Increased Ion Temperature and Neutron Yield Observed in Magnetized Indirectly Driven D_{2}-Filled Capsule Implosions on the National Ignition Facility.

The application of an external 26 Tesla axial magnetic field to a D_{2} gas-filled capsule indirectly driven on the National Ignition Facility is observed to increase the ion temperature by 40% and the neutron yield by a factor of 3.2 in a hot spot with areal density and temperature approaching what is required for fusion ignition [1]. The improvements are determined from energy spectral measurements of the 2.45 MeV neutrons from the D(d,n)^{3}He reaction, and the compressed central core B field is estimated to be ∼4.9 kT using the 14.1 MeV secondary neutrons from the D(T,n)^{4}He reactions. The experiments use a 30 kV pulsed-power system to deliver a ∼3 µs current pulse to a solenoidal coil wrapped around a novel high-electrical-resistivity AuTa_{4} hohlraum. Radiation magnetohydrodynamic simulations are consistent with the experiment.

Acute paraspinal compartment syndrome as a rare cause of loin pain.

A significant proportion of emergency urological admissions are comprised of ureteric colic presenting as loin pain. A variety of alternative pathologies present in this manner and should be considered during systematic assessment. We report the case of a patient admitted with severe unilateral back and flank pain after strenuous deadlift exercise. Clinical examination and subsequent investigation following a significant delay demonstrated acute paraspinal compartment syndrome (PCS) after an initial misdiagnosis of ureteric colic. The patient was managed conservatively. We review the current literature surrounding the rare diagnosis of PCS and discuss the management options.

Comparisons of dense-plasma-focus kinetic simulations with experimental measurements.

Dense-plasma-focus (DPF) Z-pinch devices are sources of copious high-energy electrons and ions, x rays, and neutrons. The mechanisms through which these physically simple devices generate such high-energy beams in a relatively short distance are not fully understood and past optimization efforts of these devices have been largely empirical. Previously we reported on fully kinetic simulations of a DPF and compared them with hybrid and fluid simulations of the same device. Here we present detailed comparisons between fully kinetic simulations and experimental data on a 1.2 kJ DPF with two electrode geometries, including neutron yield and ion beam energy distributions. A more intensive third calculation is presented which examines the effects of a fully detailed pulsed power driver model. We also compare simulated electromagnetic fluctuations with direct measurement of radiofrequency electromagnetic fluctuations in a DPF plasma. These comparisons indicate that the fully kinetic model captures the essential physics of these plasmas with high fidelity, and provide further evidence that anomalous resistivity in the plasma arises due to a kinetic instability near the lower hybrid frequency.

Design and initial results from a kilojoule level Dense Plasma Focus with hollow anode and cylindrically symmetric gas puff.

We have designed and built a Dense Plasma Focus (DPF) Z-pinch device using a kJ-level capacitor bank and a hollow anode, and fueled by a cylindrically symmetric gas puff. Using this device, we have measured peak deuteron beam energies of up to 400 keV at 0.8 kJ capacitor bank energy and pinch lengths of ∼6 mm, indicating accelerating fields greater than 50 MV/m. Neutron yields of on the order of 10(7) per shot were measured during deuterium operation. The cylindrical gas puff system permitted simultaneous operation of DPF with a radiofrequency quadrupole accelerator for beam-into-plasma experiments. This paper describes the machine design, the diagnostic systems, and our first results.

Glucocorticoids increase protein carbonylation and mitochondrial dysfunction.

