1,581 research outputs found
Medical Device Innovation in Massachusetts -- M2D2: Massachusetts Medical Device Development Center
This presentation describes the role of the medical device industry in the economy of Massachusetts and how the Massachusetts Medical Device Development (M2D2) Center can assist entrepreneurs and new companies working in this space
Differential and numerical models of hysteretic systems with stochastic and deterministic inputs
Many deterministic models with hysteresis have been developed in the areas of economics, finance, terrestrial hydrology and biology. These models lack any stochastic element which can often have a strong effect in these areas. In this work stochastically driven closed loop systems with hysteresis type memory are studied. This type of system is presented as a possible stochastic counterpart to deterministic models in the areas of economics, finance, terrestrial hydrology and biology. Some price dynamics models are presented as a motivation for the development of this type of model. Numerical schemes for solving this class of stochastic differential equation are developed in order to examine the prototype models presented. As a means of further testing the developed numerical schemes, numerical examination is made of the behaviour near equilibrium of coupled ordinary differential equations where the time derivative of the Preisach operator is included in one of the equations. A model of two phenotype bacteria is also presented. This model is examined to explore memory effects and related hysteresis effects in the area of biology. The memory effects found in this model are similar to that found in the non-ideal relay. This non-ideal relay type behaviour is used to model a colony of bacteria with multiple switching thresholds. This model contains a Preisach type memory with a variable Preisach weight function. Shown numerically for this multi-threshold model is a pattern formation for the distribution of the phenotypes among the available thresholds
Resident macrophages of pancreatic islets have a seminal role in the initiation of autoimmune diabetes of NOD mice
Significance
Our studies indicate that the resident macrophages of the pancreatic islets of Langerhans have a seminal role in the initiation and progression of autoimmune diabetes in NOD mice. In this study, islet macrophages were depleted by administration of a monoclonal antibody to the CSF-1 receptor. Macrophage depletion, either at the start of the autoimmune process or when diabetogenesis is active, leads to a significant reduction in diabetes incidence. Depletion of the islet macrophages reduces the entrance of T cells into islets and results in the absence of antigen presentation. Concordantly, a regulatory pathway develops that controls diabetes progression. We conclude that treatments that target the islet macrophages may have important clinical relevance for the control of autoimmune type 1 diabetes.</jats:p
Long-term efficacy and safety of first-line ibrutinib treatment for patients with CLL/SLL: 5 years of follow-up from the phase 3 RESONATE-2 study.
RESONATE-2 is a phase 3 study of first-line ibrutinib versus chlorambucil in chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Patients aged ≥65 years (n = 269) were randomized 1:1 to once-daily ibrutinib 420 mg continuously or chlorambucil 0.5-0.8 mg/kg for ≤12 cycles. With a median (range) follow-up of 60 months (0.1-66), progression-free survival (PFS) and overall survival (OS) benefits for ibrutinib versus chlorambucil were sustained (PFS estimates at 5 years: 70% vs 12%; HR [95% CI]: 0.146 [0.098-0.218]; OS estimates at 5 years: 83% vs 68%; HR [95% CI]: 0.450 [0.266-0.761]). Ibrutinib benefit was also consistent in patients with high prognostic risk (TP53 mutation, 11q deletion, and/or unmutated IGHV) (PFS: HR [95% CI]: 0.083 [0.047-0.145]; OS: HR [95% CI]: 0.366 [0.181-0.736]). Investigator-assessed overall response rate was 92% with ibrutinib (complete response, 30%; 11% at primary analysis). Common grade ≥3 adverse events (AEs) included neutropenia (13%), pneumonia (12%), hypertension (8%), anemia (7%), and hyponatremia (6%); occurrence of most events as well as discontinuations due to AEs decreased over time. Fifty-eight percent of patients continue to receive ibrutinib. Single-agent ibrutinib demonstrated sustained PFS and OS benefit versus chlorambucil and increased depth of response over time
A nested hierarchical perspective to enhance interpretations and communication in fluvial geomorphology for use in water resources management::Lessons from the Okavango Delta, Botswana
Childcare, choice and social class: Caring for young children in the UK
