Carbon fiber substitution in shipboard instrument structural mounts for vibration and shock isolation

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 27).Insufficient support and isolation of rotating and non-rotating shipboard equipment and instruments may cause damage to the components or the ship itself. Reduction of noise emissions to the ship's hull and protection of equipment from outside disturbances may be attained through isolator mounting systems. The objective of this thesis is to investigate and analyze the effects of substituting carbon fiber reinforced polymer (CFRP) for use in the structural mounts on rotating marine diesel engines and on sensitive, nonrotating Electronic Chart Display and Information Systems (ECDIS). The high specific stiffness of CFRP make it an interesting candidate for mounting material substitution. The shipboard components were modeled with mounts made of steel, rubber and CFRP and their step response, impulse response and transmissibility behavior were analyzed. It was concluded that the choice in appropriate mounting materials depends on the application, but CFRP was found in many cases to display similar vibration isolation behavior to steel while being much less dense.by Anna C. Haas.S.B

Behavioral and Other Phenotypes in a Cytoplasmic Dynein Light Intermediate Chain 1 Mutant Mouse

The cytoplasmic dynein complex is fundamentally important to all eukaryotic cells for transporting a variety of essential cargoes along microtubules within the cell. This complex also plays more specialized roles in neurons. The complex consists of 11 types of protein that interact with each other and with external adaptors, regulators and cargoes. Despite the importance of the cytoplasmic dynein complex, we know comparatively little of the roles of each component protein, and in mammals few mutants exist that allow us to explore the effects of defects in dynein-controlled processes in the context of the whole organism. Here we have taken a genotype-driven approach in mouse (Mus musculus) to analyze the role of one subunit, the dynein light intermediate chain 1 (Dync1li1). We find that, surprisingly, an N235Y point mutation in this protein results in altered neuronal development, as shown from in vivo studies in the developing cortex, and analyses of electrophysiological function. Moreover, mutant mice display increased anxiety, thus linking dynein functions to a behavioral phenotype in mammals for the first time. These results demonstrate the important role that dynein-controlled processes play in the correct development and function of the mammalian nervous system

Biomechanical analysis of the knee during an immersive, high-intensity exergame training in healthy athletes

Introduction: Exergaming – physically active gaming – is cognitively and physically challenging, and, therefore, has great potential for sports rehabilitation, for example after knee injuries. Before it can be recommended for rehabilitation, the biomechanics during exergaming needs to be understood. The occurrence of high-risk movement patterns for knee injuries, an abducted, internally rotated knee at 10-30° of flexion, needs to be monitored [1,2]. This study aimed to compare the amount of knee valgus (KV) and knee internal rotation (KIR) at 10-30° of knee flexion during different exercises of an immersive, high-intensive exergame in healthy athletes. Materials and Methods: Kinematics during a 25-minute exergame training (ExerCube) [3] were measured using marker-based motion capture (Vicon) in 18 athletes (9 female, 9 male) without prior knee injuries. The mean maximal KV and KIR angle during 10°- 30° knee flexion were compared between 9 exercises [4] using a two-way within-subject linear mixed model with post-hoc t-test. Results: A significantly higher KV compared to the other exercises, was found during the punch to the ipsilateral side of the investigated knee (Mean 8.5° (Standard Deviation 0.04°)) and high-touch to the contralateral side (8.5° (0.1°)). In addition, the ipsilateral KIR of the punch (13.2° (0.9°)), the high-touch (11.7° (0.6°)), and mid-touch (10.9° (1.3°)) were significantly larger than in the other exercises. Conclusion: High-touches, mid-touches, and punches result in knee kinematics related to an increased risk of injury in healthy athletes. The inclusion of these movements during exergame-based rehabilitation should be carefully managed and performed in later stages of rehabilitation

IGRT/ART phantom with programmable independent rib cage and tumor motion

Abstract PURPOSE: This paper describes the design and experimental evaluation of the Methods and Advanced Equipment for Simulation and Treatment in Radiation Oncology (MAESTRO) thorax phantom, a new anthropomorphic moving ribcage combined with a 3D tumor positioning system to move target inserts within static lungs. METHODS: The new rib cage design is described and its motion is evaluated using Vicon Nexus, a commercial 3D motion tracking system. CT studies at inhale and exhale position are used to study the effect of rib motion and tissue equivalence. RESULTS: The 3D target positioning system and the rib cage have millimetre accuracy. Each axis of motion can reproduce given trajectories from files or individually programmed sinusoidal motion in terms of amplitude, period, and phase shift. The maximum rib motion ranges from 7 to 20 mm SI and from 0.3 to 3.7 mm AP with LR motion less than 1 mm. The repeatability between cycles is within 0.16 mm root mean square error. The agreement between CT electron and mass density for skin, ribcage, spine hard and inner bone as well as cartilage is within 3%. CONCLUSIONS: The MAESTRO phantom is a useful research tool that produces programmable 3D rib motions which can be synchronized with 3D internal target motion. The easily accessible static lungs enable the use of a wide range of inserts or can be filled with lung tissue equivalent and deformed using the target motion system.status: publishe

