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1.
Nature ; 587(7833): 210-213, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177669

RESUMO

Light elements were produced in the first few minutes of the Universe through a sequence of nuclear reactions known as Big Bang nucleosynthesis (BBN)1,2. Among the light elements produced during BBN1,2, deuterium is an excellent indicator of cosmological parameters because its abundance is highly sensitive to the primordial baryon density and also depends on the number of neutrino species permeating the early Universe. Although astronomical observations of primordial deuterium abundance have reached percent accuracy3, theoretical predictions4-6 based on BBN are hampered by large uncertainties on the cross-section of the deuterium burning D(p,γ)3He reaction. Here we show that our improved cross-sections of this reaction lead to BBN estimates of the baryon density at the 1.6 percent level, in excellent agreement with a recent analysis of the cosmic microwave background7. Improved cross-section data were obtained by exploiting the negligible cosmic-ray background deep underground at the Laboratory for Underground Nuclear Astrophysics (LUNA) of the Laboratori Nazionali del Gran Sasso (Italy)8,9. We bombarded a high-purity deuterium gas target10 with an intense proton beam from the LUNA 400-kilovolt accelerator11 and detected the γ-rays from the nuclear reaction under study with a high-purity germanium detector. Our experimental results settle the most uncertain nuclear physics input to BBN calculations and substantially improve the reliability of using primordial abundances to probe the physics of the early Universe.

2.
Phys Rev Lett ; 131(16): 162701, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37925687

RESUMO

The ^{12}C/^{13}C ratio is a significant indicator of nucleosynthesis and mixing processes during hydrogen burning in stars. Its value mainly depends on the relative rates of the ^{12}C(p,γ)^{13}N and ^{13}C(p,γ)^{14}N reactions. Both reactions have been studied at the Laboratory for Underground Nuclear Astrophysics (LUNA) in Italy down to the lowest energies to date (E_{c.m.}=60 keV) reaching for the first time the high energy tail of hydrogen burning in the shell of giant stars. Our cross sections, obtained with both prompt γ-ray detection and activation measurements, are the most precise to date with overall systematic uncertainties of 7%-8%. Compared with most of the literature, our results are systematically lower, by 25% for the ^{12}C(p,γ)^{13}N reaction and by 30% for ^{13}C(p,γ)^{14}N. We provide the most precise value up to now of 3.6±0.4 in the 20-140 MK range for the lowest possible ^{12}C/^{13}C ratio that can be produced during H burning in giant stars.

3.
Omega (Westport) ; : 302228231169541, 2023 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-37032309

RESUMO

Despite extensive efforts in a better understanding of associations between death anxiety and various factors, efforts studying the complex associations across those variables are still limited. This study was conducted to better understand the possible complexity between death anxiety and myriad of factors, by first extracting the most important features, and then assessing the complexity of variables by checking all pairwise interaction terms. We found most of associated factors of death anxiety are related to the concept of attachment or caring for loved ones. Ill-effect attachment with positive associations with death anxiety included factors such as attachment to the physical side of oneself, being alone before death, and the possibility of death being the end of us. On the other hand, supernatural conceptions of worldviews such as believing in God, believing that the soul is separate from body, and being religious buffer against the death anxiety.

4.
Phys Rev Lett ; 127(15): 152701, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34677992

RESUMO

One of the main neutron sources for the astrophysical s process is the reaction ^{13}C(α,n)^{16}O, taking place in thermally pulsing asymptotic giant branch stars at temperatures around 90 MK. To model the nucleosynthesis during this process the reaction cross section needs to be known in the 150-230 keV energy window (Gamow peak). At these sub-Coulomb energies, cross section direct measurements are severely affected by the low event rate, making us rely on input from indirect methods and extrapolations from higher-energy direct data. This leads to an uncertainty in the cross section at the relevant energies too high to reliably constrain the nuclear physics input to s-process calculations. We present the results from a new deep-underground measurement of ^{13}C(α,n)^{16}O, covering the energy range 230-300 keV, with drastically reduced uncertainties over previous measurements and for the first time providing data directly inside the s-process Gamow peak. Selected stellar models have been computed to estimate the impact of our revised reaction rate. For stars of nearly solar composition, we find sizeable variations of some isotopes, whose production is influenced by the activation of close-by branching points that are sensitive to the neutron density, in particular, the two radioactive nuclei ^{60}Fe and ^{205}Pb, as well as ^{152}Gd.