Many major psychiatric illnesses have been associated with excessive and prolonged release of glucocorticoid stress hormones potentially leading to deleterious neuronal effects. Recent studies have suggested that oxidative stress is associated with psychiatric illnesses. Oxidative stress is an overproduction of reactive oxygen species (ROS) that overwhelms the cellular antioxidant capacity. The mitochondria are responsible for most oxygen consumption and are a major source of ROS production. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase also contributes significantly to ROS production. This study aims to elucidate the effects of glucocorticoids on oxidative damage to protein, mitochondrial function, NADPH oxidase activity, and antioxidant capacity. Rat pheochromocytoma PC12 cells were treated with corticosterone at concentrations of 0.031, 0.063, and 0.125 mmol/l for 24 h. Protein carbonylation, activities of mitochondrial complex I and III, activity of NADPH oxidase, total antioxidant capacity, and activities of superoxide dismutase (SOD) and catalase (CAT) were analyzed. We found that chronic treatment with corticosterone increased the amount of protein carbonylation in PC12 cells. Complex I activity was decreased with corticosterone treatment, while no change was seen in complex III activity or NADPH oxidase activity. Total antioxidant capacity was increased at the lowest dosage level tested. Although corticosterone treatment had no effect on CAT activity, corticosterone at the highest dosage significantly decreased SOD activity. These results suggest that excessive glucocorticoid activity can increase oxidative damage to protein, possibly by inhibiting activities of mitochondrial complex I and antioxidant enzyme SOD.

Fully kinetic simulations of dense plasma focus Z-pinch devices.

Dense plasma focus Z-pinch devices are sources of copious high energy electrons and ions, x rays, and neutrons. The mechanisms through which these physically simple devices generate such high-energy beams in a relatively short distance are not fully understood. We now have, for the first time, demonstrated a capability to model these plasmas fully kinetically, allowing us to simulate the pinch process at the particle scale. We present here the results of the initial kinetic simulations, which reproduce experimental neutron yields (~10(7)) and high-energy (MeV) beams for the first time. We compare our fluid, hybrid (kinetic ions and fluid electrons), and fully kinetic simulations. Fluid simulations predict no neutrons and do not allow for nonthermal ions, while hybrid simulations underpredict neutron yield by ~100x and exhibit an ion tail that does not exceed 200 keV. Only fully kinetic simulations predict MeV-energy ions and experimental neutron yields. A frequency analysis in a fully kinetic simulation shows plasma fluctuations near the lower hybrid frequency, possibly implicating lower hybrid drift instability as a contributor to anomalous resistivity in the plasma.

Pre-transplant myeloid dendritic cell deficiency associated with cytomegalovirus infection and death after kidney transplantation.

BACKGROUND: Dendritic cells (DCs) are potent antigen-presenting cells critical for immunity. We previously demonstrated a significant association between pre-transplant blood myeloid dendritic cell (mDC) and plasmacytoid dendritic cell (pDC) deficiency and post-transplant BK viremia in renal transplant recipients. In the current post-hoc analysis, we studied the association of these same pre-transplant DC levels with other post-transplant outcomes. METHODS: Pre-transplant peripheral blood mDC and pDC levels were quantified using flow cytometry in 78 patients undergoing kidney transplantation. Post-transplant outcomes were analyzed, including infection, rejection, and patient death, with a median follow-up of 5.3 years. Associations between DC levels and outcomes were assessed using logistic regression analysis and Cox proportional hazards models. RESULTS: An independent association of mDC levels with post-transplant cytomegalovirus infection (adjusted odds ratio 7.0, P = 0.01) and patient death (adjusted hazard ratio 13.0, P = 0.015) was found. No associations were demonstrated between levels of either DC subtype and bacterial infections or rejection. CONCLUSIONS: Pre-transplant mDC deficiency is significantly associated with CMV infection and death after kidney transplantation.

A questionnaire survey on attitudes and understanding towards mental disorders.

