X-ray fluorescence analysis of metal distributions in cryogenic biological samples using large-acceptance-angle SDD detection and continuous scanning at the Hard X-ray Micro/Nano-Probe beamline P06 at PETRA III.

A new Rococo 2 X-ray fluorescence detector was implemented into the cryogenic sample environment at the Hard X-ray Micro/Nano-Probe beamline P06 at PETRA III, DESY, Hamburg, Germany. A four sensor-field cloverleaf design is optimized for the investigation of planar samples and operates in a backscattering geometry resulting in a large solid angle of up to 1.1 steradian. The detector, coupled with the Xspress 3 pulse processor, enables measurements at high count rates of up to 106 counts per second per sensor. The measured energy resolution of ∼129 eV (Mn Kα at 10000 counts s-1) is only minimally impaired at the highest count rates. The resulting high detection sensitivity allows for an accurate determination of trace element distributions such as in thin frozen hydrated biological specimens. First proof-of-principle measurements using continuous-movement 2D scans of frozen hydrated HeLa cells as a model system are reported to demonstrate the potential of the new detection system.

Adolescent egocentrism and cognitive functioning during late adolescence.

The relationship between adolescent egocentrism and post-formal thinking was examined in 163 college undergraduates. Participants were administered the Imaginary Audience Scale and the Social Paradigm Belief Inventory. Results showed that females had higher levels of adolescent egocentrism than did males. A weak negative correlation between egocentrism and cognitive reasoning was found for females during late adolescence. The findings are consistent with Peterson and Roscoe's (1991) study of egocentrism in older adolescent females.

Effects of developmental care on behavioral organization in very-low-birth-weight infants.

The purpose of this study was to determine whether modifying care to reduce stressors in the neonatal intensive care unit and support infant development affected physiological, motor, and behavioral state organization. Twenty-one infants weighing less than 1501 g were studied prior to a nursing staff-training program (control) and 24 infants were studied posttraining (study). Nurses were taught to lower environmental stress, reduce procedural stress, and facilitate motor and sleep-wake organization. Oxygen saturation, motor activity, posture, and sleep-wake states were measured biweekly during routine care. Study infants showed higher oxygen saturation levels, fewer disorganized and jerky movements, more flexor movements, more flexed posture, and more alert-wakefulness than controls. Results suggest that this approach to care may have potential to improve behavioral organization during the preterm period.

Outcomes of developmentally supportive nursing care for very low birth weight infants.

Numerous aspects of the intensive care environment are stressful for low birth weight infants and may play a role in adverse developmental and behavioral outcome. The purpose of this study was to determine whether staff education in care protocols designed to make the environment less stressful and thereby support the infant's development would improve short-term outcomes. Twenty-one infants (less than 1,501 gms) were studied during the preeducation period and 24 infants were studied following staff education. The educational program successfully altered nursing care. Experimental infants had more optimal respiratory and feeding status, lower levels of morbidity, shorter hospitalization, and improved behavioral organization.