This paper draws on the results of two qualitative research projects examining parental engagements with the childcare market in the UK. Both projects are located in the same two London localities. One project focuses on professional middle class parents, and the other on working class families, and we discuss the key importance of social class in shaping parents' differential engagement with the childcare market, and their understandings of the role childcare plays in their children's lives. We identify and discuss the different "circuits" of care (Ball et al 1995) available to and used by families living physically close to each other, but in social class terms living in different worlds. We also consider parents' relationships with carers, and their social networks. We conclude that in order to fully understand childcare policies and practices and families' experiences of care, an analysis which encompasses social class and the workings of the childcare market is needed
A vision-based hole quality assessment technique for robotic drilling of composite materials using a hybrid classification model
peer reviewedRobotic drilling has advantages over traditional computer numerical control machines due to its flexibility, dexterity and the potential for rapid production and process automation. The dexterity and reach of the robotic drill end effector enables the efficient drilling of large composite components, such as aircraft wing structures. Due to the anisotropy and inhomogeneity of fibre reinforced polymer composite materials, drilling remains a challenging task. Inspection of the drilled hole is required at the end of the process to ensure the final product is free from defects. Typically, such inspections require the parts to be transferred to a dedicated inspection station, which is a time-consuming non-value-added task and impractical for large components. In the interest of an efficient and sustainable manufacturing process, this work proposes a hybrid classification model implemented with a robotic drilling system to investigate the quality of drilled holes in-situ. The classifier is trained and tested with a random selection of drilled holes and the most accurate classifier is implemented. The selected classifier returns 90% overall prediction accuracy on unseen drilled holes. This machine learning based approach, using a convolutional neural network and support vector machine classifier, can significantly improve inspection reliability while reducing production time for drilled composite components. This is the first study that demonstrates a hole quality assessment technique for robotic drilling of composite material in-situ at scale
Faint NUV/FUV Standards from Swift/UVOT, GALEX and SDSS Photometry
At present, the precision of deep ultraviolet photometry is somewhat limited
by the dearth of faint ultraviolet standard stars. In an effort to improve this
situation, we present a uniform catalog of eleven new faint (u sim17)
ultraviolet standard stars. High-precision photometry of these stars has been
taken from the Sloan Digital Sky Survey and Galaxy Evolution Explorer and
combined with new data from the Swift Ultraviolet Optical Telescope to provide
precise photometric measures extending from the Near Infrared to the Far
Ultraviolet. These stars were chosen because they are known to be hot (20,000 <
T_eff < 50,000 K) DA white dwarfs with published Sloan spectra that should be
photometrically stable. This careful selection allows us to compare the
combined photometry and Sloan spectroscopy to models of pure hydrogen
atmospheres to both constrain the underlying properties of the white dwarfs and
test the ability of white dwarf models to predict the photometric measures. We
find that the photometry provides good constraint on white dwarf temperatures,
which demonstrates the ability of Swift/UVOT to investigate the properties of
hot luminous stars. We further find that the models reproduce the photometric
measures in all eleven passbands to within their systematic uncertainties.
Within the limits of our photometry, we find the standard stars to be
photometrically stable. This success indicates that the models can be used to
calibrate additional filters to our standard system, permitting easier
comparison of photometry from heterogeneous sources. The largest source of
uncertainty in the model fitting is the uncertainty in the foreground reddening
curve, a problem that is especially acute in the UV.Comment: Accepted for publication in Astrophysical Journal. 31 pages, 13
figures, electronic tables available from ApJ or on reques
Abatacept Pharmacokinetics and Exposure Response in Patients Hospitalized With COVID-19: A Secondary Analysis of the ACTIV-1 IM Randomized Clinical Trial
IMPORTANCE: The pharmacokinetics of abatacept and the association between abatacept exposure and outcomes in patients with severe COVID-19 are unknown.
OBJECTIVE: To characterize abatacept pharmacokinetics, relate drug exposure with clinical outcomes, and evaluate the need for dosage adjustments.
