171 research outputs found

    Analysis of Lunar Surface Charging for a Candidate Spacecraft Using NASCAP-2K

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    The characterization of the electromagnetic interaction for a spacecraft in the lunar environment, and identification of viable charging mitigation strategies, is a critical lunar mission design task, as spacecraft charging has important implications both for science applications and for astronaut safety. To that end, we have performed surface charging calculations of a candidate lunar spacecraft for lunar orbiting and lunar landing missions. We construct a model of the spacecraft with candidate materials having appropriate electrical properties using Object Toolkit and perform the spacecraft charging analysis using Nascap-2k, the NASA/AFRL sponsored spacecraft charging analysis tool. We use nominal and atypical lunar environments appropriate for lunar orbiting and lunar landing missions to establish current collection of lunar ions and electrons. In addition, we include a geostationary orbit case to demonstrate a bounding example of extreme (negative) charging of a lunar spacecraft in the geostationary orbit environment. Results from the charging analysis demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as expected. We compare charging results to data taken during previous lunar orbiting or lunar flyby spacecraft missions

    Can Urethral Retroresistance Pressures Predict Midurethral Sling Outcomes?

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    OBJECTIVE: To determine whether preoperative urethral resistance pressure (URP) measurements could predict success or failure of a tension-free vaginal tape (TVT) sling. METHODS: Subjects came from a previously published study comparing URP measurements to a validated urinary incontinence symptom survey (UISS). We contacted patients from that study to determine whether they had subsequently undergone TVT surgery. Within that cohort, we determined the “current” (i.e., postoperative) UISS and Sandvik urinary incontinence severity score. Success of a TVT sling in this group was defined in 4 ways: (1) postoperative UISS score \u3c 3, (2) postoperative UISS score \u3c 75% of the preoperative score, (3) postoperative Sandvik score \u3c 6, and (4) postoperative Sandvik score \u3c 2. These definitions of “success” were compared across demographic and treatment variables using the Student’s t test, ANOVA, χ 2 and ROC curves. RESULTS: We contacted 69 women who had in fact received a TVT sling after their participation in the previously published study mentioned above. Among these 69 women, mean preoperative urethral retroresistance pressure values were not predictive of surgical success. CONCLUSION: Preoperative urethral retroresistance pressure measurements did not reliably predict surgical success or failure; therefore, this urodynamic test is of little value to the clinician

    Evaluation of Bulk Charging in Geostationary Transfer Orbit and Earth Escape Trajectories Using the Numit 1-D Charging Model

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    The NUMIT 1-dimensional bulk charging model is used as a screening to ol for evaluating time-dependent bulk internal or deep dielectric) ch arging of dielectrics exposed to penetrating electron environments. T he code is modified to accept time dependent electron flux time serie s along satellite orbits for the electron environment inputs instead of using the static electron flux environment input originally used b y the code and widely adopted in bulk charging models. Application of the screening technique ts demonstrated for three cases of spacecraf t exposure within the Earth's radiation belts including a geostationa ry transfer orbit and an Earth-Moon transit trajectory for a range of orbit inclinations. Electric fields and charge densities are compute d for dielectric materials with varying electrical properties exposed to relativistic electron environments along the orbits. Our objectiv e is to demonstrate a preliminary application of the time-dependent e nvironments input to the NUMIT code for evaluating charging risks to exposed dielectrics used on spacecraft when exposed to the Earth's ra diation belts. The results demonstrate that the NUMIT electric field values in GTO orbits with multiple encounters with the Earth's radiat ion belts are consistent with previous studies of charging in GTO orb its and that potential threat conditions for electrostatic discharge exist on lunar transit trajectories depending on the electrical proper ties of the materials exposed to the radiation environment

    Glembatumumab vedotin for patients with metastatic, gpNMB overexpressing, triple-negative breast cancer (“METRIC”): a randomized multicenter study

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    Breast cancer; CancerCàncer de mama; CàncerCáncer de mama; CáncerThe METRIC study (NCT#0199733) explored a novel antibody–drug conjugate, glembatumumab vedotin (GV), targeting gpNMB that is overexpressed in ~40% of patients with triple-negative breast cancer (TNBC) and associated with poor prognosis. The study was a randomized, open-label, phase 2b study that evaluated progression-free survival (PFS) of GV compared with capecitabine in gpNMB-overexpressing TNBC. Patients who had previously received anthracycline and taxane-based therapy were randomized 2:1 to receive, GV (1.88 mg/kg IV q21 days) or capecitabine (2500 mg/m2 PO daily d1–14 q21 days). The primary endpoint was RECIST 1.1 PFS per independent, blinded central review. In all, 327 patients were randomized to GV (213 treated) or capecitabine (92 treated). Median PFS was 2.9 months for GV vs. 2.8 months for capecitabine. The most common grade ≥3 toxicities for GV were neutropenia, rash, and leukopenia, and for capecitabine were fatigue, diarrhea, and palmar-plantar erythrodysesthesia. The study did not meet the primary endpoint of improved PFS over capecitabine or demonstrate a relative risk/benefit improvement over capecitabine.Funding provided by Celldex Therapeutics, Inc

    Aberrant activation of NF-κB signaling in mammary epithelium leads to abnormal growth and ductal carcinoma in situ

