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Attosecond excitation of electron wavepackets

We present experiments, supported by time-dependent Schrödinger simulations, on the dynamics of Helium bound states after an attosecond excitation in the presence of a strong infrared laser field.

Many-electron dynamics of heavy atoms in intense laser fields : Effects of screening and correlation

We discuss the role of many-electron interactions in multiphoton multielectron ionization of heavy atoms and try to indicate the relative importance of collective effects and screening, relaxation and shakeup, and Fermi sea correlations. The purpose of the work is to look for approximations in which the photoemission processes have been renormalized in consistent ways with respect to the field and

Spatial profiles of high-order harmonics generated by a femtosecond cr:Lisaf laser

We report the angular distributions of high-order harmonic radiation generated in neon and in argon using a 140 fs Cr:LisAF laser system. The profiles show an evolution from Gaussian to near flat-top. No substructure is observed except at the highest intensity in a completely ionized gas. The divergence of the harmonics is found to depend essentially on whether they belong to the plateau or to the

Propagation effects in high-order harmonic generation in rare gases

We study the role of propagation effects in high-order harmonic-generation experiments. The phase-matching integrals are calculated in the weak-field limit by taking into account the dispersion of the rare-gas medium at each harmonic frequency and the absorption of the harmonics. The refractive indices of the rare gases are deduced from a calculation of the dynamic polarizabilities within the fram

Theoretical aspects of intense field harmonic generation

We present theoretical studies of high-order harmonic generation in a rare-gas medium. The experimental results obtained at Saclay with a 1064 nm Nd-YAG laser in the 1013 W cm-2 intensity range are summarized. The harmonic emission strengths first decrease rather steeply for the first orders, then form a long plateau up to the 21st harmonic in xenon, or up to the 33rd harmonic in argon, before dec

Laser-intensity effects in the energy distributions of electrons produced in multiphoton ionization of rare gases

The energy spectra of electrons produced in multiphoton ionization of rare gases display a large number of peaks corresponding to the absorption of much more than a minimum number of photons required to ionize the atom. A retarding-potential method has been used to analyze the energy of electrons produced in the multiphoton ionization of He, Ne, and Xe at 1064 and 532 nm in a broad range of laser

Optimizing high-order harmonic generation in strong fields

We present high-order harmonic generation results obtained with different laser systems a 1 ps 1053 nm Nd-glass laser a 2 ps 616 nm synchronously pumped dye laser a 36 ps 1064 nm mode-locked Nd-YAG laser and the second harmonics (308 nm and 532 nm) of the latter two systems. We investigate the influence of the laser pulse width the excitation wavelength (from the near infrared to the ultraviolet)

Theoretical aspects of three-photon two-color ionization of xenon through ac-stark-shifted resonant rydberg states

We present a theoretical analysis of a recent experiment [J. Opt. Soc. Am. B 6, 1513 (1989)] on two-color threephotonionization of Xe through resonant even-parity Rydberg states. We calculate second-order ac-Stark shifts, two-photon Rabi frequencies, and ionization widths by using wave functions obtained from a multichannel quantum-defect-theory analysis of the Rydberg series in Xe. We perform a d

Uptake, depuration and sublethal effects of the neonicotinoid, imidacloprid, exposure in Sydney rock oysters

The broad utilisation of imidacloprid (IMI)in agriculture poses an increasing risk to aquatic organisms. However, the potential impacts on commercially important shellfish and chemical residues after exposure, are yet to be assessed. We investigated the levels of IMI in Sydney rock oyster (SRO)tissue during a three-day uptake and four-day depuration cycle using liquid chromatography-mass spectrome

The significance of bicuspid aortic valve after surgery for acute type A aortic dissection

OBJECTIVE: Decision-making concerning the extent of the repair of acute type A aortic dissection (ATAAD) includes functional and anatomical assessment of the aortic valve. We hypothesized that bicuspid aortic valve (BAV) does not impact outcome after surgery for ATAAD. We therefore evaluated the outcome after ATAAD surgery in relation to the presence of BAV, acute aortic regurgitation (AR), and su

Is there a weekend effect in surgery for type A dissection? - Results from the NORCAAD database

BACKGROUND: Aortic dissection type A requires immediate surgery. In general surgery populations, patients operated during weekends have higher mortality rates compared to patients operated on weekdays. The weekend effect in aortic dissection type A has not been studied in detail.METHODS: The Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) registry includes patients (N=1,159) who und

Long-term outcome after coronary endarterectomy adjunct to coronary artery bypass grafting

OBJECTIVES: Coronary endarterectomy (CE) in coronary artery bypass grafting (CABG) is occasionally required to achieve revascularization in diffusely diseased vessels. Its beneficial effect has been questioned because of an increased risk of perioperative mortality and morbidity; however, its influence on the long-term outcome remains uncertain. The purpose of the study was to evaluate the impact

Preoperative dual antiplatelet therapy increases bleeding and transfusions but not mortality in acute aortic dissection type A repair

OBJECTIVES: Acute aortic dissection type A is a life-threatening condition, warranting immediate surgery. Presentation with sudden chest pain confers a risk of misdiagnosis as acute coronary syndrome resulting in subsequent potent antiplatelet treatment. We investigated the impact of dual antiplatelet therapy (DAPT) on bleeding and mortality using the Nordic Consortium for Acute Type A Aortic Diss

Difference in Outcome Following Surgery for Native Aortic and Mitral Valve Infective Endocarditis

BACKGROUND: We investigated differences in clinical presentation, microbiology, and short- and long-term results according to the affected valve in patients who underwent surgery for left-sided native valve infective endocarditis (IE).METHODS: This was a single-center retrospective study of 117 patients with isolated mitral valve IE (group M) and 140 patients with isolated aortic valve IE (group A

Hospital volumes and later year of operation correlates with better outcomes in acute Type A aortic dissection

OBJECTIVES: Acute Type A aortic dissection remains a life-threatening disease, but there are indications that its surgical mortality is decreasing. The aim of this report was to study how surgical mortality has changed and what influences those changes.METHODS: Nordic Consortium for Acute Type A Aortic Dissection is a retrospective database comprising 1159 patients (mean age 61.6 ± 12.2 years, 68%

Bone mineral loss after lower extremity trauma. 62 cases followed for 15-38 years

62 former patients, who had been treated at our department for tibial shaft fracture (n 38) or knee ligament injury (n 24) 15-38 years earlier, were re-evaluated for post-traumatic osteopenia. 62 age- and sex-matched subjects without fracture served as controls. By means of a Lunar DEXA apparatus we measured the bone mineral density (BMD) in the total body, the hips and special regions of interest

Correlation between estradiol-17 beta and progesterone cytosol receptor concentration, histologic differentiation and 3H-thymidine incorporation in endometrial carcinoma

Women treated with estrogen exhibit a higher risk of developing endometrial cancer. steroid hormones exert their effects on target tissue through specific cytosol receptor protein. Knowledge of this steroid receptor concentration in endometrial carcinoma might facilitate the treatment of recurrences. We have compared the concentrations of endometrial estrogen and progesterone cytosol receptors wit