5.
BMC Gastroenterol ; 21(1): 31, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33478385

RESUMO

BACKGROUND: Percutaneous Endoscopic Gastrostomy (PEG) can involve some complications, despite the good safety of its track record. The Buried Bumper Syndrome (BBS) is a rare, late and dangerous complication that consists in the erosion of the internal bumper through the gastric wall. Case presentation We report the development of BBS in a man with chronic obstructive pulmonary disease (COPD) who had a persistent chronic cough which was prevalently but not solely in the morning and required placement of a PEG tube for continuous infusion of Levodopa/carbidopa intestinal gel for advanced Parkinson's disease. CONCLUSION: We believe that COPD with chronic cough while not representing an absolute contraindication to PEG placement, may potentially cause BBS and therefore an appropriate regimen of tube care by expert personnel is mandatory in this setting.


Assuntos
Gastrostomia , Doença Pulmonar Obstrutiva Crônica , Contraindicações , Tosse/etiologia , Nutrição Enteral , Humanos , Masculino , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/terapia
6.
Death Stud ; 43(10): 665-667, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30265829

RESUMO

The hypothesis that obituary notices will be less direct/less emotional in the language used for females than for males was tested. A total of 703 consecutive obituaries were examined in a local newspaper and instances of whether the person died or passed away was noted for males and females. A 2 (gender) × 2 (died, passed away) Chi-Square analysis supported the hypothesis: X2 (1) = 8.87, p < .01. Thus, males are more likely to die, whereas females are more likely to pass away.


Assuntos
Atitude Frente a Morte , Estereotipagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Preconceito , Adulto Jovem
8.
Phys Rev Lett ; 121(17): 172701, 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30411966

RESUMO

The ^{22}Ne(p,γ)^{23}Na reaction, part of the neon-sodium cycle of hydrogen burning, may explain the observed anticorrelation between sodium and oxygen abundances in globular cluster stars. Its rate is controlled by a number of low-energy resonances and a slowly varying nonresonant component. Three new resonances at E_{p}=156.2, 189.5, and 259.7 keV have recently been observed and confirmed. However, significant uncertainty on the reaction rate remains due to the nonresonant process and to two suggested resonances at E_{p}=71 and 105 keV. Here, new ^{22}Ne(p,γ)^{23}Na data with high statistics and low background are reported. Stringent upper limits of 6×10^{-11} and 7×10^{-11} eV (90% confidence level), respectively, are placed on the two suggested resonances. In addition, the off-resonant S factor has been measured at unprecedented low energy, constraining the contributions from a subthreshold resonance and the direct capture process. As a result, at a temperature of 0.1 GK the error bar of the ^{22}Ne(p,γ)^{23}Na rate is now reduced by 3 orders of magnitude.

9.
Nature ; 492(7429): 393-5, 2012 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-23257880

RESUMO

Globular star clusters that formed at the same cosmic time may have evolved rather differently from the dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend progressively to segregate stars more massive than the average towards the cluster centre. Therefore clusters with the same chronological age may have reached quite different stages of their dynamical history (that is, they may have different 'dynamical ages'). Blue straggler stars have masses greater than those at the turn-off point on the main sequence and therefore must be the result of either a collision or a mass-transfer event. Because they are among the most massive and luminous objects in old clusters, they can be used as test particles with which to probe dynamical evolution. Here we report that globular clusters can be grouped into a few distinct families on the basis of the radial distribution of blue stragglers. This grouping corresponds well to an effective ranking of the dynamical stage reached by stellar systems, thereby permitting a direct measure of the cluster dynamical age purely from observed properties.

10.
Int J Immunogenet ; 44(4): 158-163, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28547851

RESUMO

Allelic and genotype frequencies of four cytokine genes were obtained from 738 subjects from North- and South-Italy. Populations were in Hardy-Weinberg equilibrium for all genes but significantly differed in the frequency of all SNPs and three haplotypes. In the MDS graph, they were plotted in separate positions close to Europeans and an Ivorian population, respectively.


