Unraveling the Excited-State Dynamics of Eosin Y Photosensitizers Using Single-Molecule Spectroscopy.

The intersystem crossing and dispersive electron-transfer dynamics of eosin Y (EY) photosensitizers are probed using single-molecule microscopy. The blinking dynamics of EY on glass are quantified by constructing cumulative distribution functions of emissive ("on") and nonemissive ("off") events. Maximum likelihood estimation (MLE) and goodness-of-fit tests based on the Kolmogorov-Smirnov (KS) statistic are used to establish the best fit to the blinking data and differentiate among competitive photophysical processes. The on-time probability distributions for EY in N2 and air are power-law distributed after ∼1 s, with fit parameters that are significantly modified upon exposure to oxygen. By extending the statistically principled MLE/KS approach to include an onset time for log-normal behavior, we demonstrate that the off-time distribution for EY in N2 is best fit to a combination of exponential and log-normal functions. The corresponding distribution for EY in air is best fit to a log-normal function alone. Furthermore, power law and log-normal distributions are observed for an individual molecule in air, consistent with dynamic fluctuations in the rate constant for dark-state population and depopulation. These observations support the interpretation that dispersive electron transfer (i.e., the Albery model) from the first excited singlet state (S1) of EY to trap states on glass is predominately responsible for blinking in oxic conditions. In anoxic environment, both triplet-state blinking and dispersive electron transfer from S1 and the excited triplet state (T1) contribute to the excited-state dynamics of EY.

THISTLE: trial of hands-on Interprofessional simulation training for local emergencies: a research protocol for a stepped-wedge clustered randomised controlled trial.

BACKGROUND: Many adverse pregnancy outcomes in the UK could be prevented with better intrapartum care. Training for intrapartum emergencies has been widely recommended but there are conflicting data about their effectiveness. Observational studies have shown sustained local improvements in perinatal outcomes associated with the use of the PRactical Obstetric Multi-Professional Training - (PROMPT) training package. However this effect needs to be investigated in the context of randomised study design in settings other than enthusiastic early adopter single-centres. The main aim of this study is to determine the effectiveness of PROMPT to reduce the rate of term infants born with low APGAR scores. METHODS: THISTLE (Trial of Hands-on Interprofessional Simulation Training for Local Emergencies) is a multi-centre stepped-wedge clustered randomised controlled superiority trial conducted across 12 large Maternity Units in Scotland. On the basis of prior observational findings all Units have been offered the intervention and have been randomly allocated in groups of four Units, to one of three intervention time periods, each six months apart. Teams of four multi-professional clinicians from each participating Unit attended a two-day PROMPT Train the Trainers (T3) programme prior to the start of their allocated intervention step. Following the T3 training, the teams commenced the implementation of local intrapartum emergency training in their own Units by the start of their allocated intervention period. Blinding has not been possible due to the nature of the intervention. The aim of the study is to follow up each Unit for at least 12-months after they have commenced their local courses. The primary outcome for the study is the proportion of Apgar scores <7 at 5 min for term vaginal or emergency caesarean section births (≥37 weeks) occurring in each of the study Units. These data will be extracted from the Information Services Division Scottish Morbidity Record 02, a national routine data collection on pregnancy and births. Mixed or marginal logistic regression will be employed for the main analysis. DISCUSSION: THISTLE is the first stepped wedge cluster randomised trial to evaluate the effectiveness of an intrapartum emergencies training programme. The results will inform training, trainers and policy going forward. TRIAL REGISTRATION: ISRCTN11640515 (registered on 09/09/2013).

Mastering Femtosecond Stimulated Raman Spectroscopy: A Practical Guide.

Femtosecond stimulated Raman spectroscopy (FSRS) is a powerful nonlinear spectroscopic technique that probes changes in molecular and material structure with high temporal and spectral resolution. With proper spectral interpretation, this is equivalent to mapping out reactive pathways on highly anharmonic excited-state potential energy surfaces with femtosecond to picosecond time resolution. FSRS has been used to examine structural dynamics in a wide range of samples, including photoactive proteins, photovoltaic materials, plasmonic nanostructures, polymers, and a range of others, with experiments performed in multiple groups around the world. As the FSRS technique grows in popularity and is increasingly implemented in user facilities, there is a need for a widespread understanding of the methodology and best practices. In this review, we present a practical guide to FSRS, including discussions of instrumentation, as well as data acquisition and analysis. First, we describe common methods of generating the three pulses required for FSRS: the probe, Raman pump, and actinic pump, including a discussion of the parameters to consider when selecting a beam generation method. We then outline approaches for effective and efficient FSRS data acquisition. We discuss common data analysis techniques for FSRS, as well as more advanced analyses aimed at extracting small signals on a large background. We conclude with a discussion of some of the new directions for FSRS research, including spectromicroscopy. Overall, this review provides researchers with a practical handbook for FSRS as a technique with the aim of encouraging many scientists and engineers to use it in their research.

A randomised clinical trial of intrapartum fetal monitoring with computer analysis and alerts versus previously available monitoring.

