Nonlinear pulse compression based on a gas-filled multipass cell

We demonstrate nonlinear temporal compression of a high-energy Yb-doped fiber laser source in a multipass cell filled with argon. The 160 μJ 275 fs input pulses are compressed down to 135 μJ 33 fs at the output, corresponding to an overall transmission of 85%. We also analyze the output beam, revealing essentially no space-time couplings. We believe this technique can be scalable to higher pulse energies and shorter pulse durations, enabling access to a wider parameter range for a large variety of ultrafast laser sources.

An incidental finding of severe hyperferritinaemia: a lesson to be learned

Haemophagocytic lymphohistiocytosis is a rare, under-recognised and often misdiagnosed condition, characterised by a hyperinflammatory response to malignancy or infection. In this case, the cause was a bone marrow isolated anaplastic large cell lymphoma without radiological evidence of systemic disease, a phenomenon rarely described. We present the case of a previously fit and well 64-year-old female who presented on multiple occasions to primary and secondary care in a stable condition with an undifferentiated illness with the only consistent feature being a marked, unexplained hyperferritinaemia. The history highlights the importance of ferritin as a marker of phagocytic activity and how severely high levels, even in the well patient, should prompt early bone marrow biopsy. The prognosis of haemophagocytic lymphohistiocytosis is invariably poor as the condition is usually secondary to a serious underlying disease such as haematological malignancy as in this case. The diagnostic difficulty often leads to delayed recognition and treatment.

How long can a waiting list be?

Aims and Method

Quantifying the relationship between waiting time and clinic attendance in child and adolescent psychiatry would allow better estimation of the resources needed to eliminate waiting lists in specific initiatives. All cases on a waiting list were sent a questionnaire, return of the questionnaire being necessary for an appointment to be made. Those who did not return the questionnaire or did not attend were contacted and a reason obtained whenever possible. The data were analysed using Cox regression.

Results

Most who did not return their questionnaires had been waiting less than four weeks or longer than 30 weeks. Questionnaire return seemed a good estimate of intention to attend. Other factors improving questionnaire return were younger patient age, previous experience of the service, a clear common reason for referral, and a non-general practitioner referral source.

Clinical Implications

Waiting lists in child and adolescent psychiatry may have a natural ‘endpoint’ at 30 weeks beyond which families give up, while waiting lists of less than one-month may be too short to lose transient problems. Failure to include this and other indicators of non-attendance may lead to overestimates of resources needed to remove queues for treatment. Questionnaires may be useful in identifying those intending to attend.

Neonatal Acute Kidney Injury: A Survey of Neonatologists' and Nephrologists' Perceptions and Practice Management

BACKGROUND

Neonatal acute kidney injury (AKI) occurs in 40 to 70% of critically ill neonatal intensive care admissions. This study explored the differences in perceptions and practice variations among neonatologists and pediatric nephrologists in diagnostic criteria, management, and follow-up of neonatal AKI.

METHODS

A survey weblink was emailed to nephrologists and neonatologists in Australia, Canada, New Zealand, India, and the United States. Questions consisted of demographic and unit practices, three clinical scenarios assessing awareness of definitions of neonatal AKI, knowledge, management, and follow-up practices.

RESULTS

Many knowledge gaps among neonatologists, and to a lesser extent, pediatric nephrologists were identified. Neonatologists were less likely to use categorical definitions of neonatal AKI (p < 0.00001) or diagnose stage 1 AKI (p < 0.00001) than pediatric nephrologists. Guidelines for creatinine monitoring for nephrotoxic medications were reported by 34% (aminoglycosides) and 62% (indomethacin) of respondents. Nephrologists were more likely to consider follow-up after AKI than neonatologists (p < 0.00001). Also, 92 and 86% of neonatologists and nephrologists, respectively, reported no standardization or infrastructure for long-term renal follow-up.

CONCLUSION

Neonatal AKI is underappreciated, particularly among neonatologists. A lack of evidence on neonatal AKI contributes to this variation in response. Therefore, dissemination of current knowledge and areas for research should be the priority.