A Phase II Trial of the Epothilone B Analog Ixabepilone (BMS-247550) in Patients with Metastatic Melanoma

Ixabepilone (BMS-247550), an epothilone B analog, is a microtubule stabilizing agent which has shown activity in several different tumor types and preclinical models in melanoma. In an open label, one-arm, multi-center phase II trial the efficacy and toxicity of this epothilone was investigated in two different cohorts: chemotherapy-naïve (previously untreated) and previously treated patients with metastatic melanoma.Eligible patients had histologically-confirmed stage IV melanoma, with an ECOG performance status of 0 to 2. Ixabepilone was administered at a dose of 20 mg/m(2) on days 1, 8, and 15 during each 28-day cycle. The primary endpoint was response rate (RR); secondary endpoints were time to progression (TTP) and toxicity. Twenty-four patients were enrolled and 23 were evaluable for response. Initial serum lactate dehydrogenase (LDH) levels were elevated in 6/11 (55%) of the previously treated and in 5/13 (38%) of the previously untreated patients. No complete or partial responses were seen in either cohort. One patient in the previously treated group developed neutropenia and fatal septic shock. Seventeen patients (8 in the previously untreated group and 9 in the previously treated group) progressed after 2 cycles, whereas six patients (3 in each group) had stable disease after 2-6 cycles. Median TTP was 1.74 months in the previously untreated group (95% CI = 1.51 months, upper limit not estimated) and 1.54 months in the previously treated group (95% CI = 1.15 months, 2.72 months). Grade 3 and/or 4 toxicities occurred in 5/11 (45%) of previously untreated and in 5/13 (38%) of previously treated patients and included neutropenia, peripheral neuropathy, fatigue, diarrhea, and dyspnea.Ixabepilone has no meaningful activity in either chemotherapy-naïve (previously untreated) or previously treated patients with metastatic melanoma. Further investigation with ixabepilone as single agent in the treatment of melanoma is not warranted.Clinical Trials.gov NCT00036764

Missed Opportunities: Family History and Behavioral Risk Factors in Breast Cancer Risk Assessment Among a Multiethnic Group of Women

BACKGROUND: Clinician’s knowledge of a woman’s cancer family history (CFH) and counseling about health-related behaviors (HRB) is necessary for appropriate breast cancer care. OBJECTIVE: To evaluate whether clinicians solicit CFH and counsel women on HRB; to assess relationship of well visits and patient risk perception or worry with clinician’s behavior. DESIGN: Cross-sectional population-based telephone survey. PARTICIPANTS: Multiethnic sample; 1,700 women from San Francisco Mammography Registry with a screening mammogram in 2001–2002. MEASUREMENTS: Predictors: well visit in prior year, self-perception of 10-year breast cancer risk, worry scale. Outcomes: Patient report of clinician asking about CFH in prior year, or ever counseling about HRB in relation to breast cancer risk. Multivariate models included age, ethnicity, education, language of interview, insurance/mammography facility, well visit, ever having a breast biopsy/follow-up mammography, Gail-Model risk, Jewish heritage, and body mass index. RESULTS: 58% reported clinicians asked about CFH; 33% reported clinicians ever discussed HRB. In multivariate analysis, regardless of actual risk, perceived risk, or level of worry, having had a well visit in prior year was associated with increased odds (OR = 2.3; 95% CI 1.6, 3.3) that a clinician asked about CFH. Regardless of actual risk of breast cancer, a higher level of worry (OR = 1.9; 95% CI 1.4, 2.6) was associated with increased odds that a clinician ever discussed HRB. CONCLUSIONS: Clinicians are missing opportunities to elicit family cancer histories and counsel about health-related behaviors and breast cancer risk. Preventive health visits offer opportunities for clinicians to address family history, risk behaviors, and patients’ worries about breast cancer

pERK, pAKT and p53 as tissue biomarkers in erlotinib-treated patients with advanced pancreatic cancer: a translational subgroup analysis from AIO-PK0104