OBJECTIVES. To obtain information about basic knowledge towards mental disorders and to evaluate public attitudes towards mental disorders in the Hong Kong Chinese population. METHODS. Questionnaires which collected basic demographic information, opinions about potential stigmas and myths, and knowledge on case vignettes depicting fictional characters with symptoms of mental illness were delivered to subjects in a secondary school, 2 homes for the elderly, a private housing estate, and a public housing estate in Hong Kong. RESULTS. Completed questionnaires were collected from 1035 subjects. In general, the participants' acceptance of mental illness was good. Regular contacts with such patients were associated with better knowledge (t = -2.71, p < 0.01) and better acceptance (t = 2.77, p < 0.01) of mental illness. Younger participants aged 15 to 19 years had a lower level of knowledge about mental health problems compared with other age-groups (p < 0.001). CONCLUSIONS. Personal contact with people with mental illness may help to improve knowledge and acceptance. Younger people in secondary school should be the target and prioritised group for mental health education. Apart from the delivery of mental health knowledge, strategies to increase social contact of the public with people having mental illness could be considered in the design and implementation of anti-stigma programmes.

Computed tomography versus ureteroscopy in identification of renal tract stone with ureteral stent in situ.

INTRODUCTION: The aim of this study was to validate the use of non-contrast computed tomography (CT) with a ureteral stent in situ instead of ureteroscopy for identification of renal tract stones. METHODS: All patients who had stents inserted for renal tract stones and underwent non-contrast CT with the stent in situ followed by ureteroscopy between May 2008 and October 2009 at The Canberra hospital, Australia, were analysed retrospectively. Statistical analysis was performed to compare any differences between CT and ureteroscopy in the identification of stones. RESULTS: Overall, 57 patients were included in the study. The difference between CT and ureteroscopy findings was statistically significant. CT identification of stones with a stent in situ had a sensitivity of 86%, a specificity of 46%, a positive predictive value of 63%, a negative predictive value of 76% and an accuracy of 67%. CONCLUSIONS: Our study suggests that non-contrast CT is inferior to the 'gold standard' of ureteroscopy. It lacks sensitivity, specificity, positive predictive value, negative predictive value and accuracy. Therefore, we cannot recommend using non-contrast CT to replace ureteroscopy.

An unusual cause of nasal airway obstruction in a neonate: trans-sellar, trans-sphenoidal cephalocoele.

INTRODUCTION: Neonates are obligate nasal breathers, and nasal obstruction may have serious implications. We present an extremely rare cause of neonatal nasal obstruction, and its management. CASE REPORT: An eight-day-old neonate was referred for upper airway obstruction. Initial investigations had identified no obvious cause. Rigid airway endoscopy revealed a large, cystic lesion appearing to arise from the roof of the posterior nasal space. Computed tomography and magnetic resonance imaging indicated a basal cephalocoele projecting inferiorly into the oropharynx, with an intracranial connection to the pituitary fossa. Histology showed fibrovascular tissue lined on one aspect by respiratory type epithelium, with mucous glands present. The tissue contained multiple cystic spaces lined by choroid plexus epithelium, with glial tissue present in the walls of the mass. A transpalatal excision of the nasopharyngeal cephalocoele, with closure of the intracranial connection, palatal repair and lumbar drain placement was undertaken. Post-operative recovery was uneventful, with no evidence of cerebrospinal fluid leakage or palatal dysfunction. CONCLUSION: This surgical approach gave excellent access whilst avoiding the obvious morbidity associated with an intracranial approach. Nasal masses should be considered in the differential diagnosis of neonatal respiratory distress due to nasal obstruction.

Thoracic spinal gout mimicking metastasis.

Gout is a common metabolic disease but spinal gout is rare. We report a case of gouty arthritis affecting the thoracic spine in a 76-year-old male patient with a long history of tophaceous gout who presented with bilateral lower limb weakness. Magnetic resonance imaging of his thoracic spine revealed erosions in the left pedicles of T8 and T10. The initial imaging diagnosis was metastatic disease. A computed tomography-guided biopsy of the T10 lesion was performed and confirmed the diagnosis of gout. We advocate the use of computed tomography-guided fine-needle aspiration/biopsy for diagnosing spinal gout because the imaging features are non-specific, metastasis and spondylodiscitis being important mimickers.

