The requirement of the trace element selenium for life and its beneficial role in human health has been known for several decades. This is attributed to low molecular weight selenium compounds, as ...well as to its presence within at least 25 proteins, named selenoproteins, in the form of the amino acid selenocysteine (Sec). Incorporation of Sec into selenoproteins employs a unique mechanism that involves decoding of the UGA codon. This process requires multiple features such as the selenocysteine insertion sequence (SECIS) element and several protein factors including a specific elongation factor EFSec and the SECIS binding protein 2, SBP2. The function of most selenoproteins is currently unknown; however, thioredoxin reductases (TrxR), glutathione peroxidases (GPx) and thyroid hormone deiodinases (DIO) are well characterised selenoproteins involved in redox regulation of intracellular signalling, redox homeostasis and thyroid hormone metabolism. Recent evidence points to a role for selenium compounds as well as selenoproteins in the prevention of some forms of cancer. A number of clinical trials are either underway or being planned to examine the effects of selenium on cancer incidence. In this review we describe some of the recent progress in our understanding of the mechanism of selenoprotein synthesis, the role of selenoproteins in human health and disease and the therapeutic potential of some of these proteins.
A list of 11 newly collected and identified poronotic oribatids from Kenya is presented. Six of these represent new species or subspecies, belonging to the families Micreremidae, Oribatellidae, ...Oribatulidae, Haplozetidae and Scheloribatidae. The relationships of Semischeloribates Hammer 1973 are discussed.
Neutrinos emitted in the carbon, nitrogen, oxygen (CNO) fusion cycle in the Sun are a sub-dominant, yet crucial component of solar neutrinos whose flux has not been measured yet. The Borexino ...experiment at the Laboratori Nazionali del Gran Sasso (Italy) has a unique opportunity to detect them directly thanks to the detector’s radiopurity and the precise understanding of the detector backgrounds. We discuss the sensitivity of Borexino to CNO neutrinos, which is based on the strategies we adopted to constrain the rates of the two most relevant background sources,
pep
neutrinos from the solar
pp
-chain and
210
Bi beta decays originating in the intrinsic contamination of the liquid scintillator with
210
Pb. Assuming the CNO flux predicted by the high-metallicity Standard Solar Model and an exposure of 1000 days
×
71.3 t, Borexino has a median sensitivity to CNO neutrino higher than 3
σ
. With the same hypothesis the expected experimental uncertainty on the CNO neutrino flux is 23%, provided the uncertainty on the independent estimate of the
210
Bi
interaction rate is 1.5
cpd
/
100
ton
. Finally, we evaluated the expected uncertainty of the C and N abundances and the expected discrimination significance between the high and low metallicity Standard Solar Models (HZ and LZ) with future more precise measurement of the CNO solar neutrino flux.
Background: Disordered breathing among patients with panic disorder, including hyperventilation during attacks and increased anxiogenic response to carbon dioxide (CO
2) inhalation, is well ...established. We wished to assess whether there is a change in the physiological response to CO
2 after patients have undergone antipanic therapy with either tricyclic antidepressants or cognitive behavioral therapy (CBT).
Methods: Twenty-nine patients with panic disorder underwent baseline CO
2 sensitivity testing using the traditional Read rebreathing method and then received either antidepressant treatment (
n = 21) or CBT (
n = 8). After completing treatment, CO
2 testing was repeated. A comparison sample of 14 normal volunteers also had two CO
2 sensitivity tests, separated by an average of 21.6 (SD = 8.8) weeks.
Results: Using a liberal standard, in which all CO
2 sensitivity tests whose correlations between minute ventilation and end-tidal CO
2 were at least .75 were used, patients, but not controls, demonstrated a significant reduction in CO
2 sensitivity between the first and second test. Using a more conservative .90 correlation standard reduced the sample size available and resulted in trend reduction in patients but no significant change in controls. There was a suggestion that the change was most pronounced in treatment responders, although the number of patient nonresponders is extremely small in this sample.