Background: The role of pERK, pAKT and p53 as biomarkers in patients with advanced pancreatic cancer has not yet been defined. Methods: Within the phase III study AIO-PK0104 281 patients with advanced pancreatic cancer received an erlotinib-based 1st-line regimen. Archival tissue from 153 patients was available for central immunohistochemistry staining for pERK, pAKT and p53. Within a subgroup analysis, biomarker data were correlated with efficacy endpoints and skin rash using a Cox regression model. Results: Fifty-five out of 153 patients were classified as pERK(low) and 98 patients as pERK(high); median overall survival (OS) was 6.2 months and 5.7 months, respectively (HR 1.29, p = 0.16). When analysing pERK as continuous variable, the pERK score was significantly associated with OS (HR 1.06, 95% CI 1.0-1.12, p = 0.05). Twenty-one of 35 patients were pAKT(low) and 14/35 pAKT(high) with a corresponding median OS of 6.4 months and 6.8 months, respectively (HR 1.03, p = 0.93). Four out of 50 patients had a complete loss of p53 expression, 20 patients a regular expression and 26 patients had tumors with p53 overexpression. The p53 status had no impact on OS (p = 0.91); however, a significant improvement in progression-free survival (PFS) (6.0 vs 1.8 months, HR 0.24, p = 0.02) and a higher rate of skin rash (84% vs 25%, p = 0.02) was observed for patients with a regular p53 expression compared to patients with a complete loss of p53. Conclusion: pERK expression may have an impact on OS in erlotinib-treated patients with advanced pancreatic cancer; p53 should be further investigated for its potential role as a predictive marker for PFS and skin rash

Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target

Multiplicities of charged pions and unidentified hadrons produced in deep-inelastic scattering were measured in bins of the Bjorken scaling variable $x$, the relative virtual-photon energy $y$ and the relative hadron energy $z$. Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and an isoscalar target ($^6$LiD). They cover the kinematic domain in the photon virtuality $Q^2$ > 1(GeV/c$)^2$, $0.004 < x < 0.4$, $0.2 < z < 0.85$ and $0.1 < y < 0.7$. In addition, a leading-order pQCD analysis was performed using the pion multiplicity results to extract quark fragmentation functions

Adapting a mobile app to support patients with anorexia nervosa following post-acute care: perspectives from eating disorder treatment center stakeholders

Introduction Anorexia nervosa (AN) is a harmful, life-threatening illness. Patients with severe AN often receive acute treatment but, upon discharge, experience high relapse rates. Evidence-based, outpatient treatment following acute care is critical to preventing relapse; however, numerous barriers (e.g., location, financial limitations, low availability of providers) preclude individuals from accessing treatment. mHealth technologies may help to address these barriers, but research on such digital approaches for those with AN is limited. Further, such technologies should be developed with all relevant stakeholder input considered from the outset. As such, the present study aimed to garner feedback from eating disorder (ED) treatment center providers on (1) the process of discharging patients to outpatient services, (2) their experiences with technology as a treatment tool, and (3) how future mHealth technologies may be harnessed to offer the most benefit to patients in the post-acute period. Methods Participants (N = 11, from 7 ED treatment centers across the United States) were interviewed. To analyze the data for this study, each interview was manually transcribed and analyzed using components of Braun and Clarke's six-phase thematic analysis framework (Braun & Clarke, 2006). Results Participants indicated proactively securing outpatient care for their patients, but mentioned several barriers their patients face in accessing evidence-based ED treatment. All participants had some experience using various technologies for treatment (e.g., teletherapy, self-monitoring apps), and mentioned a high level of interest in the development of a new app to be used by patients recently discharged from acute treatment for AN. Participants also offered suggestions of effective and relevant content for a potential app and adjunctive social networking component for post-acute care of AN. Discussion Overall, participants expressed positive attitudes toward the integration of an app into the care flow, suggesting the high potential benefit of harnessing technology to support individuals recovering from AN

Genome Sequence of E. coli O104:H4 Leads to Rapid Development of a Targeted Antimicrobial Agent against This Emerging Pathogen

A recent widespread outbreak of Escherichia coli O104:H4 in Germany demonstrates the dynamic nature of emerging and re-emerging food-borne pathogens, particularly STECs and related pathogenic E. coli. Rapid genome sequencing and public availability of these data from the German outbreak strain allowed us to identify an O-antigen-specific bacteriophage tail spike protein encoded in the genome. We synthesized this gene and fused it to the tail fiber gene of an R-type pyocin, a phage tail-like bacteriocin, and expressed the novel bacteriocin such that the tail fiber fusion was incorporated into the bacteriocin structure. The resulting particles have bactericidal activity specifically against E. coli strains that produce the O104 lipopolysaccharide antigen, including the outbreak strain. This O-antigen tailspike-R-type pyocin strategy provides a platform to respond rapidly to emerging pathogens upon the availability of the pathogen's genome sequence