Lunar surface engineering properties experiment definition. Volume 1: Mechanics, properties, and stabilization of lunar soils

Lunar soil simulation and stabilization, and impact penetrometer studie

Chondrocyte death after drilling and articular screw insertion in a bovine model

SummaryObjectiveIntra-articular screws are used for internal fixation of osteochondral fragments after fracture or osteochondritis dissecans. This causes cartilage injury potentially leading to chondrocyte death. We have visualised/quantified the hole and zone of cell death (ZCD) in cartilage after drilling/insertion of various articular screws.MethodUsing an ex vivo bovine model with transmitted light and confocal laser scanning microscopy (CLSM), the holes and ZCD following drilling/insertion of articular screws (cortical screw, headless variable pitch metallic screw, headless variable pitch bioabsorbable screw) were evaluated. In situ chondrocyte death was determined by live/dead cell viability assay. An imaging/quantification protocol was developed to compare hole diameter and ZCD from drilling/insertion of screws into cartilage. The effect of saline irrigation during drilling on the ZCD was also quantified.ResultsScrew insertion created holes in cartilage that were significantly (P ≤ 0.001) less than the diameters of the equipment used. With a 1.5 mm drill, a ZCD of 580.2 ± 124 μm was produced which increased to 637.0 ± 44 μm following insertion of a 2 mm cortical screw although this was not significant (P > 0.05). The ZCD from insertion of the variable pitch headless screws (diam. 3.5 mm) was lower for the metallic compared to the bioabsorbable design (800.9 ± 159 vs 1,236.4 ± 212 μm, respectively; P < 0.01). The ZCD from drilling was reduced ∼50% (P < 0.001) by saline irrigation.ConclusionsCartilage injury during intra-articular screw fixation caused a ZCD around the hole irrespective of screw design. Saline irrigation significantly reduced the ZCD from drilling into cartilage

Outbreak of Aeromonas hydrophila wound infections association with mud football

On 16 February 2002, a total of 26 people presented to the emergency department of the local hospital in the rural town of Collie in southwest Western Australia with many infected scratches and pustules distributed over their bodies. All of the patients had participated in a “mud football” competition the previous day, in which there had been 100 participants. One patient required removal of an infected thumbnail, and another required surgical debridement of an infected toe. Aeromonas hydrophila was isolated from all 3 patients from whom swab specimens were obtained. To prepare the mud football fields, a paddock was irrigated with water that was pumped from an adjacent river during the 1-month period before the competition. A. hydrophila was subsequently isolated from a water sample obtained from the river. This is the first published report of an outbreak of A. hydrophila wound infections associated with exposure to mud.Hassan Vally, Amanda Whittle, Scott Cameron, Gary K. Dowse and Tony Watso

Influence of Context on Item Parameters in Forced-Choice Personality Assessments

A fundamental assumption in computerized adaptive testing (CAT) is that item parameters are invariant with respect to context – items surrounding the administered item. This assumption, however, may not hold in forced-choice (FC) assessments, where explicit comparisons are made between items included in the same block. We empirically examined the influence of context on item parameters by comparing parameter estimates from two FC instruments. The first instrument was compiled of blocks of three items, whereas in the second, the context was manipulated by adding one item to each block, resulting in blocks of four. The item parameter estimates were highly similar. However, a small number of significant deviations were observed, confirming the importance of context when designing adaptive FC assessments. Two patterns of such deviations were identified, and methods to reduce their occurrences in a FC CAT setting were proposed. It was shown that with a small proportion of violations of the parameter invariance assumption, score estimation remained stable

Symptoms predicting remission after divalproex augmentation with olanzapine in partially nonresponsive patients experiencing mixed bipolar I episode: a post-hoc analysis of a randomized controlled study

<p>Abstract</p> <p>Background</p> <p>Rating scale items in a 6-week clinical trial of olanzapine versus placebo augmentation in patients with mixed bipolar disorder partially nonresponsive to ≥14 days of divalproex monotherapy were analyzed to characterize symptom patterns that could predict remission. At baseline, the two treatment groups were similar.</p> <p>Findings</p> <p>Factor analysis with Varimax rotation was performed <it>post hoc </it>on baseline items of the 21-Item Hamilton Depression Rating Scale (HDRS-21) and Young Mania Rating Scale (YMRS). Backwards-elimination logistic regression ascertained factors predictive of protocol-defined endpoint remission (HDRS-21 score ≤ 8 and YMRS score ≤ 12) with subsequent determination of optimally predictive factor score cutoffs.</p> <p>Factors for Psychomotor activity (YMRS items for elevated mood, increased motor activity, and increased speech and HDRS-21 agitation item) and Guilt/Suicidality (HDRS-21 items for guilt and suicidality) significantly predicted endpoint remission in the divalproex+olanzapine group. No factor predicted remission in the divalproex+placebo group. Patients in the divalproex+olanzapine group with high pre-augmentation psychomotor activity (scores ≥10) were more likely to remit compared to those with lower psychomotor activity (odds ratio [OR] = 3.09, 95% confidence interval [CI] = 1.22-7.79), and patients with marginally high Guilt/Suicidality (scores ≥2) were less likely to remit than those with lower scores (OR = 0.37, 95% CI = 0.13-1.03). Remission rates for divalproex+placebo vs. divalproex+olanzapine patients with high psychomotor activity scores were 22% vs. 45% (p = 0.08) and 33% vs. 48% (p = 0.29) for patients with low Guilt/Suicidality scores.</p> <p>Conclusions</p> <p>Patients who were partially nonresponsive to divalproex treatment with remaining high vs. low psychomotor activity levels or minimal vs. greater guilt/suicidality symptoms were more likely to remit with olanzapine augmentation.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov; <url>http://clinicaltrials.gov/ct2/show/NCT00402324?term=NCT00402324&rank=1</url>, Identifier: NCT00402324</p

