Abstract
A nanohertz-frequency stochastic gravitational-wave background can potentially be detected through the precise timing of an array of millisecond pulsars. This background produces ...low-frequency noise in the pulse arrival times that would have a characteristic spectrum common to all pulsars and a well-defined spatial correlation. Recently the North American Nanohertz Observatory for Gravitational Waves collaboration (NANOGrav) found evidence for the common-spectrum component in their 12.5 yr data set. Here we report on a search for the background using the second data release of the Parkes Pulsar Timing Array. If we are forced to choose between the two NANOGrav models—one with a common-spectrum process and one without—we find strong support for the common-spectrum process. However, in this paper, we consider the possibility that the analysis suffers from model misspecification. In particular, we present simulated data sets that contain noise with distinctive spectra but show strong evidence for a common-spectrum process under the standard assumptions. The Parkes data show no significant evidence for, or against, the spatially correlated Hellings–Downs signature of the gravitational-wave background. Assuming we did observe the process underlying the spatially uncorrelated component of the background, we infer its amplitude to be
A
=
2.2
−
0.3
+
0.4
×
10
−
15
in units of gravitational-wave strain at a frequency of 1 yr
−1
. Extensions and combinations of existing and new data sets will improve the prospects of identifying spatial correlations that are necessary to claim a detection of the gravitational-wave background.
Cell-mediated adaptive immunity is critical for host defense, but little is known about T cell behavior during delivery of effector function. Here we investigate relationships among antigen ...presentation, T cell motility, and local production of effector cytokines by CD4
+ T cells within hepatic granulomas triggered by Bacille Calmette-Guérin or
Mycobacterium tuberculosis. At steady-state, only small fractions of mycobacteria-specific T cells showed antigen-induced migration arrest within granulomas, resulting in low-level, polarized secretion of cytokines. However, exogenous antigen elicited rapid arrest and robust cytokine production by the vast majority of effector T cells. These findings suggest that limited antigen presentation and/or recognition within granulomas evoke a muted T cell response drawing on only a fraction of the host's potential effector capacity. Our results provide new insights into the regulation of host-protective functions, especially how antigen availability influences T cell dynamics and, in turn, effector T cell function during chronic infection.
► Effector T cells within mycobacterial granulomas show limited antigen activation ► Effector T cells within granulomas have submaximal responses ► Low frequency of arrested effector T cells display polarized cytokine secretion ► Effector T cell motility and cytokine production have an inverse relationship
Although the main Raman features of semiconducting transition metal dichalcogenides are well known for the monolayer and bulk, there are important differences exhibited by few layered systems which ...have not been fully addressed. WSe2 samples were synthesized and ab-initio calculations carried out. We calculated phonon dispersions and Raman-active modes in layered systems: WSe2, MoSe2, WS2 and MoS2 ranging from monolayers to five-layers and the bulk. First, we confirmed that as the number of layers increase, the E', E″ and E2g modes shift to lower frequencies, and the A'1 and A1g modes shift to higher frequencies. Second, new high frequency first order A'1 and A1g modes appear, explaining recently reported experimental data for WSe2, MoSe2 and MoS2. Third, splitting of modes around A'1 and A1g is found which explains those observed in MoSe2. Finally, exterior and interior layers possess different vibrational frequencies. Therefore, it is now possible to precisely identify few-layered STMD.
The continuation of the COVID-19 epidemic poses novel challenges for adult ostomy patients care. It is essential to explore nursing management for ostomy patients to ensure patients receive ...standardized care while minimizing exposure to COVID-19. This article reviews the perioperative nursing of Chinese adult ostomy patients in the post-epidemic era, as well as outpatient review after discharge and home care, to provide reference and basis for medical staff and patients in the post-pandemic era.
Aims/hypothesis
Increased inflammation and oxidative stress are associated with insulin resistance (IR) and metabolic disorders. Serum histidine levels are lower and are negatively associated with ...inflammation and oxidative stress in obese women. The objective of this study was to evaluate the efficacy of histidine supplementation on IR, inflammation, oxidative stress and metabolic disorders in obese women with the metabolic syndrome (MetS).
