499 research outputs found
Measurements of the reverse current of highly irradiated silicon sensors to determine the effective energy and current related damage rate
The reverse current of irradiated silicon sensors leads to self heating of the sensor and degrades the signal to noise ratio of a detector. Precise knowledge of the expected reverse current during detector operation is crucial for planning and running experiments in High Energy Physics. The dependence of the reverse current on sensor temperature and irradiation fluence is parametrized by the effective energy and the current related damage rate, respectively. In this study 18 n-in-p mini silicon strip sensors from companies Hamamatsu Photonics and Micron Semiconductor Ltd. were deployed. Measurements of the reverse current for different bias voltages were performed at temperatures of −32 ° C, −27 ° C and −23 ° C. The sensors were irradiated with reactor neutrons in Ljubljana to fluences ranging from 2×1014neq∕cm2 to 2×1016neq∕cm2 . The measurements were performed directly after irradiation and after 10 and 30 days of room temperature annealing. The aim of the study presented in this paper is to investigate the reverse current of silicon sensors for high fluences of up to 2×1016neq∕cm2 and compare the measurements to the parametrization models
A toolset of functionalized porphyrins with different linker strategies for application in bioconjugation
The reaction of amines with pentafluorophenyl-substituted A3B-porphyrins has
been used to obtain different useful reactive groups for further
functionalization and/or conjugation of these porphyrins to other substrates
or materials. Porphyrins with alkenyl, alkynyl, amino, azido, epoxide,
hydroxyl, and maleimido groups have thus been synthesized. For the first time
such functionalized porphyrins have been conjugated to hyperbranched
polyglycerol (hPG) as a biocompatible carrier system for photodynamic therapy
(PDT) using the copper(I)-catalyzed 1,3-dipolar cycloaddition (CuAAC). The
photocytotoxicity of selected porphyrins as well as of the porphyrin-hPG-
conjugates has been assessed in cellular assays with human epidermoid
carcinoma A-253 and squamous carcinoma CAL-27 cells. For several biomedical
applications a release of the active drug and/or fluorescent dye is desired.
Therefore, additionally, the synthesis of A3B-porphyrins with cleavable linker
moieties is presented, namely disulfide, cleavable in a reductive environment,
and acetal linkers whose cleavage is pH triggered
A PRELIMINARY STUDY OF THE EFFECT OF SURFACE COATING ON THE INITIAL DEPOSITION MECHANISMS OF DAIRY FOULING
Adolescent Burmese Refugees Perspectives on Determinants of Health
Over 70,000 Burmese refugees have resettled in the United States in the past decade. While Burmese adolescents quickly acculturate into American society, their perspectives on health are not well-known. The purpose of this study was to identify adolescent Burmese refugee perspectives on determinants of health and health-related experiences after resettlement. In this qualitative study, Burmese adolescents took photographs depicting health-related experiences that were used as elicitation tools during focus groups. These discussions were recorded, transcribed, and analyzed for themes. Participants described positive determinants of health, including family and church. Rampant tobacco use was identified by the participants as a determinant of poor health within the Burmese community. Notably, the participants were proud to serve as liaisons within their community, despite the stressful nature of this role. Our results highlight the need to screen this population for anxiety, secondary to serving as a liaison for their community, as well as tobacco use
Codesigned Shared Decision-Making Diabetes Management Plan Tool for Adolescents With Type 1 Diabetes Mellitus and Their Parents: Prototype Development and Pilot Test
Background: Adolescents with type 1 diabetes mellitus have difficulty achieving optimal glycemic control, partly due to competing priorities that interfere with diabetes self-care. Often, significant diabetes-related family conflict occurs, and adolescents’ thoughts and feelings about diabetes management may be disregarded. Patient-centered diabetes outcomes may be better when adolescents feel engaged in the decision-making process.
Objective: The objective of our study was to codesign a clinic intervention using shared decision making for addressing diabetes self-care with an adolescent patient and parent advisory board.
Methods: The patient and parent advisory board consisted of 6 adolescents (teens) between the ages 12 and 18 years with type 1 diabetes mellitus and their parents recruited through our institution’s Pediatric Diabetes Program. Teens and parents provided informed consent and participated in 1 or both of 2 patient and parent advisory board sessions, lasting 3 to 4 hours each. Session 1 topics were (1) patient-centered outcomes related to quality of life, parent-teen shared diabetes management, and shared family experiences; and (2) implementation and acceptability of a patient-centered diabetes care plan intervention where shared decision making was used. We analyzed audio recordings, notes, and other materials to identify and extract ideas relevant to the development of a patient-centered diabetes management plan. These data were visually coded into similar themes. We used the information to develop a prototype for a diabetes management plan tool that we pilot tested during session 2.
Results: Session 1 identified 6 principal patient-centered quality-of-life measurement domains: stress, fear and worry, mealtime struggles, assumptions and judgments, feeling abnormal, and conflict. We determined 2 objectives to be principally important for a diabetes management plan intervention: (1) focusing the intervention on diabetes distress and conflict resolution strategies, and (2) working toward a verbalized common goal. In session 2, we created the diabetes management plan tool according to these findings and will use it in a clinical trial with the aim of assisting with patient-centered goal setting.
