environment found in the brain. Here, to address this gap, we use three-dimensional midbrain organoids, differentiated from human-induced pluripotent stem cells derived from patients carrying a triplication of the SNCA gene and from CRISPR/Cas9 corrected isogenic control iPSCs. These human midbrain organoids recapitulate key features of α-synuclein pathology observed in the brains of patients with synucleinopathies. In particular, we find that SNCA triplication human midbrain organoids express elevated levels of α-synuclein and exhibit an age-dependent increase in α-synuclein aggregation, manifested by the presence of both oligomeric and phosphorylated forms of α-synuclein. These phosphorylated α-synuclein aggregates were found in both neurons and glial cells and their time-dependent accumulation correlated with a selective reduction in dopaminergic neuron numbers. Thus, human midbrain organoids from patients carrying SNCA gene multiplication can reliably model key pathological features of Parkinson’s disease and provide a powerful system to study the pathogenesis of synucleinopathies.
Mohamed et al. investigate synucleinopathy in human midbrain organoids, derived from patients carrying a triplication of the SNCA gene. Human midbrain organoids recapitulate pathology observed in the brains of patients: an elevated level of α-synuclein, an age-dependent increase in aggregation and a selective reduction in dopaminergic neurons.
Graphical Abstract
Graphical Abstract
A
bstract
A search is presented for the lepton flavour violating decay
B
+
→
K
+
μ
−
τ
+
using a sample of proton-proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the ...LHCb detector and corresponding to a total integrated luminosity of 9 fb
−
1
. The
τ
leptons are selected inclusively, primarily via decays with a single charged particle. The four-momentum of the
τ
lepton is determined by using
B
+
mesons from
B
s
2
∗
0
→
B
+
K
−
decays. No significant excess is observed, and an upper limit is set on the branching fraction
ℬ(
B
+
→
K
+
μ
−
τ
+
) < 3.9 × 10
−5
at 90 % confidence level.
The obtained limit is comparable to the world-best limit.
Soybean (Glycine max) is one of the most important crop plants for seed protein and oil content, and for its capacity to fix atmospheric nitrogen through symbioses with soil-borne microorganisms. We ...sequenced the 1.1-gigabase genome by a whole-genome shotgun approach and integrated it with physical and high-density genetic maps to create a chromosome-scale draft sequence assembly. We predict 46,430 protein-coding genes, 70% more than Arabidopsis and similar to the poplar genome which, like soybean, is an ancient polyploid (palaeopolyploid). About 78% of the predicted genes occur in chromosome ends, which comprise less than one-half of the genome but account for nearly all of the genetic recombination. Genome duplications occurred at approximately 59 and 13 million years ago, resulting in a highly duplicated genome with nearly 75% of the genes present in multiple copies. The two duplication events were followed by gene diversification and loss, and numerous chromosome rearrangements. An accurate soybean genome sequence will facilitate the identification of the genetic basis of many soybean traits, and accelerate the creation of improved soybean varieties.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Iron nanoparticles (FeNPs) have been successfully prepared by high-energy ball milling in air for various milling times from 1 h to 32 h. Their structure, particle size, elemental composition, ...magnetic, and inductive heating properties were investigated by means of x-ray diffraction (XRD) analysis, field-emission scanning electron microscopy, energy-dispersive x-ray (EDX) spectroscopy, vibrating-sample magnetometry, and magnetic induction heating, respectively. XRD analysis showed that the average crystallite size decreased to 11 nm after 10 h of milling, then remained almost unchanged for longer milling times. Coexistence of iron (Fe) and iron oxide (FeO) phases was detected after 12 h of milling. EDX analysis also confirmed the occurrence of oxidation, which can be reconciled with the corresponding decrease and increase in saturation magnetization (
M
s
) with milling time when exposed to oxygen and when annealed under H
2
ambient due to oxygen reduction. The time-dependent magnetic and inductive heating responses of the FeNPs were investigated for prospective application in magnetic hyperthermia. The effect of varying the alternating-current (AC) magnetic field strength on the saturation heating temperature and specific loss power of FeNP-containing ferrofluid with concentration of 4 mg/mL was also studied and is discussed.
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