Methods
A total of 100 obese women aged 33–51 years with BMI ≥ 28 kg/m
2
and diagnosed with MetS were included following a health examination in the community hospital in this randomised, double-blinded, placebo-controlled trial. Participants were allocated to interventions by an investigator using sequentially numbered sealed envelopes and received 4 g/day histidine (
n
= 50) or identical placebo (
n
= 50) for 12 weeks. Participants then attended the same clinic every 2 weeks for scheduled interviews and to count tablets returned. Serum histidine, HOMA-IR, BMI, waist circumference, fat mass, serum NEFA, and variables connected to inflammation and oxidative stress were measured at baseline and 12 weeks. Participants, examining physicians and investigators assessing the outcomes were blinded to group assignment. In addition, the inflammatory mechanisms of histidine were also explored in adipocytes.
Results
At 12 weeks, a total of 92 participants completed this trail. Compared with the placebo group (
n
= 47), histidine supplementation significantly decreased HOMA-IR (−1.09 95% CI −1.49, −0.68), BMI (−0.86 kg/m
2
95% CI −1.55, −0.17), waist circumference (−2.86 cm 95% CI −3.86, −1.86), fat mass (−2.71 kg 95% CI −3.69, −1.73), serum NEFA (−173.26 μmol/l 95% CI −208.57, −137.94), serum inflammatory cytokines (TNF-α, −3.96 pg/ml 95% CI −5.29, −2.62; IL-6, −2.15 pg/ml 95% CI −2.52, −1.78), oxidative stress (superoxide dismutase, 17.84 U/ml 95% CI 15.03, 20.65; glutathione peroxidase, 13.71 nmol/ml 95% CI 9.65, 17.78) and increased serum histidine and adiponectin by 18.23 μmol/l 95% CI 11.74, 24.71 and 2.02 ng/ml 95% CI 0.60, 3.44 in histidine supplementation group (
n
= 45), respectively. There were significant correlations between changes in serum histidine and changes of IR and its risk factors. No side effects were observed during the intervention. In vitro study indicated that histidine suppresses
IL6
and
TNF
mRNA expression and nuclear factor kappa-B (NF-κB) protein production in palmitic acid-induced adipocytes in a dose-dependent manner, and these changes were diminished by an inhibitor of NF-κB.
Conclusions/interpretation
Histidine supplementation could improve IR, reduce BMI, fat mass and NEFA and suppress inflammation and oxidative stress in obese women with MetS; histidine could improve IR through suppressed pro-inflammatory cytokine expression, possibly by the NF-κB pathway, in adipocytes.
Trial registration
www.chictr.org/cn/ChiCTR-TRC-11001551
Funding
The study was supported by the National Natural Science Fund of China (No. 81202184, 81130049, 81102112), Heilongjiang Post/doctoral Fund (No. LBN-Z12193) and Key Laboratory of Nutrition and Food Hygiene (Harbin Medical University, Heilongjiang Higher Education Institutions, No. YYKFKT1202).