Compact collimated fiber optic array diagnostic for railgun plasmas.

We developed and tested a compact collimated 16 channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with approximately millimeter spatial and submicrosecond temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore fixed hybrid armature experiment are presented and compared with one-dimensional simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

Rehabilitation in primary and metastatic brain tumours: impact of functional outcomes on survival.

OBJECTIVES: Patients with brain tumours have major disabilities and guarded prognosis but may benefit from inpatient rehabilitation.The objectives were to compare functional outcomes inpatients with glioblastoma multiforme(GBM), brain metastases and other brain tumours, and to determine predictors of survival. METHODS: Demographic, clinical,functional, and survival data were collected for 63 patients.Kaplan-Meier and Cox regression were used for survival analyses. RESULTS: Functional Independence Measure(FIM ) scores improved from admission to discharge for patients with GBM, brain metastases and other tumours. Estimated median survival was 141 days for brain metastases, 214 days for GBM and 439 days for other tumours. Low admission dexamethasone dose and high FIM gain predicted better survival in GBM. For brain metastases, high FIM gain, low dexamethasone dose and no organ metastases were positive prognostic factors. CONCLUSIONS: Patients with primary and metastatic brain tumours achieved functional gains after rehabilitation. High functional improvement is a significant predictor of longer survival in brain metastases and GBM. This study has implications for rehabilitation in the post-acute management of patients who have disabilities due to brain tumours.

Using arteriovenous fistulae as a dual access for hemodialysis and total parenteral nutrition administration is feasible with a good outcome: a case series.

End stage renal failure patients requiring long term total parenteral nutrition (TPN) often have multiple central line placements due to line infection or occlusion. Sometimes this can cause central venous stenosis or even occlusion. We present three cases in this consecutive series, in which we have successfully used arteriovenous fistulae for both hemodialysis and long term TPN administration as an alternative route without any complications. We therefore think that native AVF and grafts can be used as dual access for hemodialysis and TPN administration provided careful case selection, counselling and follow-up.

Cutaneous manifestations of tuberculosis.

Cutaneous involvement is a rare manifestation of tuberculosis (TB). The correct diagnosis is often significantly delayed because cutaneous TB is not routinely considered in the differential diagnosis or because investigations fail to reveal the presence of Mycobacterium tuberculosis. The clinical features of cutaneous TB are diverse, and result from exogenous and endogenous spread of M. tuberculosis and from immune-mediated mechanisms. The recognition of cutaneous TB is important, as the diagnosis is frequently overlooked resulting in delayed treatment.

Prognostic indicators in metastatic spinal cord compression: using functional independence measure and Tokuhashi scale to optimize rehabilitation planning.

STUDY DESIGN: Retrospective, descriptive study. OBJECTIVE: To determine if patients with metastatic spinal cord compression (MSCC) make significant functional gains through rehabilitation. To study survival and predictors of survival in MSCC. To explore predictive factors for high or low functional gains in MSCC. SETTING: Inpatient neuro-oncology rehabilitation ward, Henderson General Hospital, Hamilton, Canada. METHODS: Clinical records were examined for 63 inpatients with MSCC. Demographics, treatment of MSCC, length of rehabilitation, admission, and discharge Functional Independence Measure (FIM) scores, Tokuhashi score and survival data were collected. Statistical analyses included nonparametric comparisons, Kaplan-Meier analyses, Cox regression, and exploratory logistic regression. RESULTS: FIM score improved from 83 to 102 (P<0.0001). Estimated median survival from time of rehabilitation was 10.0 months. Kaplan-Meier analysis showed longer survival in patients with high Tokuhashi scores (9-15) compared to low scores (0-8) (P<0.005); and high FIM change (>13) compared to low FIM change (< or =13) (P<0.02). Cox regression revealed that high FIM gain and high Tokuhashi score were prognostic factors. Logistic regression showed Tokuhashi score (odds ratio (OR)=1.30, 95% confidence interval (CI)=1.04-1.62) and length of rehabilitation (OR=1.04, 95% confidence interval (CI)=1.01-1.07) were associated with high FIM gain. CONCLUSIONS: Rehabilitation improves functional outcomes in MSCC. Patients who had a high Tokuhashi score and achieved high functional gains after rehabilitation had longer survival. Tokuhashi score and length of rehabilitation were associated with high FIM gain. The Tokuhashi score can help identify patients with good prognosis and potential for improvement during rehabilitation.

