Terahertz spectroscopy: a powerful new tool for the chemical sciences?

Terahertz spectroscopy is only now beginning to make its transition from initial development by physicists and engineers to broader use by chemists, materials scientists and biologists, thanks to the increasing availability of commercial terahertz spectrometers. With the unique insights that terahertz spectroscopy can provide into intermolecular bonding and crystalline matter, it could prove to be an invaluable addition to the chemist's analytical toolset. This tutorial review aims to give an introduction to terahertz spectroscopy, its techniques, equipment, current applications and potential for the chemical sciences to a broad readership.

Recent advances in catalytic asymmetric epoxidation using the environmentally benign oxidant hydrogen peroxide and its derivatives

There has been a recent drive to develop asymmetric catalytic methods to produce epoxides using environmentally benign oxidants, especially hydrogen peroxide. This critical review discusses the advances that have been made using both metal-based and organocatalytic homogeneous catalysts (142 references).

Improving neonatal unit admission temperatures in preterm babies: exothermic mattresses, polythene bags or a traditional approach?

OBJECTIVE

To investigate whether exothermic sodium acetate mattresses were associated with an improvement in the thermal care of babies <30 weeks gestation between birth and admission to a neonatal unit.

STUDY DESIGN

Analysis of a three case series of babies: the first with traditional thermal care of drying and wrapping in a towel, the second with wrapping in food standard polythene bags and the third with wrapping in polythene bags and nursing on an activated exothermic mattress. The main outcome measure was the temperature on admission to the neonatal unit.

RESULT

There were no significant differences between the groups for gestation and birth weight. Hypothermia was less frequent in the 'bag and mattress' group compared with the 'bag only' and traditional care groups (26 vs 69 vs 84%, respectively) even though the median time to admission was longest in the 'bag and mattress' group (23 min). The proportions of babies admitted with temperatures in the target range of 36.5 to 37.5 degrees C were 46, 27 and 16%, respectively. Multiple regression analysis showed that use of the mattress raised admission temperatures by 1.04 degrees C. The median temperature of babies in the 'bag and mattress' group was higher compared with the other groups (36.9 vs 36.0 vs 35.8 degrees C), but significantly more were hyperthermic (28 vs 4 and 0.4%, respectively).

CONCLUSION

Use of exothermic mattresses for babies <30 weeks gestation was associated with a significantly greater proportion of babies being admitted to the neonatal unit with a temperature in the euthermic range, but there was also an increased risk of hyperthermia.

Is there really a diagnostically useful relationship between the carbon-oxygen stretching frequencies in metal carboxylate complexes and their coordination mode?

An investigation into the relationship between the asymmetric and symmetric stretching modes of ancillary carboxylate ligands and their mode of binding in a family of manganese(III) complexes of tetradentate N(2)O(2) Schiff base ligands, which includes comparison of an (18)O isotopically labelled derivative, has been undertaken. The results suggest that caution should be employed in using this technique to assign the binding mode of the carboxylate ligands in these complexes despite its very extensive use in the literature.

A synthetically simple, click-generated cyclam-based zinc(II) sensor

A cyclam-based macrocyclic sensor has been prepared using synthetically simple "click" chemistry to link a fluorophore to the macrocyclic receptor. This sensor shows high selectivity for Zn(II) over a range of other metals, providing a significant enhancement of fluorescence intensity over a wide pH range. As such, this is the first cyclam-based sensor demonstrated to be selective for Zn(II) and is the first example of a triazole being used as a coordinating ligand on an azamacrocycle. The sensor can access biologically available zinc in mammalian cells, sensing the Zn(II) flux that exists during apoptotic cell death.

Temperature management in the delivery room

After being in a relatively stable thermoneutral uterus for the whole of pregnancy, the newborn baby enters a cooling environment and might suffer significant heat loss and hypothermia in the first minutes of life. Alternatively, the fetus might face significant hyperthermia during and immediately after delivery if the mother is febrile. Hypothermia, particularly in preterm babies, is associated with increased morbidity and mortality. Hyperthermic babies have a worse short-term outcome, and hyperthermia can be particularly detrimental in association with intrapartum asphyxia and infection. Prevention and treatment of these variations in temperature are still developing and the efficacy of some strategies remains unclear. Nevertheless, one goal in the delivery room is to maintain the newborn baby's temperature within the physiologically optimum range.