Background Few trials have examined long-term outcomes of advance care planning (ACP) interventions. We examined the efficacy of an ACP intervention on preparation for end-of-life decision making for ...dialysis patients and surrogates and for surrogates’ bereavement outcomes. Study Design A randomized trial compared an ACP intervention (Sharing Patient’s Illness Representations to Increase Trust SPIRIT) to usual care alone, with blinded outcome assessments. Setting & Participants 420 participants (210 dyads of prevalent dialysis patients and their surrogates) from 20 dialysis centers. Intervention Every dyad received usual care. Those randomly assigned to SPIRIT had an in-depth ACP discussion at the center and a follow-up session at home 2 weeks later. Outcomes & Measurements Primary outcomes: preparation for end-of-life decision making, assessed for 12 months, included dyad congruence on goals of care at end of life, patient decisional conflict, surrogate decision-making confidence, and a composite of congruence and surrogate decision-making confidence. Secondary outcomes: bereavement outcomes, assessed for 6 months, included anxiety, depression, and posttraumatic distress symptoms completed by surrogates after patient death. Results Primary outcomes: adjusting for time and baseline values, dyad congruence (OR, 1.89; 95% CI, 1.1-3.3), surrogate decision-making confidence (β = 0.13; 95% CI, 0.01-0.24), and the composite (OR, 1.82; 95% CI, 1.0-3.2) were better in SPIRIT than controls, but patient decisional conflict did not differ between groups (β = −0.01; 95% CI, −0.12 to 0.10). Secondary outcomes: 45 patients died during the study. Surrogates in SPIRIT had less anxiety (β = −1.13; 95% CI, −2.23 to −0.03), depression (β = −2.54; 95% CI, −4.34 to −0.74), and posttraumatic distress (β = −5.75; 95% CI, −10.9 to −0.64) than controls. Limitations Study was conducted in a single US region. Conclusions SPIRIT was associated with improvements in dyad preparation for end-of-life decision making and surrogate bereavement outcomes.
Here, we present a temperature (T) dependent comparison between field-effect and Hall mobilities in field-effect transistors based on few-layered WSe2 exfoliated onto SiO2. Without dielectric ...engineering and beyond a T-dependent threshold gate-voltage, we observe maximum hole mobilities approaching 350 cm(2)/Vs at T = 300 K. The hole Hall mobility reaches a maximum value of 650 cm(2)/Vs as T is lowered below ~150 K, indicating that insofar WSe2-based field-effect transistors (FETs) display the largest Hall mobilities among the transition metal dichalcogenides. The gate capacitance, as extracted from the Hall-effect, reveals the presence of spurious charges in the channel, while the two-terminal sheet resistivity displays two-dimensional variable-range hopping behavior, indicating carrier localization induced by disorder at the interface between WSe2 and SiO2. We argue that improvements in the fabrication protocols as, for example, the use of a substrate free of dangling bonds are likely to produce WSe2-based FETs displaying higher room temperature mobilities, i.e. approaching those of p-doped Si, which would make it a suitable candidate for high performance opto-electronics.
Abstract
Black widows are millisecond pulsars ablating their companions. The material blown from the companion blocks the radio emission, resulting in radio eclipses. The properties of the eclipse ...medium are poorly understood. Here, we present direct evidence of the existence of magnetic fields in the eclipse medium of the black widow PSR J2051−0827 using observations made with the Five-hundred-meter Aperture Spherical radio Telescope. We detect a regular decrease in rotation measure (RM) in the egress of the eclipse, changing from 60 to −28.7 rad m
−2
. The RM gradually changes back to normal when the line of sight moves away from the eclipse. The estimated line-of-sight magnetic field strength in the eclipse medium is ∼0.1 G. The RM reversal could be caused by a change in the magnetic field strength along the line of sight due to binary orbital motion. The RM reversal phenomenon has also been observed in some repeating fast radio bursts (FRBs), and the study of spider pulsars may provide additional information about the origin of FRBs.
The mechanism for N2O formation over CHA and Cu-CHA zeolite catalysts during NH3-SCR is investigated using density functional theory calculations. Direct NH4NO3 decomposition, which is commonly ...regarded as the main source of N2O, is found to be associated with high barriers in the absence of Brønsted acid sites. Although Brønsted acid sites promote NH4NO3 decomposition, it is still a highly activated process. Low-temperature N2O formation is instead found to be connected with an NO + NH3 reaction over Cu-sites. In particular, N2O can be formed from H2NNO with a low barrier over Cu-OOH-Cu complexes, which are proposed intermediates in the catalytic cycle for NH3-SCR over Cu-CHA. This finding provides an explanation for the experimentally observed low-temperature N2O formation and the relation between Cu loading and N2O formation. The proposed mechanisms open up strategies to enhance the selectivity to N2 during NH3-SCR.
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