Measurement of Dark Ice-Ablator Mix in Inertial Confinement Fusion.

We present measurements of ice-ablator mix at stagnation of inertially confined, cryogenically layered capsule implosions. An ice layer thickness scan with layers significantly thinner than used in ignition experiments enables us to investigate mix near the inner ablator interface. Our experiments reveal for the first time that the majority of atomically mixed ablator material is "dark" mix. It is seeded by the ice-ablator interface instability and located in the relatively cooler, denser region of the fuel assembly surrounding the fusion hot spot. The amount of dark mix is an important quantity as it is thought to affect both fusion fuel compression and burn propagation when it turns into hot mix as the burn wave propagates through the initially colder fuel region surrounding an igniting hot spot. We demonstrate a significant reduction in ice-ablator mix in the hot-spot boundary region when we increase the initial ice layer thickness.

Exploring approaches to dietetic assessment of a common task across different universities through assessment moderation.

BACKGROUND: Assessment presents one of the greatest challenges to evaluating health professional trainee performance, as a result of the subjectivity of judgements and variability in assessor standards. The present study aimed to test a moderation procedure for assessment across four independent universities and explore approaches to assessment and the factors that influence assessment decisions. METHODS: Assessment tasks designed independently by each of the four universities to assess student readiness for placement were chosen for the present study. Each university provided four student performance recordings for moderation. Eight different academic assessors viewed the student performances and assessed them using the corresponding university assessment instrument. Assessment results were collated and presented back to the assessors, together with the original university assessment results. Results were discussed with assessors to explore variations. The discussion was recorded, transcribed, thematically analysed and presented back to all assessors to achieve consensus on the emerging major learnings. RESULTS: Although there were differences in absolute scores, there was consistency (12 out of 16 performances) in overall judgement decisions regarding placement readiness. Proficient communication skills were considered a key factor when determining placement readiness. The discussion revealed: (i) assessment instruments; (ii) assessor factors; and (iii) the subjectivity of judgement as the major factors influencing assessment. CONCLUSIONS: Assessment moderation is a useful method for improving the quality of assessment decisions by sharing understanding and aligning standards of performance.

Dynamics and universal scaling law in geometrically-controlled sessile drop evaporation.

The evaporation of a liquid drop on a solid substrate is a remarkably common phenomenon. Yet, the complexity of the underlying mechanisms has constrained previous studies to spherically symmetric configurations. Here we investigate well-defined, non-spherical evaporating drops of pure liquids and binary mixtures. We deduce a universal scaling law for the evaporation rate valid for any shape and demonstrate that more curved regions lead to preferential localized depositions in particle-laden drops. Furthermore, geometry induces well-defined flow structures within the drop that change according to the driving mechanism. In the case of binary mixtures, geometry dictates the spatial segregation of the more volatile component as it is depleted. Our results suggest that the drop geometry can be exploited to prescribe the particle deposition and evaporative dynamics of pure drops and the mixing characteristics of multicomponent drops, which may be of interest to a wide range of industrial and scientific applications.

Dural infantile hemangioma masquerading as a skull vault lesion.

We describe a case of intracranial dural IH initially diagnosed as a primary skull vault lesion hemangioma due to associated focal hyperostosis. Histopathologic examination of the dural component confirmed IH. The case is discussed in the context of IH within the neural axis.

Prenatal diagnosis of supernumerary ring chromosome 1: case report and review of the literature.

A supernumerary ring chromosome was found on amniocentesis performed for advanced maternal age. A review of the literature found 34 reports of supernumerary ring chromosome I which are compared to our case.

Patient decisions regarding prenatal aneuploid fluorescence in situ hybridization results.

OBJECTIVE: To determine an appropriate risk cut-off to offer prenatal aneuploid FISH, and if FISH results affect patient decisions regarding pregnancy management. METHOD: Retrospective evaluation of 707 patients presenting for diagnostic prenatal testing. Studied parameters included gestational age, indication for testing, aneuploid risk, procedure performed, FISH (whether offered, requested, and/or performed), result turn-around time, karyotype results, decision after obtaining results, and the timing of that decision. Patients who were offered FISH were compared to those not offered FISH (student T-test). RESULTS: Twenty-five clinically significant abnormalities were detected by karyotype and/or FISH analysis. Thirteen out of 17 patients electing pregnancy interruption had FISH performed. There were no differences between the group that interrupted following FISH (n=7) and the group that interrupted following final karyotype results (n=6). Turn-around times for those abnormal samples with FISH testing was significantly shorter than for those without FISH testing (p=0.02). Risk thresholds of >or=0.5%, >or=1%, >or=2%, or >or=3%, would detect 92%, 84%, 48%, and 32% of the clinically significant anomalies with 663, 317, 118, and 66 FISH analyses performed, respectively. CONCLUSION: Acting on FISH results alone afforded a significantly shorter interval between test and pregnancy interruption. A risk cut-off >or=1% appears to optimize the detection rate and the yield of abnormal results.