Conclusions: Patients with type 1 diabetes mellitus can be effectively engaged and involved in patient-centered research design. Teens with type 1 diabetes mellitus prioritize reducing family conflict and fitting into their social milieu over health outcomes at this time in their lives. It is important to acknowledge this when designing interventions to improve health outcomes in teens with type 1 diabetes mellitus
Finite-size scaling of the quasiespecies model
We use finite-size scaling to investigate the critical behavior of the
quasiespecies model of molecular evolution in the single-sharp-peak replication
landscape. This model exhibits a sharp threshold phenomenon at Q=Q_c=1/a, where
Q is the probability of exact replication of a molecule of length L and a is
the selective advantage of the master string.
We investigate the sharpness of the threshold and find that its
characteristic persist across a range of Q of order L^(-1) about Q_c.
Furthermore, using the data collapsing method we show that the normalized mean
Hamming distance between the master string and the entire population, as well
as the properly scaled fluctuations around this mean value, follow universal
forms in the critical region.Comment: 8 pages,tex. Submitted to Physical Review
Visual Working Memory Recruits Two Functionally Distinct Alpha Rhythms in Posterior Cortex
Copyright © 2022 Rodriguez-Larios et al. Oscillatory activity in the human brain is dominated by posterior alpha oscillations (8–14 Hz), which have been shown to be functionally relevant in a wide variety of cognitive tasks. Although posterior alpha oscillations are commonly considered a single oscillator anchored at an individual alpha frequency (∼10 Hz), previous work suggests that individual alpha frequency reflects a spatial mixture of different brain rhythms. In this study, we assess whether independent component analysis (ICA) can disentangle functionally distinct posterior alpha rhythms in the context of visual short-term memory retention. Magnetoencephalography (MEG) was recorded in 33 subjects while performing a visual working memory task. Group analysis at sensor level suggested the existence of a single posterior alpha oscillator that increases in power and decreases in frequency during memory retention. Conversely, single-subject analysis of independent components revealed the existence of two dissociable alpha rhythms: one that increases in power during memory retention (Alpha1) and another one that decreases in power (Alpha2). Alpha1 and Alpha2 rhythms were differentially modulated by the presence of visual distractors (Alpha1 increased in power while Alpha2 decreased) and had an opposite relationship with accuracy (positive for Alpha1 and negative for Alpha2). In addition, Alpha1 rhythms showed a lower peak frequency, a narrower peak width, a greater relative peak amplitude and a more central source than Alpha2 rhythms. Together, our results demonstrate that modulations in posterior alpha oscillations during short-term memory retention reflect the dynamics of at least two distinct brain rhythms with different functions and spatiospectral characteristics.The Netherlands Organisation for Scientific Research (NWO) Vidi Grant 016.Vidi.185.137; National Institutes of Health Grant R01-MH123679
Patient journey experiences may contribute to improve healthcare for patients with rare endocrine diseases
Patient journeys are instruments developed by EURORDIS, The Voice of Rare Disease Patients in Europe, to collect patients' experiences; they may identify gaps and areas deserving improvement, as well as elements positively considered by affected persons. As with other patient-reported experiences, they can complete the clinical evaluation and management of a specific disease, improving the often long diagnostic delay, therapy, patient education and access to knowledgeable multidisciplinary teams. This review discusses the utility of such patient-reported experience measures and summarises the experiences of patients with acromegaly, Addison's disease and congenital adrenal hyperplasia from different European countries. Despite rare endocrine diseases being varied and presenting differently, feelings of not having been taken seriously by health professionals, family and friends was a common patient complaint. Empathy and a positive patient-centred environment tend to improve clinical practice by creating a trustworthy and understanding atmosphere, where individual patient needs are considered. Offering access to adequate patient information on their disease, treatments and outcome helps to adapt to living with a chronic disease and what to expect in the future, contemplating the impact of a disease on patients' everyday life, not only clinical outcome but also social, financial, educational, family and leisure issues is desirable; this facilitates more realistic expectancies for patients and can even lead to a reduction in health costs. Patient empowerment with patient-centred approaches to these complex or chronic diseases should be contemplated more and more, not only for the benefit of those affected but also for the entire health system
Using GPS-enabled cell phones to track the travel patterns of adolescents
<p>Abstract</p> <p>Background</p> <p>Few tools exist to directly measure the microsocial and physical environments of adolescents in circumstances where participatory observation is not practical or ethical. Yet measuring these environments is important as they are significantly associated with adolescent health-risk. For example, health-related behaviors such as cigarette smoking often occur in specific places where smoking may be relatively surreptitious.</p> <p>Results</p> <p>We assessed the feasibility of using GPS-enabled cell phones to track adolescent travel patterns and gather daily diary data. We enrolled 15 adolescent women from a clinic-based setting and asked them to carry the phones for 1 week. We found that these phones can accurately and reliably track participant locations, as well as record diary information on adolescent behaviors. Participants had variable paths extending beyond their immediate neighborhoods, and denied that GPS-tracking influenced their activity.</p> <p>Conclusion</p> <p>GPS-enabled cell phones offer a feasible and, in many ways, ideal modality of monitoring the location and travel patterns of adolescents. In addition, cell phones allow space- and time-specific interaction, probing, and intervention which significantly extends both research and health promotion beyond a clinical setting. Future studies can employ GPS-enabled cell phones to better understand adolescent environments, how they are associated with health-risk behaviors, and perhaps intervene to change health behavior.</p
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