DESIGN, SETTING, AND PARTICIPANTS: This study is a secondary analysis of data from the ACTIV-1 (Accelerating COVID-19 Therapeutic Interventions and Vaccines) Immune Modulator (IM) randomized clinical trial conducted between October 16, 2020, and December 31, 2021. The trial included hospitalized adults who received abatacept in addition to standard of care for treatment of COVID-19 pneumonia. Data analysis was performed between September 2022 and February 2024.
EXPOSURE: Single intravenous infusion of abatacept (10 mg/kg with a maximum dose of 1000 mg).
MAIN OUTCOMES AND MEASURES: Mortality at day 28 was the primary outcome of interest, and time to recovery at day 28 was the secondary outcome. Drug exposure was assessed using the projected area under the serum concentration time curve over 28 days (AUC0-28). Logistic regression modeling was used to analyze the association between drug exposure and 28-day mortality, adjusted for age, sex, and disease severity. The association between time to recovery and abatacept exposure was examined using Fine-Gray modeling with death as a competing risk, and was adjusted for age, sex, and disease severity.
RESULTS: Of the 509 patients who received abatacept, 395 patients with 848 serum samples were included in the population pharmacokinetic analysis. Their median age was 55 (range, 19-89) years and most (250 [63.3%]) were men. Abatacept clearance increased with body weight and more severe disease activity at baseline. Drug exposure was higher in patients who survived vs those who died, with a median AUC0-28 of 21 428 (range, 8462-43 378) mg × h/L vs 18 262 (range, 9628-27 507) mg × h/L (P \u3c .001). Controlling for age, sex, and disease severity, an increase of 5000 units in AUC0-28 was associated with lower odds of mortality at day 28 (OR, 0.52 [95% CI, 0.35-0.79]; P = .002). For an AUC0-28 of 19 400 mg × h/L or less, there was a higher probability of recovery at day 28 (hazard ratio, 2.63 [95% CI, 1.70-4.08] for every 5000-unit increase; P \u3c .001). Controlling for age, sex, and disease severity, every 5000-unit increase in AUC0-28 was also associated with lower odds of a composite safety event at 28 days (OR, 0.46 [95% CI, 0.33-0.63]; P \u3c .001). Using the dosing regimen studied in the ACTIV-1 IM trial, 121 of the 395 patients (30.6%) would not achieve an abatacept exposure of at least 19 400 mg × h/L, particularly at the extremes of body weight. Using a modified, higher-dose regimen, only 12 patients (3.0%) would not achieve the hypothesized target abatacept exposure.
CONCLUSIONS AND RELEVANCE: In this study, patients who were hospitalized with severe COVID-19 and achieved higher projected abatacept exposure had reduced mortality and a higher probability of recovery with fewer safety events. However, abatacept clearance was high in this population, and the current abatacept dosing (10 mg/kg intravenously with a maximum of 1000 mg) may not achieve optimal exposure in all patients.
TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04593940
Unveiling the nature of INTEGRAL objects through optical spectroscopy. VIII. Identification of 44 newly detected hard X-ray sources
(abridged) Hard X-ray surveys performed by the INTEGRAL satellite have
discovered a conspicuous fraction (up to 30%) of unidentified objects among the
detected sources. Here we continue our identification program by selecting
probable optical candidates using positional cross-correlation with soft X-ray,
radio, and/or optical archives, and performing optical spectroscopy on them. As
a result, we identified or more accurately characterized 44 counterparts of
INTEGRAL sources: 32 active galactic nuclei, with redshift 0.019 < z < 0.6058,
6 cataclysmic variables (CVs), 5 high-mass X-ray binaries (2 of which in the
Small Magellanic Cloud), and 1 low-mass X-ray binary. This was achieved by
using 7 telescopes of various sizes and archival data from two online
spectroscopic surveys. The main physical parameters of these hard X-ray sources
were also determined using the available multiwavelength information. AGNs are
the most abundant population among hard X-ray objects, and our results confirm
this tendency when optical spectroscopy is used as an identification tool. The
deeper sensitivity of recent INTEGRAL surveys enables one to begin detecting
hard X-ray emission above 20 keV from sources such as LINER-type AGNs and
non-magnetic CVs.Comment: 22 pages, 14 figures, 6 tables, accepted for publication on A&A, main
journa
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