Assuntos
Citocinas/genética , Frequência do Gene , Haplótipos , Polimorfismo de Nucleotídeo Único , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade
11.
Curr Psychol ; : 1, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36105741
12.
Curr Psychol ; : 1, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36105742
13.
Phys Rev Lett ; 117(14): 142502, 2016 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-27740778

RESUMO

The ^{17}O(p,α)^{14}N reaction plays a key role in various astrophysical scenarios, from asymptotic giant branch stars to classical novae. It affects the synthesis of rare isotopes such as ^{17}O and ^{18}F, which can provide constraints on astrophysical models. A new direct determination of the E_{R}=64.5 keV resonance strength performed at the Laboratory for Underground Nuclear Astrophysics (LUNA) accelerator has led to the most accurate value to date ωγ=10.0±1.4_{stat}±0.7_{syst} neV, thanks to a significant background reduction underground and generally improved experimental conditions. The (bare) proton partial width of the corresponding state at E_{x}=5672 keV in ^{18}F is Γ_{p}=35±5_{stat}±3_{syst} neV. This width is about a factor of 2 higher than previously estimated, thus leading to a factor of 2 increase in the ^{17}O(p, α)^{14}N reaction rate at astrophysical temperatures relevant to shell hydrogen burning in red giant and asymptotic giant branch stars. The new rate implies lower ^{17}O/^{16}O ratios, with important implications on the interpretation of astrophysical observables from these stars.

14.
Perception ; 45(6): 684-686, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27060182

RESUMO

We asked 100 college students to view a picture ( Figure 1 ) and decide if there were two lamps or one lamp reflected in a mirror. Although the correct answer is two lamps, the vast majority (72%) answered seeing only one lamp. We discuss this illusion.

15.
Am J Psychol ; 129(2): 161-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27424418

RESUMO

We gave 127 undergraduates questionnaires about their iPod and texting dependence and 2 hypothetical delay discounting scenarios related to free downloaded songs and free texting for life. Using regression analyses we found that when iPod dependence was the dependent variable, Text2-excessive use, Text4-psychological and behavioral symptoms, iPod2-excessive use, and iPod3-relationship disruption were significant predictors of discounting. When texting dependence was the dependent variable, Text4-psychological and behavioral symptoms and iPod3-relationship disruption were significant predictors of discounting. These are the first data to show that delay discounting relates to certain aspects of social media, namely iPod and texting dependence. These data also show that across these 2 dependencies, both psychological and behavioral symptoms and relationship disruptions are affected.


Assuntos
Comportamento Aditivo/psicologia , Desvalorização pelo Atraso/fisiologia , MP3-Player , Mídias Sociais , Envio de Mensagens de Texto , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
16.
Curr Sports Med Rep ; 15(1): 23-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26745166

RESUMO

This literature review will summarize, compare, and evaluate the reviewed studies addressing and investigating the relationship between concussion and the sports of hockey. We will accomplish this by identifying prevalence rates, recognizing common mechanisms of causation, describing and discussing prevention and care, and summarizing the results to provide implications for further studies. We conclude by indicating the important mental health issues as well as potentially severe and long-lasting impact concussions can and do have on those that receive them as well as on the friends and families of those who sustain a concussion.


Assuntos
Concussão Encefálica/diagnóstico , Concussão Encefálica/etiologia , Hóquei/lesões , Concussão Encefálica/prevenção & controle , Humanos
17.
Phys Rev Lett ; 115(25): 252501, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26722918

