Antiferromagnetic Ordering and Transport Anomalies in Single-Crystalline CeAgAs₂

Single crystals of the ternary cerium arsenide CeAgAs(2)were grown by chemical vapor transport. They were studied by means of x-ray diffraction, magnetization, heat capacity and electrical transport measurements. The experimental research was supplemented with electronic band structure calculations. The compound was confirmed to order antiferromagnetically at the Neel temperature of 4.9 K and to undergo metamagnetic transition in a field of 0.5 T at 1.72 K. The electrical resistivity shows distinct increase at low temperatures, which origin is discussed in terms of pseudo-gap formation in the density of states at the Fermi level and quantum corrections to the resistivity in the presence of atom disorder due to crystal structure imperfections

Use of Arterial Catheters in the Management of Acute Aortic Dissection

PURPOSE: The aim of this study was to investigate the relationship between the use of invasive arterial blood pressure (IBP) monitoring and reaching established aggressive medical management goals in acute aortic dissection. METHODS: Data were collected through a retrospective chart review of patients diagnosed with acute aortic syndromes of the thoracic cavity who required transport to tertiary care over a 28-month period. The 2010 American Heart Association medical management goals of thoracic aortic disease were used as hemodynamic end points. RESULTS: A total of 208 patients were included, with 113 (54%) diagnosed at least in part with acute Stanford Type A aortic dissections and the remaining 95 (46%) having isolated Stanford Type B dissections. Emergency departments made up 158 (76%) of transfer departments; 129 (62%) patients had IBP catheters placed. The highest mean systolic blood pressures (SBPs) recorded were 165 mm Hg in the IBP group versus 151 mm Hg when noninvasive blood pressure (NIBP) cuffs were used (P < .01). The mean decrease in SBP during transport was 51 mm Hg in the IBP group versus 34 mm Hg in the NIBP group (P < .001). The difference between the last reported NIBP and the first IBP was noted as 19 mm Hg higher. The IBP group met the SBP goal more frequently than the NIBP group (P < .05) when the SBP was noted as greater than 140 mm Hg during transport. Bedside time increased only 6 minutes with IBP placement (P < .007). CONCLUSION: Patients with IBP catheters were noted to be more aggressively managed with antihypertensive medications, met hemodynamic goals more frequently, and had only 6 minutes longer bedside times. These findings support the placement of IBP catheters by emergency departments and critical care transport (CCT) teams in patients with acute aortic syndromes requiring interfacility transport to definitive care

Multidisciplinary approaches to moving and handling for formal and informal carers in community palliative care

Health professionals such as nurses, physiotherapists and occupational therapists provide a wealth of support in the community to patients and their carers receiving palliative care. Moving and handling is one such support that needs careful consideration and assessment including risk, by appropriately qualified professionals. A combination of skills are required as well as knowledge of up to date equipment to assist the health professional in deciding how to formulate safe moving and handling interventions in a timely way. Patients with palliative care needs and their carers should be given the appropriate care and support necessary using a holistic, flexible and patient-centred approach to service delivery

Trade-offs and synergies in the structural and functional characteristics of leaves photosynthesizing in aquatic environments

Aquatic plants, comprising different divisions of embryophytes, derive from terrestrial ancestors. They have evolved to live in water, both fresh and salty, an environment that presents unique challenges and opportunities for photosynthesis and growth. These include, compared to air, a low water stress, a greater density, and attenuation of light, and a more variable supply of inorganic carbon, both in concentration and chemical species, but overall a lower carbon availability, and the opportunity to take up nutrients from the water. The leaves of many aquatic plants are linear, dissected, whorled, or cylindrical with a large volume of air spaces. They tend to have a high specific leaf area, thin cuticles, and usually lack functional stomata. Exploiting the availability of chemicals in their environment, freshwater macrophytes may incorporate silica in their cell wall, while seagrasses contain sulphated polysaccharides, similar to those of marine macroalgae; both groups have low lignin content. This altered cell wall composition produces plants that are more flexible and therefore more resistant to hydraulic forces (mechanical stress arising from water movement). Aquatic plants may have enhanced light harvesting complexes conferring shade adaptation, but also have mechanisms to cope with high light. Aquatic plants have evolved numerous strategies to overcome potential carbon-limitation in water. These include growing in micro-environments where CO2 is high, producing leaves and roots that exploit CO2 from the air or sediment and operating concentrating mechanisms that increase CO2 (CCM) around the primary carboxylating enzyme, ribulose-1,5-bisphosphate carboxylase-oxygenase. These comprise C4 metabolism, crassulacean acid metabolism, and the ability to exploit the often high concentrations of HCO3−, and ~50% of freshwater macrophytes and ~85% of seagrasses have one or more CCM. Many of these adaptations involve trade-offs between conflictin constraints and opportunities while others represent ‘synergies’ that help to maximize the productivity of this important group of plants