Failure of aneurysm sac shrinkage after endovascular repair; the effect of mural calcification.

AIM: To evaluate the effect of abdominal aortic aneurysm wall calcification on subsequent sac shrinkage after endovascular repair. MATERIALS AND METHODS: Seventy-three patients underwent endovascular aneurysm repair. The degree of sac wall calcification on pre-procedural computed tomography (CT) examination was graded from 1 to 4 according to the degree of circumferential involvement. On follow-up CT imaging, the maximum transverse diameter (MTD) of the sac was recorded, as well as the presence or absence of endoleak. In those patients with a non-shrinking aneurysm, but no CT evidence of endoleak, contrast-enhanced ultrasound (USS) was performed. Any patient with an endoleak, however diagnosed, was excluded from the study. Kruskal-Wallis and Spearman's rank correlation coefficient testing was applied to compare the degree of calcification and change in MTD. RESULTS: Sixty-three pre-procedural CT images were available for calcification grading. Six of this group had endoleaks resulting in 57 sets of data being available for the study. A reduction in MTD occurred in 68.25% of these patients by 1 year post-procedure. Our figures show aortic calcification is inversely associated with MTD reduction at 6 months (p = 0.01), 1 year (p = 0.05) and 2 years (p = 0.05). CONCLUSION: This study indicates that the degree of aortic wall calcification is significant in predicting MTD reduction post-endovascular repair. The possible mechanisms and implications of this are discussed.

Natural history of posterior iliac crest bone graft donation for spinal surgery: a prospective analysis of morbidity.

STUDY DESIGN: A prospective study was conducted to examine bone graft donor site morbidity in 106 consecutive patients undergoing posterior spinal fusion. OBJECTIVES: To perform a prospective analysis of donor site morbidity, to document the incidence of major complications, and to collect information on the impact of autologous bone graft harvesting from the posterior iliac crest on the overall outcome of spinal surgery. SUMMARY OF BACKGROUND: Bone graft harvesting from the posterior iliac crest for spinal fusion is a source of significant morbidity. Previous retrospective case studies indicate that minor complications are common, but they do not define the natural history and complications of posterior iliac crest bone graft harvesting. METHODS: A standardized harvesting technique was used. At 3, 6, and 12 months after surgery, the patients completed a proforma questionnaire rating symptoms on a visual analog scale and underwent a postoperative examination by the surgeon. Finally, overall surgical outcome was assessed at 12 months. RESULTS: The major component of morbidity is donor site pain. Mean pain scores were 1.640 at 3 months, 1.812 at 6 months, and 1.207 at 12 months. The pain at 12 months was significantly less than at 3 and 6 months (P = 0.005), with a trend toward the highest scores at 6 months. A pain score of 0 was reported by 55% of the patients. Local sensory loss was found in 10% of the patients. Outcome assessment showed significant differences in morbidity for surgery performed at different spinal levels (P = 0.001), with lumbosacral surgery resulting in worse outcomes than either cervical (P < 0.05) or thoracolumbar (P < 0.05) surgery. Significantly higher visual analog scores were observed at 6 months in patients with poorer overall outcomes. CONCLUSIONS: According to this study, it is reasonable to reassure patients that a good result from spinal surgery will not be compromised by severe symptoms or major morbidity secondary to posterior iliac crest bone graft donation. Before surgery, patients may be advised concerning the risks of donor site pain, which improves significantly by 12 months, local tenderness, and uncommonly localized sensory loss.

Stereotactic breast biopsy of nonpalpable lesions: determinants of ductal carcinoma in situ underestimation rates.

PURPOSE: To measure the effect of biopsy device, probe size, mammographic lesion type, lesion size, and number of samples obtained per lesion on the ductal carcinoma in situ (DCIS) underestimation rate. MATERIALS AND METHODS: Nonpalpable breast lesions at 16 institutions received a histologic diagnosis of DCIS after 14-gauge automated large-core biopsy in 373 lesions and after 14- or 11-gauge directional vacuum-assisted biopsy in 953 lesions. The presence of histopathologic invasive carcinoma was noted at subsequent surgical biopsy. RESULTS: By performing the chi(2) test, independent significant DCIS underestimation rates by biopsy device were 20.4% (76 of 373) of lesions diagnosed at large-core biopsy and 11.2% (107 of 953) of lesions diagnosed at vacuum-assisted biopsy (P <.001); by lesion type, 24.3% (35 of 144) of masses and 12.5% (148 of 1,182) of microcalcifications (P <.001); and by number of specimens per lesion, 17.5% (88 of 502) with 10 or fewer specimens and 11.5% (92 of 799) with greater than 10 (P <.02). DCIS underestimations increased with lesion size. CONCLUSION: DCIS underestimations were 1.9 times more frequent with masses than with calcifications, 1.8 times more frequent with large-core biopsy than with vacuum-assisted biopsy, and 1.5 times more frequent with 10 or fewer specimens per lesion than with more than 10 specimens per lesion.