RESUMO

The ^{22}Ne(p,γ)^{23}Na reaction takes part in the neon-sodium cycle of hydrogen burning. This cycle affects the synthesis of the elements between ^{20}Ne and ^{27}Al in asymptotic giant branch stars and novae. The ^{22}Ne(p,γ)^{23}Na reaction rate is very uncertain because of a large number of unobserved resonances lying in the Gamow window. At proton energies below 400 keV, only upper limits exist in the literature for the resonance strengths. Previous reaction rate evaluations differ by large factors. In the present work, the first direct observations of the ^{22}Ne(p,γ)^{23}Na resonances at 156.2, 189.5, and 259.7 keV are reported. Their resonance strengths are derived with 2%-7% uncertainty. In addition, upper limits for three other resonances are greatly reduced. Data are taken using a windowless ^{22}Ne gas target and high-purity germanium detectors at the Laboratory for Underground Nuclear Astrophysics in the Gran Sasso laboratory of the National Institute for Nuclear Physics, Italy, taking advantage of the ultralow background observed deep underground. The new reaction rate is a factor of 20 higher than the recent evaluation at a temperature of 0.1 GK, relevant to nucleosynthesis in asymptotic giant branch stars.

18.
Nature ; 462(7276): 1028-31, 2009 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-20033041

RESUMO

Stars in globular clusters are generally believed to have all formed at the same time, early in the Galaxy's history. 'Blue stragglers' are stars massive enough that they should have evolved into white dwarfs long ago. Two possible mechanisms have been proposed for their formation: mass transfer between binary companions and stellar mergers resulting from direct collisions between two stars. Recently the binary explanation was claimed to be dominant. Here we report that there are two distinct parallel sequences of blue stragglers in M 30. This globular cluster is thought to have undergone 'core collapse', during which both the collision rate and the mass transfer activity in binary systems would have been enhanced. We suggest that the two observed sequences are a consequence of cluster core collapse, with the bluer population arising from direct stellar collisions and the redder one arising from the evolution of close binaries that are probably still experiencing an active phase of mass transfer.

19.
Nature ; 462(7272): 483-6, 2009 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-19940920

RESUMO

Globular star clusters are compact and massive stellar systems old enough to have witnessed the entire history of our Galaxy, the Milky Way. Although recent results suggest that their formation may have been more complex than previously thought, they still are the best approximation to a stellar population formed over a relatively short timescale (less than 1 Gyr) and with virtually no dispersion in the iron content. Indeed, only one cluster-like system (omega Centauri) in the Galactic halo is known to have multiple stellar populations with a significant spread in iron abundance and age. Similar findings in the Galactic bulge have been hampered by the obscuration arising from thick and varying layers of interstellar dust. Here we report that Terzan 5, a globular-cluster-like system in the Galactic bulge, has two stellar populations with different iron contents and ages. Terzan 5 could be the surviving remnant of one of the primordial building blocks that are thought to merge and form galaxy bulges.

20.
Int J Pharm X ; 7: 100233, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38379554

RESUMO

Polysaccharides were identified, which allow for colon targeting in human Inflammatory Bowel Disease (IBD) patients, as well as in rats and dogs (which are frequently used as animals in preclinical studies). The polysaccharides are degraded by colonic enzymes (secreted by bacteria), triggering the onset of drug release at the target site. It has to be pointed out that the microbiota in rats, dogs and humans substantially differ. Thus, the performance of this type of colon targeting system observed in animals might not be predictive for patients. The aim of this study was to limit this risk. Different polysaccharides were exposed to culture medium inoculated with fecal samples from IBD patients, healthy dogs and "IBD rats" (in which colonic inflammation was induced). Dynamic changes in the pH of the culture medium were used as an indicator for the proliferation of the bacteria and, thus, the potential of the polysaccharides to serve as their substrate. Fundamental differences were observed with respect to the extent of the pH variations as well as their species-dependency. The most promising polysaccharides were used to prepare polymeric film coatings surrounding 5-aminosaliciylic acid (5-ASA)-loaded starter cores. To limit premature polysaccharide dissolution/swelling in the upper gastro intestinal tract, ethylcellulose was also included in the film coatings. Drug release was monitored upon exposure to culture medium inoculated with fecal samples from IBD patients, healthy dogs and "IBD rats". For reasons of comparison, also 5-ASA release in pure culture medium was measured. Most film coatings showed highly species-dependent drug release kinetics or limited colon targeting capacity. Interestingly, extracts from aloe vera and reishi (a mushroom) showed a promising potential for colon targeting in all species.

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