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    Gating strategy for FLOW cytometry data in Fig.  7b . An average of 100,000 events were counted for each sample. To start, all samples were taken through the first three gates (top, labeled 1, 2, 3), which excluded artifacts that were not single-cells based on forward and side scatter. From there, DAPI stain was used to determine viability (gate 4). All DAPI negative cells were carried to gate 5, where cells were split into CD45 positive and CD45 negative populations. The CD45 positive population was then gated using F4/80 on the x axis and CD45 on the y axis (gate 6). Circles indicate CD45 + F4/80+ cells. Values for the graph in Fig. 7b were obtained by taking the total number of CD45+F4/80+ cells counted for each sample and dividing that value by the total number of viable cells counted in the sample (DAPI negative). (PDF 309 kb

    Extreme Space Weather Events and Charging Hazard Assessments in Lunar Environments

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    The sunlit lunar surface charges to positive potentials with mean values of a few tens of volts where photoelectron currents dominate the charging process. In contrast, surfaces in darkness may charge to negative potentials on the order of a few hundred volts when the charging process is dominated by hot electron populations in the absence of solar photons. Recently, observations of electron beams measured by instruments on spacecraft in low lunar orbit have been interpreted as evidence for extreme lunar surface potentials exceeding a few kilovolts suggesting that lunar orbital and surface plasma environments may contain charging risks similar to geostationary orbit during extreme space weather conditions. Space system design for successful operation in a wide range of lunar environments will therefore require evaluation of charging hazards during extreme space weather conditions. We present results from a study of space weather environments conducted to obtained credible extreme charging environments for use in charging hazard assessments for lunar missions including extreme conditions encountered when the Moon is in the solar wind, the magnetosheath, and the Earth's magnetotail

    The effect of Staphylococcus aureus carriage in late pregnancy on antibody levels to staphylococcal toxins in cord blood and breast milk.

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    We investigated the effect of carriage of Staphylococcus aureus in the later stages of pregnancy on levels of antibody specific to the S. aureus toxins, staphylococcal enterotoxin B (SEB), staphylococcal enterotoxin C (SEC) and toxic shock syndrome toxin-1 (TSST-1), in cord blood and breast milk and also explored the relationship between levels of antibody in antenatal serum and cord blood. Nasopharyngeal swabs and stool samples were collected on two occasions, from 96 women, during the last 6 weeks of pregnancy. Samples were cultured and S. aureus isolates were identified. Antenatal and cord blood samples from the same women and their infants were analysed for IgG antibody to SEB, SEC and TSST-1 by enzyme-linked immunosorbent assay. Breast milk samples were analysed for IgA antibody to the same toxins. We found that S. aureus carriage in pregnancy is common and exposure to a toxin-producing isolate boosts immunity. Over 89% of women and infants have some protective antibody to the toxins, and antitoxin IgG levels are higher in cord blood samples compared with antenatal samples. Levels of cord blood IgG and breast milk IgA specific for the staphylococcal toxins vary. Some infants lack protection and could be at risk of toxin-induced disease

    Immunoelectron microscopic localization of HLA-DR antigen in control small intestine and colon and in inflammatory bowel disease

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    We have elucidated the distribution of I2 (HLA-DR) antigen in control and inflammatory bowel disease specimens, using immunoelectron microscopic methods. Control small intestinal epithelium and inflammatory bowel disease epithelium expressed I2 antigen, while control colonic epithelium did not. I2 expression by enterocytes was more frequent on the lateral and basal surface than on the microvillus surface. Two of three M cells in control ileum expressed I2 antigen. I2-positive intraepithelial lymphocytes were rarely detected in both control and disease specimens. I2-positive lamina propria lymphocytes were significantly increased in inflammatory bowel disease, while I2-positive lamina propria lymphocytes were virtually absent in control specimens. I2-positive mononuclear cells in the intestinal lamina propria were largely macrophages and monocytes in both control and inflammatory bowel disease specimens. I2-positive mononuclear cells resembling dendritic cells were not detected in control or disease specimens. Furthermore, there were no significant morphological differences in I2-positive or-negative macrophages and monocytes in control and disease specimens. The expression of I2 antigen on Schwann cells was detected more frequently in disease specimens than in control specimens. Capillary endothelia of both control and disease specimens expressed I2 antigen. We demonstrate that I2 expression is present on surface membranes of both immune and nonimmune cells of the intestine and colon and show that this expression is more prominent in inflammatory bowel disease than in control intestine and colon. Further studies are required to determine whether this finding is meaningful in terms of antigen presentation and whether this apparent “immune activation” is involved in the pathogenesis of inflammatory bowel disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44398/1/10620_2005_Article_BF01299810.pd

    Bacterial Colony Counts During Vaginal Surgery

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    Objective: To describe the bacterial types and colony counts present before and during vaginal surgery. Methods: A descriptive study was undertaken of patients undergoing vaginal hysterectomy with or without reconstructive pelvic surgery. Aerobic and anaerobic bacterial cultures were obtained immediately before and throughout the surgical cases at preselected time intervals. Standard antimicrobial prophylaxis was administered in all cases. Mean total colony counts and mean anaerobic colony counts were determined by adding all colonies regardless of bacteria type. ‘Contamination’ was defined as ≥ 5000 colony-forming units/ml. Results: A total of 31 patients aged 26 to 82 years (mean age ± SD, 51 ± 15) were included. The highest total and anaerobic colony counts were found at the first intraoperative time interval. On the first set of cultures (30 minutes after the surgical scrub), 52% (16/31) of the surgical fields were contaminated, and at 90 minutes, 41% (12/29) were contaminated. A negligible number of subsequent cultures were contaminated. Conclusions: Any future interventions designed to minimize bacterial colony counts should focus on the first 30 to 90 minutes of surgery
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