624 research outputs found
Blood lead levels in the elderly
Lead is ubiquitious in the environment and human tissues. Mobile and
stationary sources of anthropogenic lead tend to be concentrated in areas
of high population density. At concentrations previously regarded as
'safe', lead has been implicated in causing neurobehavioural impairment
(Needleman et al., 1990), hearing deficits (Robinson et al., 1985), growth
retardation (Schwartz et al., 1986), inhibition of haem biosynthesis
(EPA, 1986), hypertension (Harlan, 1985) and suppression of the immune
response (Hemphill et al., 1971). This study consists of the analysis of PbB in an elderly population.
Variables which may affect PbB were collected via patient medical
records and a patient interview.peer-reviewe
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A comparative analysis of two models of early childhood education on the variables of teachers\u27 conceptions of motivation and motivational strategies.
Cardiovascular function and ballistocardiogram: a relationship interpreted via mathematical modeling
Objective: to develop quantitative methods for the clinical interpretation of
the ballistocardiogram (BCG). Methods: a closed-loop mathematical model of the
cardiovascular system is proposed to theoretically simulate the mechanisms
generating the BCG signal, which is then compared with the signal acquired via
accelerometry on a suspended bed. Results: simulated arterial pressure
waveforms and ventricular functions are in good qualitative and quantitative
agreement with those reported in the clinical literature. Simulated BCG signals
exhibit the typical I, J, K, L, M and N peaks and show good qualitative and
quantitative agreement with experimental measurements. Simulated BCG signals
associated with reduced contractility and increased stiffness of the left
ventricle exhibit different changes that are characteristic of the specific
pathological condition. Conclusion: the proposed closed-loop model captures the
predominant features of BCG signals and can predict pathological changes on the
basis of fundamental mechanisms in cardiovascular physiology. Significance:
this work provides a quantitative framework for the clinical interpretation of
BCG signals and the optimization of BCG sensing devices. The present study
considers an average human body and can potentially be extended to include
variability among individuals
Cryptosporidium Parvum-Induced Inflammatory Bowel Disease of TCR-ÎČ- x TCR-ÎŽ-Deficient Mice
Experimental inoculation of neonatal immunocompetent strains of mice with Cryptosporidium parvum results in a transient, noninflammatory enteric infection. In the present study, we show that inoculation of mice deficient in a 3 and y8 T cells (TCR-3- X TCR-8-deficient mice) with C. parvum results in persistent infection and severe inflammatory bowel disease- like lesions. The most severe lesions in these mice were in the cecum with similar yet less severe lesions in the ileum and proximal colon. The most notable aspect of the histopathology was glandular hyperplasia with abscess formation, extensive fibrosis of the lamina propria with infiltrates of predominately polymorphonuclear cells and macrophages, and a few small aggregates of B cells. Persistently infected mice also developed extensive hepatic periportal fibrosis in association with C. parvum colonization of bile ducts. Lesions observed in TCR- 3- X TCR-8-deficient mice were markedly different than previously described lesions detected in C. parvum-infected TCR-o-deficient mice. Cryptosporidium parvum-infected TCR-o-deficient mice have extensive infiltrations of B cells, whereas TCR-P3- X TCR-8-deficient mice had only a few small aggregates of B cells. These findings indicate that although y8 T cells are not necessary for induction of intestinal inflammation in C. parvum-infected o(4 T- cell-deficient mice, their presence does alter the morphology of the ensuing lesion
Positive Surgical Margins in the 10 Most Common Solid Cancers.
A positive surgical margin (PSM) following cancer resection oftentimes necessitates adjuvant treatments and carries significant financial and prognostic implications. We sought to compare PSM rates for the ten most common solid cancers in the United States, and to assess trends over time. Over 10 million patients were identified in the National Cancer Data Base from 1998-2012, and 6.5 million had surgical margin data. PSM rates were compared between two time periods, 1998-2002 and 2008-2012. PSM was positively correlated with tumor category and grade. Ovarian and prostate cancers had the highest PSM prevalence in women and men, respectively. The highest PSM rates for cancers affecting both genders were seen for oral cavity tumors. PSM rates for breast cancer and lung and bronchus cancer in both men and women declined over the study period. PSM increases were seen for bladder, colon and rectum, and kidney and renal pelvis cancers. This large-scale analysis appraises the magnitude of PSM in the United States in order to focus future efforts on improving oncologic surgical care with the goal of optimizing value and improving patient outcomes
Slideflow: Deep Learning for Digital Histopathology with Real-Time Whole-Slide Visualization
Deep learning methods have emerged as powerful tools for analyzing
histopathological images, but current methods are often specialized for
specific domains and software environments, and few open-source options exist
for deploying models in an interactive interface. Experimenting with different
deep learning approaches typically requires switching software libraries and
reprocessing data, reducing the feasibility and practicality of experimenting
with new architectures. We developed a flexible deep learning library for
histopathology called Slideflow, a package which supports a broad array of deep
learning methods for digital pathology and includes a fast whole-slide
interface for deploying trained models. Slideflow includes unique tools for
whole-slide image data processing, efficient stain normalization and
augmentation, weakly-supervised whole-slide classification, uncertainty
quantification, feature generation, feature space analysis, and explainability.