99Tcm-HMPAO leucocyte labelling in orofacial granulomatosis and gastrointestinal Crohn's disease in childhood and early adulthood.

Orofacial granulomatosis is a granulomatous inflammatory disorder, affecting the soft tissues of the face and mouth. The predominant feature is disfiguring lip swelling. Patients with this condition may be exhibiting a Type IV hypersensitivity reaction to dietary or environmental allergens, or these may be the orofacial manifestations of underlying gastrointestinal Crohn's disease. The results of 99Tcm-HMPAO leucocyte labelling of the gastrointestinal tract in 14 patients with orofacial granulomatosis and 15 patients with known gastrointestinal Crohn's disease are presented, indicating that this is a useful and non-invasive screening test for the identification of gastrointestinal Crohn's disease in paediatric and young adult patients presenting with orofacial granulomatosis.

Clinical profiles of four large pedigrees with familial dilated cardiomyopathy: preliminary recommendations for clinical practice.

OBJECTIVES: This study aimed to characterize the clinical profile of familial dilated cardiomyopathy (FDC) in the families of four index patients initially diagnosed with idiopathic dilated cardiomyopathy (IDC) and to provide clinical practice recommendations for physicians dealing with these diseases. BACKGROUND: Recent evidence indicates that approximately one-half of patients diagnosed with IDC will have FDC, a genetically transmissible disease, but the clinical profile of families screened for FDC in the U.S. has not been well documented. Additionally, recent ethical guidelines suggest increased responsibilities in caring for patients with newly found genetic cardiovascular disease. METHODS: After identification of four families with FDC, we undertook clinical screening including medical history, physical examination, electrocardiogram and echocardiogram. Diagnostic criteria for FDC-affected status of asymptomatic family members was based on left ventricular enlargement (LVE). Subjects with confounding cardiovascular diagnoses or body mass indices >35 were excluded. RESULTS: We identified 798 living members from the four FDC pedigrees, and screened 216 adults and 129 children (age <16 years). Twenty percent of family members were found to be affected with FDC; 82.8% of those affected were asymptomatic. All four pedigrees demonstrated autosomal dominant patterns of inheritance. The average left ventricular end-diastolic dimension was 61.4 mm for affected and 48.4 mm for unaffected subjects, with an average age of 38.3 years (+/- 14.6 years) for affected and 32.1 years for unaffected subjects. The age of onset for FDC varied considerably between and within families. Presenting symptoms when present were decompensated heart failure or sudden death. CONCLUSIONS: We propose that with a new diagnosis of IDC, a thorough family history for FDC should be obtained, followed by echocardiographic-based screening of first-degree relatives for LVE, assuming their voluntary participation. If a diagnosis of FDC is established, we suggest further screening of first-degree relatives, and all subjects with FDC undergo medical treatment following established guidelines. Counseling of family members should emphasize the heritable nature of the disease, the age-dependent penetrance and the unpredictable clinical course.

SPECT imaging of odor identification in schizophrenia.

Deficits in olfactory identification, despite normal odor perception, are found in some neuropsychiatric disorders, including schizophrenia. We examined if regional cerebral blood flow (rCBF) differed between schizophrenia patients and controls during odor identification, hypothesizing that these brain regions could be relevant to odor identification impairments. Eight schizophrenia and eight comparison subjects provided a baseline (picture identity matching) and activation (odor identification) SPECT scan, obtained using 99mTc-HMPAO in a low dose/high dose design. Six patients and seven controls had analyzable data. MEDX data saved in ANALYZE format for SPM 95 generated paired t-test statistical data for display in Talairach space, with rCBF changes given as Z-scores. There was no schizophrenia vs. control group difference in rCBF for the baseline picture-matching test. For odor identification, schizophrenia patients had a hypometabolic right-sided cortical region that included the frontal lobe Broca's area, superior temporal lobe, and supramarginal and angular gyri. Post hoc within-group contrasts of picture-matching vs. odor identification showed that the controls significantly increased rCBF in the right-sided inferior temporal fusiform gyrus, and bilateral hippocampi and visual association areas for the odor test. The schizophrenia group showed no rCBF differences for picture-matching compared to odor identification. Patients showed significant hypometabolism in right-sided cortical areas for odor identification. They also failed to show increased rCBF in the hippocampus and visual association area, as seen in controls for odor identification compared to picture-matching. These regions may be unique to schizophrenia or have broader implications for olfactory memory retrieval.