Neutron production from feedback controlled thermal cycling of a pyroelectric crystal.

The LLNL Crystal Driven Neutron Source is operational and has produced record ion currents of approximately 10 nA and neutron output of 1.9(+/-0.3)x10(5) per thermal cycle using a crystal heating rate of 0.2 degrees C/s from 10 to 110 degrees C. A 3 cm diameter by 1 cm thick LiTaO(3) crystal with a socket secured field emitter tip is thermally cycled with feedback control for ionization and acceleration of deuterons onto a deuterated target to produce D-D fusion neutrons. The entire crystal and temperature system is mounted on a bellows which allows movement of the crystal along the beam axis and is completely contained on a single small vacuum flange. The modular crystal assembly permitted experimental flexibility. Operationally, flashover breakdowns along the side of the crystal and poor emitter tip characteristics can limit the neutron source. The experimental neutron results extend earlier published work by increasing the ion current and pulse length significantly to achieve a factor-of-two higher neutron output per thermal cycle. These findings are reviewed along with details of the instrument.

An evaluation of a rapid urine test for the diagnosis of Helicobacter pylori infection in the Chinese population.

BACKGROUND: A new rapid urine test was developed to detect anti-Helicobacter pylori antibody in urine using the principle of immunochromatography. The accuracy of this test in the Chinese population remains to be defined. AIM: To evaluate a new rapid urine test for the diagnosis of H. pylori infection in the Chinese population. METHODS: Eligible patients without previous treatment of H. pylori were recruited. In-house rapid urease test and histology were used as the gold standard. The rapid urine test (RAPIRUN H. pylori antibody) was performed and the results were compared with the gold standard. RESULTS: One hundred and twenty-three patients were eligible for analysis and 61 (50%) were H. pylori positive by the gold standard. The rapid urine test showed a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 96.7%, 95.2%, 95.2%, 96.7% and 95.9%, respectively. Results were obtained within 20 min and no special laboratory support was required. CONCLUSIONS: The rapid urine test by immunochromatography is highly accurate for the diagnosis of H. pylori infection in untreated Chinese patients.

Optimal serological tests for the detection of Helicobacter pylori infection in the Chinese population.

BACKGROUND: Numerous serological tests for the detection of Helicobacter pylori infection have been developed. However, many perform poorly when evaluated in the Chinese population. AIM: To search for optimal serological tests for the detection of H. pylori infection in Chinese patients. METHODS: Consecutive dyspeptic patients referred for upper endoscopy were recruited. During endoscopy, gastric biopsies were taken for the CLOtest and histological examination. Patients were then given a 13C-urea breath test. Sera were used to test for H. pylori infection, employing three commercial enzyme-linked immunosorbent assay kits (pylori DTect, HP IgG and GAP IgG). Results were compared with the gold standard defined by the CLOtest, histology and 13C-urea breath test. RESULTS: Among the 142 patients (47 male, 95 female; mean age, 49 years) recruited, 81 (57%) were H. pylori-positive, 57 (40%) were H. pylori-negative and four (3%) were defined to be indeterminate. Using a self-defined cut-off value after calculation, the best accuracies for the pylori DTect, HP IgG and GAP IgG tests were 97%, 91% and 80%, respectively. CONCLUSIONS: The pylori DTect test is an optimal serological test for the detection of H. pylori infection in Hong Kong Chinese patients. The HP IgG test may be used as an alternative.