Whole-slide image processing is highly optimized, enabling whole-slide tile
extraction at 40X magnification in 2.5 seconds per slide. The
framework-agnostic data processing pipeline enables rapid experimentation with
new methods built with either Tensorflow or PyTorch, and the graphical user
interface supports real-time visualization of slides, predictions, heatmaps,
and feature space characteristics on a variety of hardware devices, including
ARM-based devices such as the Raspberry Pi
Enhancing the development and approval of acute stroke therapies: Stroke Therapy Academic Industry roundtable
BACKGROUND: Previous Stroke Therapy Academic Industry Roundtable (STAIR) meetings focused on preclinical evidence of drug efficacy and enhancing acute stroke trial design and performance. A fourth (STAIR-IV) was held to discuss relevant issues related to acute stroke drug development and regulatory approval. SUMMARY OF REVIEW: The STAIR-IV meeting had 3 main focus areas. The first topic was novel approaches to statistical design of acute stroke trials and appropriate outcome measures. The second focus was the need for better cooperation among participants in stroke therapy development that may be addressed through a national consortium of stroke trial centers in the United States and elsewhere. Lastly, regulatory issues related to the approval of novel mono and multiple acute stroke therapies were discussed. CONCLUSIONS: The development of additional acute stroke therapies represents a large unmet need with many remaining challenges and also opportunities to incorporate novel approaches to clinical trial design that will lead to regulatory approval. The STAIR-IV meeting explored new concepts of trial methodology and data analysis, initiatives for implementing a US clinical trialist consortium, and pertinent regulatory issues to expedite approval of novel therapies
Tracking and imaging gamma ray experiment (TIGRE) for 1 to 100 MEV gamma ray astronomy
A large international collaboration from the high energy astrophysics community has proposed the Tracking and Imaging Gamma Ray Experiment (TIGRE) for future space observations. TIGRE will image and perform energy spectroscopy measurements on celestial sources of gamma rays in the energy range from 1 to 100 MeV. This has been a difficult energy range experimentally for gamma ray astronomy but is vital for the future considering the recent exciting measurements below 1 and above 100 MeV. TIGRE is both a double scatter Compton and gamma ray pair telescope with direct imaging of individual gamma ray events.
Multiâlayers of Si strip detectors are used as Compton and pair converters CsI(Tl) scintillation detectors are used as a position sensitive calorimeter. Alternatively, thick GE strip detectors may be used for the calorimeter. The Si detectors are able to track electrons and positrons through successive Si layers and measure their directions and energy losses. Compton and pair events are completely reconstructed allowing each event to be imaged on the sky. TIGRE will provide an orderâofâmagnitude improvement in discrete source sensitivity in the 1 to 100 MeV energy range and determine spectra with excellent energy and excellent angular resolutions. Itâs wide fieldâofâview of Ï sr permits observations of the entire sky for extended periods of time over the life of the mission
Elemental abundances of low-mass stars in the young clusters 25 Ori and lambda Ori
Aims. We aim to derive the chemical pattern of the young clusters 25 Orionis
and lambda Orionis through homogeneous and accurate measurements of elemental
abundances. Methods. We present FLAMES/UVES observations of a sample of 14
K-type targets in the 25 Ori and lambda Ori clusters; we measure their radial
velocities, in order to confirm cluster membership. We derive stellar
parameters and abundances of Fe, Na, Al, Si, Ca, Ti, and Ni using the code
MOOG. Results. All the 25 Ori stars are confirmed cluster members without
evidence of binarity; in lambda Ori we identify one non-member and one
candidate single-lined binary star. We find an average metallicity
[Fe/H]=-0.05+/-0.05 for 25 Ori, where the error is the 1sigma standard
deviation from the average. lambda Ori members have a mean iron abundance value
of 0.01+/-0.01. The other elements show close-to-solar ratios and no
star-to-star dispersion. Conclusions. Our results, along with previous
metallicity determinations in the Orion complex, evidence a small but
detectable dispersion in the [Fe/H] distribution of the complex. This appears
to be compatible with large-scale star formation episodes and initial
non-uniformity in the pre-cloud medium. We show that, as expected, the
abundance distribution of star forming regions is consistent with the chemical
pattern of the Galactic thin disk.Comment: Accepted by Astronomy and Astrophysics. 14 pages, 10 figures, 7
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