Conclusions: These data indicate that treatment reduces CO
2 sensitivity in patients with panic disorder. We speculate that manipulation of the serotonergic and noradrenergic neurotransmission systems, both known to play a role in the control of respiration, may have a specific effect in reducing respiratory hyperactivity in panic disorder.
A
bstract
The Borexino detector measures solar neutrino fluxes via neutrino-electron elastic scattering. Observed spectra are determined by the solar-
ν
e
survival probability
P
ee
(
E
), and the ...chiral couplings of the neutrino and electron. Some theories of physics beyond the Standard Model postulate the existence of Non-Standard Interactions (NSI’s) which modify the chiral couplings and
P
ee
(
E
). In this paper, we search for such NSI’s, in particular, flavor-diagonal neutral current interactions that modify the
ν
e
e
and
ν
τ
e
couplings using Borexino Phase II data. Standard Solar Model predictions of the solar neutrino fluxes for both high- and low-metallicity assumptions are considered. No indication of new physics is found at the level of sensitivity of the detector and constraints on the parameters of the NSI’s are placed. In addition, with the same dataset the value of sin
2
θ
W
is obtained with a precision comparable to that achieved in reactor antineutrino experiments
.
An ECG showed regular rhythm with a pattern similar to those described in the Brugada syndrome (below left, panel A: right bundle branch block (RBBB) pattern with coved ST segment elevation in leads ...V1-V3).
Observation of geo-neutrinos Bellini, G.; Benziger, J.; Bonetti, S. ...
Physics letters. B,
04/2010, Volume:
687, Issue:
4-5
Journal Article
Peer reviewed
Open access
Geo-neutrinos, electron anti-neutrinos produced in β decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet's interior. We report the first ...observation at more than 3σ C.L. of geo-neutrinos, performed with the Borexino detector at Laboratori Nazionali del Gran Sasso. Anti-neutrinos are detected through the neutron inverse β decay reaction. With a 252.6 ton yr fiducial exposure after all selection cuts, we detected 9.9+4.1−3.4(+14.6−8.2) geo-neutrino events, with errors corresponding to a 68.3% (99.73%) C.L. From the lnL profile, the statistical significance of the Borexino geo-neutrino observation corresponds to a 99.997% C.L.
Our measurement of the geo-neutrinos rate is 3.9+1.6−1.3(+5.8−3.2) events/(100 ton yr).
The observed prompt positron spectrum above 2.6 MeV is compatible with that expected from European nuclear reactors (mean base line of approximately 1000 km). Our measurement of reactor anti-neutrinos excludes the non-oscillation hypothesis at 99.60% C.L. This measurement rejects the hypothesis of an active geo-reactor in the Earth's core with a power above 3 TW at 95% C.L.
There is a substantial body of literature demonstrating that stimulation of respiration (hyperventilation) is a common event in panic disorder patients during panic attack episodes. Further, a number ...of abnormalities in respiration, such as enhanced CO
2 sensitivity, have been detected in panic patients. This led some to posit that there is a fundamental abnormality in the physiological mechanisms that control breathing in panic disorder and that this abnormality is central to illness etiology. More recently, however, evidence has accumulated suggesting that respiratory physiology is normal in panic patients and that their tendency to hyperventilate and to react with panic to respiratory stimulants like CO
2 represents the triggering of a hypersensitive fear network. The fear network anatomy is taken from preclinical studies that have identified the brain pathways that subserve the acquisition and maintenance of conditioned fear. Included are the amygdala and its brain stem projections, the hippocampus, and the medial prefrontal cortex. Although attempts to image this system in patients during panic attacks have been difficult, the theory that the fear network is operative and hyperactive in panic patients explains why both medication and psychosocial therapies are clearly effective. Studies of respiration in panic disorder are an excellent example of the way in which peripheral markers have guided researchers in developing a more complete picture of the neural events that occur in psychopathological states.
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