BACKGROUND: Intrapartum fetal hypoxia remains an important cause of death and permanent handicap and in a significant proportion of cases there is evidence of suboptimal care related to fetal surveillance. Cardiotocographic (CTG) monitoring remains the basis of intrapartum surveillance, but its interpretation by healthcare professionals lacks reproducibility and the technology has not been shown to improve clinically important outcomes. The addition of fetal electrocardiogram analysis has increased the potential to avoid adverse outcomes, but CTG interpretation remains its main weakness. A program for computerised analysis of intrapartum fetal signals, incorporating real-time alerts for healthcare professionals, has recently been developed. There is a need to determine whether this technology can result in better perinatal outcomes. METHODS/DESIGN: This is a multicentre randomised clinical trial. Inclusion criteria are: women aged ≥ 16 years, able to provide written informed consent, singleton pregnancies ≥ 36 weeks, cephalic presentation, no known major fetal malformations, in labour but excluding active second stage, planned for continuous CTG monitoring, and no known contra-indication for vaginal delivery. Eligible women will be randomised using a computer-generated randomisation sequence to one of the two arms: continuous computer analysis of fetal monitoring signals with real-time alerts (intervention arm) or continuous CTG monitoring as previously performed (control arm). Electrocardiographic monitoring and fetal scalp blood sampling will be available in both arms. The primary outcome measure is the incidence of fetal metabolic acidosis (umbilical artery pH < 7.05, BDecf > 12 mmol/L). Secondary outcome measures are: caesarean section and instrumental vaginal delivery rates, use of fetal blood sampling, 5-minute Apgar score < 7, neonatal intensive care unit admission, moderate and severe neonatal encephalopathy with a marker of hypoxia, perinatal death, rate of internal monitoring, tracing quality, and signal loss. Analysis will follow an intention to treat principle. Incidences of primary and secondary outcomes will be compared between groups. Assuming a reduction in metabolic acidosis from 2.8% to 1.8%, using a two-sided test with alpha = 0.05, power = 0.80, and 10% loss to follow-up, 8133 women need to be randomised. DISCUSSION: This study will provide evidence of the impact of intrapartum monitoring with computer analysis and real-time alerts on the incidence of adverse perinatal outcomes, intrapartum interventions and signal quality. (Current controlled trials ISRCTN42314164).

Effect of hands-on interprofessional simulation training for local emergencies in Scotland: the THISTLE stepped-wedge design randomised controlled trial.

OBJECTIVE: To assess whether the implementation of an intrapartum training package (PROMPT (PRactical Obstetric Multi-Professional Training)) across a health service reduced the proportion of term babies born with Apgar score <7 at 5 min (<75mins). DESIGN: Stepped-wedge cluster randomised controlled trial. SETTING: Twelve randomised maternity units with ≥900 births/year in Scotland. Three additional units were included in a supplementary analysis to assess the effect across Scotland. The intervention commenced in March 2014 with follow-up until September 2016. INTERVENTION: The PROMPT training package (Second edition), with subsequent unit-level implementation of PROMPT courses for all maternity staff. MAIN OUTCOME MEASURES: The primary outcome was the proportion of term babies with Apgar<75mins. RESULTS: 87 204 eligible births (99.2% with an Apgar score), of which 1291 infants had an Apgar<75mins were delivered in the 12 randomised maternity units. Two units did not implement the intervention. The overall Apgar<75mins rate observed in the 12 randomised units was 1.49%, increasing from 1.32% preintervention to 1.59% postintervention. Once adjusted for a secular time trend, the 'intention-to-treat' analysis indicated a moderate but non-significant reduction in the rate of term babies with an Apgar scores <75mins following PROMPT training (OR=0.79 95%CI(0.63 to 1.01)). However, some units implemented the intervention earlier than their allocated step, whereas others delayed the intervention. The content and authenticity of the implemented intervention varied widely at unit level. When the actual date of implementation of the intervention in each unit was considered in the analysis, there was no evidence of improvement (OR=1.01 (0.84 to 1.22)). No intervention effect was detected by broadening the analysis to include all 15 large Scottish maternity units. Units with a history of higher rates of Apgar<75mins maintained higher Apgar rates during the study (OR=2.09 (1.28 to 3.41)) compared with units with pre-study rates aligned to the national rate. CONCLUSIONS: PROMPT training, as implemented, had no effect on the rate of Apgar <75mins in Scotland during the study period. Local implementation at scale was found to be more difficult than anticipated. Further research is required to understand why the positive effects observed in other single-unit studies have not been replicated in Scottish maternity units, and how units can be best supported to locally implement the intervention authentically and effectively. TRIAL REGISTRATION NUMBER: ISRCTN11640515.

A measles outbreak among young adults in Victoria, February 2001.

In January 2001 a 19-year-old Sydney resident, who had recently returned from India, visited Melbourne for 4 days while infectious with measles. A further 50 measles cases were subsequently identified, mainly among young adults. Thirty-eight cases (75%) were in the same birth cohort (born between 1968 and 1981). This cohort was identified as being at high risk of measles infection after a previous outbreak in Victoria involving 75 cases. These individuals are now aged between 20 and 33 years. A high proportion of cases, 22 (43%) were hospitalised after multiple visits to various healthcare providers. None of the cases had documentation of receiving the recommended number of doses of measles-containing vaccine for their age. Repeated outbreaks clearly demonstrate that young adults remain the group at highest risk of measles infection in Victoria. More targeted strategies for young adults and healthcare workers are required to better protect these groups against measles.