MgB2 superconducting thin films with a transition temperature of 39 Kelvin

We report the growth of high-quality c-axis-oriented epitaxial MgB2 thin films by using a pulsed laser deposition technique. The thin films grown on (1`1 0 2) Al2O3 substrates show a Tc of 39 K. The critical current density in zero field is ~ 6 x 10^6 A/cm2 at 5 K and ~ 3 x 10^5 A/cm^2 at 35 K, suggesting that this compound has great potential for electronic device applications, such as microwave devices and superconducting quantum interference devices. For the films deposited on Al2O3, X-ray diffraction patterns indicate a highly c-axis-oriented crystal structure perpendicular to the substrate surface.Comment: 3 pages and 3 figure

Mediation of smoking-associated postoperative mortality by perioperative complications in veterans undergoing elective surgery: data from Veterans Affairs Surgical Quality Improvement Program (VASQIP)--a cohort study

OBJECTIVE: To assess the mediation of smoking-associated postoperative mortality by postoperative complications. DESIGN: Observational cohort study. SETTING: Using data from the Veterans Affairs (VA) Surgical Quality Improvement Programme, a quality assurance programme for major surgical procedures in the VA healthcare system, we assessed the association of current smoking at the time of the surgery with 6-month and 1-year mortality. PRIMARY AND SECONDARY OUTCOME MEASURES: Using mediation analyses, we calculated the relative contribution of each smoking-associated complication to smoking-associated postoperative mortality, both unadjusted and adjusted for age, race/ethnicity, work relative value unit of the operation, surgeon specialty, American Society of Anesthesiologists class and year of surgery. Smoking-associated complications included surgical site infection (SSI), cardiovascular complications (myocardial infarction, cardiac arrest and/or stroke) and pulmonary complications (pneumonia, failure to wean and/or reintubation). RESULTS: There were 186 632 never smokers and 135 741 current smokers. The association of smoking and mortality was mediated by smoking-related complications with varying effects. In unadjusted analyses, the proportions of mediation of smoking to 6-month mortality explained by the complications were as follows: SSIs 22%, cardiovascular complications 12% and pulmonary complications 89%. In adjusted analyses, the per cents mediated by each complication were as follows: SSIs 2%, cardiovascular complications 4% and pulmonary complications 22%. In adjusted analyses for 1-year mortality, respective per cents mediated were 2%, 3% and 16%. CONCLUSIONS: Pulmonary complications, followed by cardiovascular complications and SSIs were mediators of smoking-associated 6-month and 1-year mortality. Interventions targeting smoking cessation and prevention and early treatment of pulmonary complications has the likelihood of reducing postoperative mortality after elective surgery

Parallel Vector Lock-In Thermal Wave IR Video Imaging of Microcracks in Cu Foils Deposited on Polyimide

Recently, the concept of area-wide lock-in detection in infrared video imaging and its application to thermal wave imaging was demonstrated.[1] This technique combines the lock-in detection method with an IR video camera and almost real-time digital image processing to form a parallel vector lock-in thermal wave IR video imaging system. In this method each pixel of an image is processed in the manner similar to the lock-in detection method while the sample is excited (heated) synchronously with a square-wave modulated joule heating. The synchronous detection allows the non-synchronous background radiation to be subtracted from the signal resulting in an enhanced signal-to-noise ratio, thus allowing the signal of interest to be measured even in situations where it is completely masked by noise. The advantage of IR detection (8–12 µm) and high speed data acquisition combined with the area-wide lock-in detection makes this a unique thermal wave imaging technique for non-destructive evaluation. In this paper we report the application of this lock-in thermal wave IR video imaging technique using ac Joule heating to the imaging of microcracks in Cu foils deposited on polyimide substrates. Comparison of the lock-in video images of good and faulty samples are presented

New axially symmetric Yang-Mills-Higgs solutions with negative cosmological constant

We construct numerically new axially symmetric solutions of SU(2) Yang-Mills-Higgs theory in $(3+1)$ anti-de Sitter spacetime. Two types of finite energy, regular configurations are considered: multimonopole solutions with magnetic charge $n>1$ and monopole-antimonopole pairs with zero net magnetic charge. A somewhat detailed analysis of the boundary conditions for axially symmetric solutions is presented. The properties of these solutions are investigated, with a view to compare with those on a flat spacetime background. The basic properties of the gravitating generalizations of these configurations are also discussed.Comment: 18 pages, 7 figures; v2: typos correcte