Spectroscopic Study into Lanthanide Speciation in Deep Eutectic Solvents.

Deep eutectic solvents are a new class of green solvents that are being explored as an alternative for used nuclear fuel and critical material recycling. However, there is a paucity of knowledge regarding metal behavior in them. This paper explores the underlying chemistry of rare-earth elements in choline chloride-based deep eutectic solvents by using a multi-technique spectroscopic methodology. Results show that speciation is highly dependent on the choice of the hydrogen-bond donor. Collected EXAFS data showed Ln3+ coordination with ethylene glycol and urea in their respective solvents and coordination with chloride in the lactic acid system. Generalized coordination environments were determined to be [LnL4-5], [LnL7-10], and [LnL5-6] in the ethylene glycol, urea, and lactic acid systems, respectively. Collected UV/vis spectra for Nd3+ and Er3+ showed variations with changing solvents, showing that Ln-Cl interactions do not dominate in these systems. Luminescence studies were consistent, showing varying emission spectra with varying solvent systems. The shortest luminescent lifetimes were observed in the choline chloride-ethylene glycol deep eutectic solvent, suggesting coordination through O-H groups. Combining all collected data allowed Eu3+ coordination geometries to be assigned.

Improved spatio-temporal measurements of visually evoked fields using optically-pumped magnetometers.

Recent developments in performance and practicality of optically-pumped magnetometers (OPMs) have enabled new capabilities in non-invasive brain function mapping through magnetoencephalography. In particular, the lack of cryogenic operating conditions allows for more flexible placement of sensor heads closer to the brain, leading to improved spatial resolution and source localisation capabilities. Through recording visually evoked brain fields (VEFs), we demonstrate that the closer sensor proximity can be exploited to improve temporal resolution. We use OPMs, and superconducting quantum interference devices (SQUIDs) for reference, to measure brain responses to flash and pattern reversal stimuli. We find highly reproducible signals with consistency across multiple participants, stimulus paradigms and sensor modalities. The temporal resolution advantage of OPMs is manifest in a twofold improvement, compared to SQUIDs. The capability for improved spatio-temporal signal tracing is illustrated by simultaneous vector recordings of VEFs in the primary and associative visual cortex, where a time lag on the order of 10-20 ms is consistently found. This paves the way for further spatio-temporal studies of neurophysiological signal tracking in visual stimulus processing, and other brain responses, with potentially far-reaching consequences for time-critical mapping of functionality in healthy and pathological brains.

Preference for place of care and place of death in palliative care: are these different questions?

Place of death is at times suggested as an outcome for palliative care services. This study aimed to describe longitudinal preferences for place of care and place of death over time for patients and their caregivers. Longitudinal paired data of patient/caregiver dyads from a prospective unblinded cluster randomised control trial were used. Patients and caregivers were separately asked by the palliative care nurse their preference at that time for place of care and place of death. Longitudinal changes over time for both questions were mapped; patterns of agreement (patient and caregiver; and preference for place of death when last asked and actual placed of death) were analysed with kappa statistics. Seventy-one patient/caregiver dyads were analysed. In longitudinal preferences, preferences for both the place of care (asked a mean of >6 times) and place of death (asked a mean of >4 times) changed for patients (28% and 30% respectively) and caregivers (31% and 30%, respectively). In agreement between patients and caregivers, agreement between preference of place of care and preferred place of death when asked contemporaneously for patients and caregivers was low [56% (kappa 0.33) and 36% (kappa 0.35) respectively]. In preference versus actual place of death, preferences were met for 37.5% of participants for home death; 62.5% for hospital; 76.9% for hospice and 63.6% for aged care facility. This study suggests that there are two conversations: preference for current place of care and preference for care at the time of death. Place of care is not a euphemism for place of death; and further research is needed to delineate these. Patient and caregiver preferences may not change simultaneously. Implications of any mismatch between actual events and preferences need to be explored.

A prospective study of the impact of community-based azithromycin treatment of trachoma on carriage and resistance of Streptococcus pneumoniae.

In February 1995, single-dose azithromycin was given to children with trachoma and their household contacts who were children. For children with trachoma, rates of carriage of pneumococci immediately before treatment with azithromycin and 2-3 weeks, 2 months, and 6 months after treatment were 68% (54 of 79), 29% (11 of 38), 78% (29 of 37), and 87% (34 of 39), respectively. The proportion of carriage-positive children with azithromycin-resistant Streptococcus pneumoniae strains was 1 of 54 (1.9%) before treatment and then 6 of 11 (54.5%), 10 of 29 (34.5%), and 2 of 34 (5.9%) at follow-up visits. The profile of pneumococcal serotypes changed after azithromycin treatment. Azithromycin-resistant strains (serotypes 10F, 23A, and 45) were isolated from 1 (1.3%) of 79 pretreatment swab specimens, from 16 (21.3%) of 75 swab specimens collected up to 2 months after treatment, and from 2 (6%) of 32 obtained 6 months after treatment. Mathematical modeling showed a more rapid appearance of azithromycin-resistant pneumococcal strains in previously colonized children than in previously noncolonized children. Thus, it appears that the selective effect of azithromycin allowed the growth and transmission of preexisting azithromycin-resistant strains. More research is needed to clarify the clinical relevance and implications of azithromycin use.

