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Ac stark shifts induced by a YAG laser in the nP and nF Rydberg series in xenon

Nonresonant ac Stark shifts of Rydberg states in Xe have been investigated by probing an atomic transition with a weak UV light in the presence of an intense YAG-laser pulse. Rydberg atoms produced through two-photon excitation, 5p → np (n = 15-48) and 5p → nf (n = 12-49), are subsequently ionized. IR-laser-induced shifts of the resonant ionization profiles are then measured. The measured shift, 3

Spectroscopy of the np and nf even-parity rydberg series in xenon by two-photon excitation

The energies of the np[1/2]o, np[3/2]2, np[5/212, nf[3/2] 2, and nf[5/2]2 Rydberg states in Xe are measured within +0.3/-0.5 cm-1 from n = 12 to n = 49. The Rydberg states are excited by nonresonant two-photon absorption and detected by dc field ionization or infrared photoionization. We determine the ionization limit and the quantum defects for the different series involved.

Genetic sharing with cardiovascular disease risk factors and diabetes reveals novel bone mineral density loci

Bone Mineral Density (BMD) is a highly heritable trait, but genome-wide association studies have identified few genetic risk factors. Epidemiological studies suggest associations between BMD and several traits and diseases, but the nature of the suggestive comorbidity is still unknown. We used a novel genetic pleiotropy-informed conditional False Discovery Rate (FDR) method to identify single nucl

Idrottande barn och ung­domar »vaccineras« mot frakturer i vuxenlivet : Träning är bra för alla – på olika sätt

High mechanical load in alternating directions with sufficient rest in between the loading periods is one of the best stimuli to enhance bone mass and skeletal structure, both contributing independently to bone strength. The age-frame where skeletal benefits from exercise are largest is in late pre- and early peri-puberty. Recent publications with low level of evidence infer that such skeletal ben

Abnormally decreased regional bone density in athletes with medial tibial stress syndrome

Medial tibial stress syndrome, a common condition of uncertain origin found in athletes, is characterized by pain in the distal posteromedial aspect of the tibia during exercise, with or without increased scintigraphic uptake in the affected region. To determine whether medial tibial stress syndrome with increased scintigraphic uptake is associated with a change in tibial bone mineral density conf

The duration of exercise as a regulator of bone mass

Exercise is associated with increased peak bone mineral density (BMD). To determine the relationship between the duration of exercise and BMD, we measured BMD of the axial and appendicular skeleton by dual-energy X-ray absorptiometry (DXA), and speed of sound (SOS), broadband attenuation (BUA), and stiffness index by quantitative ultrasound (QUS) of the calcaneus, in 67 active male national soccer

Bone loss in relation to menopause : A prospective study during 16 years

This prospective study evaluated bone loss in the peri- and postmenopausal period in 156 women followed from age 48 to 64 years. All women were premenopausal at the start of the study. Areal bone mineral density (g/cm2) was measured by single-photon absorptiometry (SPA) of the forearm at the 1 cm level (BMD 1 cm) and the 6 cm level (BMD 6 cm) every second year. Onset of menopause (MP) was determin

The evidence that exercise during growth or adulthood reduces the risk of fragility fractures is weak

There has never been, and will never be, a randomized double-blind placebo-controlled trial demonstrating that exercise in youth, adulthood or old age reduces fragility or osteoporosis-related fractures in old age. The next level of evidence, a randomized, controlled but unblinded study with fractures as an end-point is feasible but has never been done. The basis for the belief that exercise reduc

Skeletal effects of exercise in men

No prospective randomized study with fracture as end point exists in men. Data from retrospective and prospective observational and case control studies suggest that activity in men is associated with reduced fracture risk. This may be correct, but consistently replicated sampling bias may produce the same observation, as these studies are hypothesis generating, never hypothesis testing. Higher mu

Heterogeneity in the growth of the axial and appendicular skeleton in boys : Implications for the pathogenesis of bone fragility in men

Men with spine fractures have reduced vertebral body (VB) volume and volumetric bone mineral density (vBMD). Men with hip fractures have reduced femoral neck (FN) volume and vBMD, site-specific deficits that may have their origins in growth. To describe the tempo of growth in regional bone size, bone mineral content (BMC), and vBMD, we measured bone length, periosteal and endocortical diameters, B

On exposure to anorexia nervosa, the temporal variation in axial and appendicular skeletal development predisposes to site-specific deficits in bone size and density : A cross-sectional study

Skeletal development is heterogeneous. Throughout growth, bone size is more maturationally advanced than the mineral being accrued within its periosteal envelope; before puberty, appendicular growth is more rapid than axial growth; during puberty, appendicular growth slows and axial growth accelerates. We studied women with differing age of onset of anorexia nervosa to determine whether this tempo

Bone size and volumetric density in women with anorexia nervosa receiving estrogen replacement therapy and in women recovered from anorexia nervosa

Anorexia nervosa is associated with bone loss during adulthood, but may also delay skeletal growth and mineral accrual during growth. We asked the following questions. 1) Is anorexia nervosa associated with reduced bone size and reduced volumetric bone mineral density (vBMD)? 2) Is estrogen replacement therapy (ERT) or recovery from anorexia nervosa associated with normal bone size and vBMD? Using

Bone mass and density of the head

Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry in the upper half of the skull, in 324 residents (178 women and 146 men, age-range 20-87 years) in the city of Malmo, Sweden. Since muscular activity influences the skeleton we found it was of interest to compare one region influenced by physical load with one virtually unaffected by physical stress. The skull may be assum

Very long-term survival and late sudden cardiac death in cardiac resynchronization therapy patients

AIMS: The very long-term outcome of patients who survive the first few years after receiving cardiac resynchronization therapy (CRT) has not been well described thus far. We aimed to provide long-term outcomes, especially with regard to the occurrence of sudden cardiac death (SCD), in CRT patients without (CRT-P) and with defibrillator (CRT-D).METHODS AND RESULTS: A total of 1775 patients, with is