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Generation and spatiotemporal characterization of ultrashort vortex pulses

Some light beams rotate as they propagate. If it is not the polarization vector, but the phase structure that rotates, the beam is said to carry orbital angular momentum (OAM). Such beams exhibit a helical phase front, where the phase rotates around a symmetry center. Because the phase in the center is undefined (and the intensity there is therefore zero), it is often termed a phase singularity or

Noncollinear optical gating - A method for intra-cavity single attosecond pulse generation?

The process of high-order harmonic generation requires laser intensities around 1014 W/cm2, most easily reached with laser pulses of high energy, thus implicitly limiting the repetition rate of attosecond sources. A route towards multi-MHz attosecond sources relies on HHG inside a passive enhancement cavity [1]. Although successfully demonstrated for attosecond pulse trains, the generation of sing

Attosecond insight into electron correlation

Photoionization with a single photon is one of the fundamental processes in nature, in which one electron is ripped away from its atom. Traditionally studied in the energy domain, this process was believed to be instantaneous, but recent advances in the production of attosecond pulses (1 as 10−18 s) in the eXtreme UltraViolet (XUV) have renewed interest in understanding the temporal aspects of ele

MiR-378a suppresses tenogenic differentiation and tendon repair by targeting at TGF-β2

Background: Tendons are a crucial component of the musculoskeletal system and responsible for transmission forces derived from muscle to bone. Patients with tendon injuries are often observed with decreased collagen production and matrix degeneration, and healing of tendon injuries remains a challenge as a result of limited understanding of tendon biology. Recent studies highlight the contribution

Prevalence of heart failure and other risk factors among first-degree relatives of women with peripartum cardiomyopathy

Objectives: Peripartum cardiomyopathy (PPCM) is a rare disease carrying a risk of death and chronic heart failure.It is unknown if women with PPCM have a family history of heart failure. We investigated the prevalence of heart failure and hypertension in first-degree relatives to women with PPCM. Methods: A cohort of 61 women with PPCM was identified through the nationwide Danish registers from 20

The trajectory of functional decline over the last 4 months of life in a palliative care population : A prospective, consecutive cohort study

Background: Understanding current patterns of functional decline will inform patient care and has health service and resource implications. Aim: This prospective consecutive cohort study aims to map the shape of functional decline trajectories at the end of life by diagnosis. Design: Changes in functional status were measured using the Australia-modified Karnofsky Performance Status Scale. Segment

Effects of a vortex generator pair on jet impingement heat transfer in cross-flow

Jet impingement cooling is commonly used in gas turbines. Usually the spent air from the upstream jets forms a cross-flow past the downstream jets, which degrades their heat transfer performance. In the present study, a new method was proposed to promote the jet penetration and enhance the impingement heat transfer. By placing a delta-winglet vortex generator pair (VGP) in the cross-flow upstream

Tin-oxide nanoparticles deposited from a beam : what happens to the composition?

The debate around the oxidation states occurring in laboratory-prepared tin-oxide samples has been for a long time an obstacle for an unambiguous assignment of characterization studies performed on such samples. In particular the changes in the Sn core-level energies caused by oxidation - i.e. the chemical shifts - as measured by photoelectron spectroscopy (PES) have been under discussion. The ass

Spatiotemporal coupling of attosecond pulses

The shortest light pulses produced to date are of the order of a few tens of attoseconds, with central frequencies in the extreme UV range and bandwidths exceeding tens of electronvolts. They are often produced as a train of pulses separated by half the driving laser period, leading in the frequency domain to a spectrum of high, odd-order harmonics. As light pulses become shorter and more spectral

Intake of individual fatty acids and risk of prostate cancer in the European prospective investigation into cancer and nutrition

The associations of individual dietary fatty acids with prostate cancer risk have not been examined comprehensively. We examined the prospective association of individual dietary fatty acids with prostate cancer risk overall, by tumor subtypes, and prostate cancer death. 142,239 men from the European Prospective Investigation into Cancer and Nutrition who were free from cancer at recruitment were

Reduced Long-Term Risk of Aortic Aneurysm and Aortic Dissection Among Individuals With Type 2 Diabetes Mellitus : A Nationwide Observational Study

BACKGROUND: No studies have examined long-term risks for aortic aneurysm (AA) and aortic dissection (AD) or mortality after AA or AD hospitalization among patients with type 2 diabetes mellitus (T2DM).METHODS AND RESULTS: In this observational cohort study, we linked data for patients with T2DM in the Swedish National Diabetes Register, and 5 individually matched population-based control subjects

Light and oxygen induce chain scission of conjugated polymers in solution

Conjugated polymers have been widely studied as flexible, versatile semiconductors in organic electronics. However, the material stability is one of the problems limiting their applications. Thus, understanding the degradation process of conjugated polymers is crucial. In this work, we monitored the chain scission of the model polymer MEH-PPV in chloroform solutions under different conditions by a

Disentangling population strategies of two cladocerans adapted to different ultraviolet regimes

Zooplankton have evolved several mechanisms to deal with environmental threats, such as ultraviolet radiation (UVR), and in order to identify strategies inherent to organisms exposed to different UVR environments, we here examine life-history traits of two lineages of Daphnia pulex. The lineages differed in the UVR dose they had received at their place of origin from extremely high UVR stress at h

One evidence base; three stories : do opioids relieve chronic breathlessness?

The efficacy of low-dose systemic opioids for chronic breathlessness was questioned by the recent Cochrane review by Barnes et al We examined the reasons for this conflicting finding and re-evaluated the efficacy of systemic opioids. Compared with previous meta-analyses, Barnes et al reported a smaller effect and lower precision, but did not account for matched data of crossover trials (11/12 incl

Emissions into the air from bitumen and rubber bitumen - Implications for asphalt workers' exposure

The risk among asphalt workers of developing adverse health effects may increase due to their occupational exposure. One area of special concern arises when rubber granules are mixed into bitumen to enhance asphalt properties. This research characterizes and compares bitumen and rubber bitumen regarding the emissions of and workers' exposure to particulates, polycyclic aromatic hydrocarbons (PAHs)