Effective Methods for the Biotinylation of Azamacrocycles

The biotin-(strept)avidin interaction remains a gold standard of model biological recognition events. The biotinylation of azamacrocycles permits the investigation of signal transduction between this recognition event and the metal center of an azamacrocycle complex, of wide potential interest in biosensing. There are no generally applicable procedures in the literature for such functionalizations. We report here a comprehensive investigation into the attachment of biotin to TACN, cyclen, and cyclam. Effective methods have been found for each ring. The efficacy of the functionalization is critically dependent on the nature of the azamacrocycle.

Sucrose and non-nutritive sucking for the relief of pain in screening for retinopathy of prematurity: a randomised controlled trial

BACKGROUND

Screening is necessary for infants at risk of retinopathy of prematurity. Despite local anaesthetic drops, infants find eye examinations distressing, displaying behavioural and physiological changes indicating acute pain. Oral sucrose and non-nutritive sucking reduce pain responses associated with invasive procedures.

OBJECTIVE

To evaluate the use of oral sucrose and/or pacifier for reducing pain responses during eye examinations.

METHODS

Forty infants <32 weeks gestation or <1500 g birth weight, in two neonatal units, were randomised to one of four interventions administered two minutes before their first screening examination: 1 ml sterile water as placebo (group 1, n = 10), 1 ml 33% sucrose solution (group 2, n = 10), 1 ml sterile water with pacifier (group 3, n = 9), or 1 ml 33% sucrose solution with pacifier (group 4, n = 11). Examinations were videotaped. Two observers, blind to the intervention, assessed recordings. Pain responses were scored using the premature infant pain profile (PIPP).

RESULTS

The groups were similar in gestation, birth weight, and age at examination. Mean PIPP scores were 15.3, 14.3, 12.3, and 12.1 for groups 1, 2, 3, and 4 respectively. Analysis of variance showed a significant difference in PIPP score between groups (p = 0.023). Infants randomised to pacifiers scored lower than those without pacifiers (p = 0.003). There was no difference between groups receiving sucrose and those receiving water (p = 0.321).

CONCLUSIONS

Non-nutritive sucking reduced distress responses in infants undergoing screening for retinopathy of prematurity. The difference in response was large enough to be detected by a validated assessment tool. No synergistic effect of sucrose and pacifier was apparent in this group.

Temperature control of premature infants in the delivery room

The body temperature of preterm babies can drop precipitously after delivery, and this hypothermia is associated with an increase in mortality and morbidity. Reports of hypothermia in babies of all birth weights, on admission to neonatal units, have come from all over the world; most also report increased mortality in association with hypothermia. Recent reports that showed that hypothermia on admission to neonatal units is an independent risk factor for mortality in preterm babies have refocused attention on the need for meticulous thermal care immediately after birth and during resuscitation. Their data lend weight to the view that conventional approaches to thermal care of the very preterm and low birth weight baby are outmoded.

The application of manganese complexes of ligands derived from 1,4,7-triazacyclononane in oxidative catalysis

Since the disclosure that manganese complexes of certain azamacrocyclic ligands were potent low-temperature bleaching catalysts, considerable effort has focussed on their development towards the efficient catalytic oxidation of other substrates, principally with the environmentally benign oxidant H(2)O(2). These efforts have resulted in a broad substrate scope for the system, including alkenes (to give both epoxides and cis-diols as potential products), alcohols, sulfides and C-H oxidation. Additional developments include the heterogenisation of catalytic systems as well as the first generation of enantiomerically pure ligand systems for application in asymmetric epoxidation catalysis. To date there has only been modest success in this regard, but as our understanding of the nature of the active oxidant(s) continues to develop it is likely that there will be viable applications for these systems in the near future.