Low energy excitations in crystalline perovskite oxides: Evidence from noise experiments

In this paper we report measurements of 1/f noise in a crystalline metallic oxide with perovskite structure down to 4.2K. The results show existence of localized excitations with average activation energy $\approx$ 70-80 meV which produce peak in the noise at T $\approx$ 35-40K. In addition, it shows clear evidence of tunnelling type two-level-systems (as in glasses) which show up in noise measurements below 30K.Comment: 11 pages, 4 figures, to appear in Phys Rev B, vol 58, 1st Dec issu

The management and outcome for patients with chronic subdural hematoma: a prospective, multicenter, observational cohort study in the United Kingdom

Symptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH

The management and outcome for patients with chronic subdural hematoma: A prospective, multicenter, observational cohort study in the United Kingdom

OBJECTIVESymptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH.METHODSData on management and outcomes for patients with CSDH referred to UK and Ireland NSUs were collected prospectively over an 8-month period and audited against criteria predefined from the literature: NSU mortality < 5%, NSU morbidity < 10%, symptomatic recurrence within 60 days requiring repeat surgery < 20%, and unfavorable functional status (modified Rankin Scale score of 4–6) at NSU discharge < 30%.RESULTSData from 1205 patients in 26 NSUs were collected. Bur-hole craniostomy was the most common procedure (89%), and symptomatic recurrence requiring repeat surgery within 60 days was observed in 9% of patients. Criteria on mortality (2%), rate of recurrence (9%), and unfavorable functional outcome (22%) were met, but morbidity was greater than expected (14%). Multivariate analysis demonstrated that failure to insert a drain intraoperatively independently predicted recurrence and unfavorable functional outcome (p = 0.011 and p = 0.048, respectively). Increasing patient age (p < 0.00001), postoperative bed rest (p = 0.019), and use of a single bur hole (p = 0.020) independently predicted unfavorable functional outcomes, but prescription of high-flow oxygen or preoperative use of antiplatelet medications did not.CONCLUSIONSThis is the largest prospective CSDH study and helps establish national standards. It has confirmed in a real-world setting the effectiveness of placing a subdural drain. This study identified a number of modifiable prognostic factors but questions the necessity of some common aspects of CSDH management, such as enforced postoperative bed rest. Future studies should seek to establish how practitioners can optimize perioperative care of patients with CSDH to reduce morbidity as well as minimize CSDH recurrence. The BNTRC is unique worldwide, conducting multicenter trainee-led research and audits. This study demonstrates that collaborative research networks are powerful tools to interrogate clinical research questions.Society of British Neurological Surgeons. PJH supported by NIHR Research Professorship and NIHR Cambridge Biomedical Research Centre.This is the author accepted manuscript. It is permanently embargoed to comply with the publisher’s copyright terms. The final version is available via https://doi.org/10.3171/2016.8.JNS1613

Outcomes following surgery in subgroups of comatose and very elderly patients with chronic subdural hematoma

Increasing age and lower pre-operative Glasgow coma score (GCS) are associated with worse outcome after surgery for chronic subdural haematoma (CSDH). Only few studies have quantified outcomes specific to the very elderly or comatose patients. We aim to examine surgical outcomes in these patient groups. We analysed data from a prospective multicentre cohort study, assessing the risk of recurrence, death, and unfavourable functional outcome of very elderly (≥ 90 years) patients and comatose (pre-operative GCS ≤ 8) patients following surgical treatment of CSDH. Seven hundred eighty-five patients were included in the study. Thirty-two (4.1%) patients had pre-operative GCS ≤ 8 and 70 (8.9%) patients were aged ≥ 90 years. A higher proportion of comatose patients had an unfavourable functional outcome (38.7 vs 21.7%; p = 0.03), although similar proportion of comatose (64.5%) and non-comatose patients (61.8%) functionally improved after surgery (p = 0.96). Compared to patients aged < 90 years, a higher proportion of patients aged ≥ 90 years had unfavourable functional outcome (41.2 vs 20.5%; p < 0.01), although approximately half had functional improvement following surgery. Mortality risk was higher in both comatose (6.3 vs 1.9%; p = 0.05) and very elderly (8.8 vs 1.1%; p < 0.01) groups. There was a trend towards a higher recurrence risk in the comatose group (19.4 vs 9.5%; p = 0.07). Surgery can still provide considerable benefit to very elderly and comatose patients despite their higher risk of morbidity and mortality. Further research would be needed to better identify those most likely to benefit from surgery in these groups

A case of spontaneous haematoma from vertebral artery arterio-venous fistula in a patient with neurofibromatosis type 1

peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=ibjn2

Development of a laboratory model of activated charcoal-nitrogen adsorption cryocooler

The development of a laboratory model of a charcoal-nitrogen adsorption cryocooler is described. The results on characterization of various components of this cooler and performance of the ensemble are presented. Four compressor cells are operated 90° out of phase to generate 0.0364 g/s (1.75 slpm) of nitrogen at a pressure of 5.2 MPa. The cycle time per compressor was 8 min, equally apportioned between heating and cooling. The high pressure gas is pre-cooled to 193 K and expanded through a J-T/heat exchanger assembly. A cold tip temperature of 124 K is obtained at a parasitic heat load of 0.36 W