Carriage of multiple ribotypes of non-encapsulated Haemophilus influenzae in aboriginal infants with otitis media.

Ribotyping with the restriction enzyme XbaI was used to study the dynamics of Carriage of non-encapsulated Haemophilus influenzae (NCHi) in Aboriginal infants at risk of otitis media. Carriage rates of NCHi in the infants in the community were very high; the median age for detection was 50 days and colonization was virtually 100% by 120 days of age and persisted at a high level throughout the first year of life [1]. Eighteen different ribotypes of NCHi were identified from 34 positive swabs taken from 3 infants over a period of 9 months. The same ribotypes were recovered for up to 3 months from consecutive swabs of individual infants, and 12 of 27 swabs (44.4%) yielded two ribotypes from four colonies typed. Statistical analysis suggested that most swabs would have been positive for two ribotypes if enough colonies had been typed although the second most frequent ribotype was detected on average in only 13% of strains. Early colonization and carriage of multiple ribotypes of NCHi may help to explain the chronicity of carriage and thus the persistence of otitis media in Aboriginal infants.

Comparison of hemoglobin A1c and hemoglobin A1 in diabetic patients.

Hemoglobin A1 (HbA1) and hemoglobin A1c (HbA1c) values were compared in 934 samples from 686 subjects with diabetes mellitus. Linear regression analysis revealed the two parameters to be highly related with HbA1 = 1.18 HbA1c + 1.67, and a correlation coefficient of 0.97. Samples with HbA1 greater than predicted from the measured HbA1c had been stored significantly longer (approximately 1 day) than other samples, suggesting that sample storage may slightly alter the relationship between these parameters. Serial HbA1 and HbA1c values in all 9 patients for whom data was available from at least 5 time points changed in parallel regardless of the time interval between sampling or the magnitude of the interval change of HbA1c and HbA1. These data indicate that the potentially simpler measurement of HbA1 gives results equivalent to HbA1c for clinical applications.

The foramen ovale and sphenoidal angle in man.

The structure of the greater wing of the sphenoid in the region of the foramen ovale and sphenoidal angle is described in both the adult human and in two partly ossified human embryos. It is shown that the foramen ovale of man is enclosed by membrane bone, derived from a medial process associated with the scaphoid fossa, and a lateral tongue, the most dorsal part of which is present in many adults as a process on the lateral margin of the foramen. These structures are parts of an extensive membrane bone which forms the larger part of the greater wing of the sphenoid. It is shown that the foramen of Vesalius represents the site of fusion between this membrane bone and the more medial, cartilaginous, ala temporalis. Various inconstant patterns of grooves and foramina in the vicinity of the foramen ovale can be interpreted as arising from the interplay of the various parts of the membrane bone and the emissary venous plexus from the middle meningeal veins to the pterygoid plexus. The embryonic anlagen of the pterygo-sphenoidal and pterygo-spinous ligaments are described, and the association of these structures with the parts of the membrane bone are discussed.

Electron microscopy studies of papillary interstitial granules in normal human kidneys.

The papillae of five kidneys from four heart-beating cadaver donors (one child and three young adults) were studied using electron microscopy (EM) technique. The kidneys were made available for EM study after they were found unsuitable for transplantation owing to low antigen match. All papillae had interstitial cells (IC), stellate processes, and intracellular and free granules. The three types of granules observed were (1) homogeneously dark, (2) gray and (3) layered; the free (outside the IC) granules were identical to the granules within the IC. The child kidney had more IC but fewer granules than the adult kidneys. The granules are ultrastructurally identical to those found in the rat renal papilla. Since rat renal papillary granules have been implicated as the source of renal vasodepressor substance(s), this ultrastructural resemblance suggests that human papillary interstitial granules likewise may be the source renal vasodepressor substance.

Effects of acute and chronic splenectomy on experimental acute renal tubular lesions.

The first half of this study describes the effects of acute splenectomy on epinephrine-induced ATL in the dog. Renal morphology and hematocrit were compared in 12 dogs without splenectomy (group I), six dogs with antecedent splenectomy (group II), and seven dogs with antecedent splenectomy after splenic contraction was induced by topical application of epinephrine (group III). Splenectomy was performed in groups II and III 20 to 30 min prior to epinephrine infusion; all three groups received equal infusions (4 microgram/kg/min) for 6 hr before the kidneys were harvested. ATL and renal congestion were consistently severe in group I but infrequent and less severe in groups II and III. The second half of this study describes the apparent protective effect of chronic (2-week) splenectomy on epinephrine-induced ATL. Renal morphology and hematocrits were compared in 13 intact dogs (group IV) and 10 dogs splenectomized 2 weeks before the epinephrine infusion (group V). The severity of the ATL and the degree of renal congestion were significantly less in the chronically splenectomized dogs. This chronic protection afforded by acute and chronic splenectomy observed after epinephrine infusion remains unclear.