Atypical ductal hyperplasia diagnosed at stereotactic breast biopsy: improved reliability with 14-gauge, directional, vacuum-assisted biopsy.

PURPOSE: To compare histologic findings of atypical ductal hyperplasia (ADH) at 14-gauge, directional, vacuum-assisted breast biopsy (hereafter, vacuum-assisted biopsy) and at 14-gauge, automated, large-core breast biopsy (hereafter, large-core biopsy) with findings at histologic examination after surgical biopsy. MATERIALS AND METHODS: Nonpalpable breast lesions were diagnosed as ADH at histologic examination after vacuum-assisted biopsy in 88 lesions in seven institutions and after large-core biopsy in 55 previously reported lesions. Histologic findings at subsequent surgical biopsy were compared for the presence of carcinoma. RESULTS: On the basis of histologic findings of carcinoma at surgical biopsy, the diagnosis of ADH was not correct in 26 (48%) of 54 lesions sampled at large-core biopsy and in 13 (18%) of 74 lesions sampled at vacuum-assisted biopsy (Fisher exact test, P < .0004). More tissue specimens were obtained at vacuum-assisted biopsy (mean, 15.8 specimens) than at large-core biopsy (mean, 9.7 specimens). Individual specimens were twice as large at vacuum-assisted biopsy (mean, 34 mg) as at large-core biopsy (mean, 17 mg) (previously reported). CONCLUSION: ADH was diagnosed 2.7 times more reliably at vacuum-assisted biopsy than at large-core biopsy (with no increase in complications) with most of the improvement as a result of acquisition of more than 10 specimens per lesion, but carcinoma was sufficiently underestimated with both methods to necessitate surgical biopsy.

An investigation into the use of SDS-PAGE of cell surface extracts and proteolytic activity to differentiate Prevotella nigrescens and Prevotella intermedia.

By comparison of the cell surface proteins derived from the outer membrane and fibrils from 14 Prevotella intermedia and 19 Prevotella nigrescens strains using SDS and analysed by SDS-PAGE, it was possible to distinguish the two species. A polypeptide of approx. 21 kDa distinguished P. intermedia strains, whereas two polypeptides of approx. 18 and 22 kDa could be used to identify P. nigrescens strains. Four other human oral black pigmented bacterial species (Porphyromonas gingivalis, Prevotella denticola, Prevotella loescheii and Prevotella melaninogenica) did not have the 18-, 21- or 22-kDa polypeptides shown by P. intermedia or P. nigrescens. The cell-associated proteolytic activity of eight strains of P. intermedia, 14 strains of P. nigrescens and one strain of P. gingivalis (W50) was assessed using four chromogenic substrates. The hydrolysis of the substrate GPPNA (indicative of dipeptidyl peptidase IV-like activity) and SAAPPNA (elastase-like activity) by P. intermedia strains varied from 32 to 114 units and 0.5 to 12.6 units of activity respectively, where one unit was defined as the amount of protease enzyme catalysing the formation of 1 nmol of p-nitroaniline under experimental conditions. 37.5% (3 of 8) of P. intermedia strains hydrolysed SAAPPNA (chymotrypsin-like enzyme activity) with activities of between 7 and 12 units. The hydrolysis of GPPNA and SAAAPNA by P. nigrescens strains was 32-149 and 3-16 units, respectively. 57% (8 of 14) of P. nigrescens strains hydrolysed SAAPPPNA with activities ranging from 3 to 8 units. None of the P. intermedia or P. nigrescens strains examined were found to have trypsin-like enzyme activity (BAPNA hydrolysis). The GPPNA and SAAAPNA hydrolytic activity associated with the proteases from Porphyromonas gingivalis W50 was at least twice that of P. intermedia and P. nigrescens strains. The similar peptidase activities of P. intermedia and P. nigrescens against chromogenic substrates cannot be used to differentiate the species, but SDS-PAGE of cell surface protein extracts allowed unambiguous speciation between P. intermedia and P. nigrescens. This simple technique of cell surface protein analysis can be performed in most laboratories and offers a convenient way by which to differentiate the two species.

Odor discrimination deficits in schizophrenia: association with eye movement dysfunction.

Odor discrimination deficits were found in 80% of 20 schizophrenia patients and in none of the 20 age- and sex-matched comparison subjects. Olfactory discrimination was reliably measured in the patients. Twelve patients in this study also had smooth pursuit eye movement (SPEM) qualitatively recorded. The olfactory discrimination scores were highly correlated to SPEM but not to other clinical measures. This correlation suggests a shared neurobiology, possibly involving working memory.