1,542 research outputs found
Automated Biochemical, Morphological, and Organizational Assessment of Precancerous Changes from Endogenous Two-Photon Fluorescence Images
Multi-photon fluorescence microscopy techniques allow for non-invasive interrogation of live samples in their native environment. These methods are particularly appealing for identifying pre-cancers because they are sensitive to the early changes that occur on the microscopic scale and can provide additional information not available using conventional screening techniques.In this study, we developed novel automated approaches, which can be employed for the real-time analysis of two-photon fluorescence images, to non-invasively discriminate between normal and pre-cancerous/HPV-immortalized engineered tissues by concurrently assessing metabolic activity, morphology, organization, and keratin localization. Specifically, we found that the metabolic activity was significantly enhanced and more uniform throughout the depths of the HPV-immortalized epithelia, based on our extraction of the NADH and FAD fluorescence contributions. Furthermore, we were able to separate the keratin contribution from metabolic enzymes to improve the redox estimates and to use the keratin localization as a means to discriminate between tissue types. To assess morphology and organization, Fourier-based, power spectral density (PSD) approaches were employed. The nuclear size distribution throughout the epithelial depths was quantified by evaluating the variance of the corresponding spatial frequencies, which was found to be greater in the normal tissue compared to the HPV-immortalized tissues. The PSD was also used to calculate the Hurst parameter to identify the level of organization in the tissues, assuming a fractal model for the fluorescence intensity fluctuations within a field. We found the range of organization was greater in the normal tissue and closely related to the level of differentiation.A wealth of complementary morphological, biochemical and organizational tissue parameters can be extracted from high resolution images that are acquired based entirely on endogenous sources of contrast. They are promising diagnostic parameters for the non-invasive identification of early cancerous changes and could improve significantly diagnosis and treatment for numerous patients
Electronic states and nature of bonding of the molecule PdGe by all electron ab initio HF–CI calculations and mass spectrometric equilibrium experiments
Electronic states and nature of bonding of the molecule NiGe by all electron ab initio Hartree–Fock (HF) and configuration interaction (CI) calculations and mass spectrometric equilibrium experiments
Electronic states and nature of bonding in the molecule YC by all electron ab initio multiconfiguration self-consistent-field calculations and mass spectrometric equilibrium experiments
Prevalence of depression and anxiety among participants with glaucoma in a population-based cohort study : the Gutenberg Health Study
Background
To investigate the prevalence of depression and anxiety among subjects with self-reported glaucoma and the association between self-reported glaucoma and depression respectively anxiety in a European cohort.
Methods
A study sample of 14,657 participants aged 35 to 74 years was investigated in a population-based cohort study. All participants reported presence or absence of glaucoma. Ophthalmological examinations were carried out in all participants and demographic and disease related information were obtained by interview. Depression was assessed with the Patient Health Questionnaire (PHQ-9), and generalized anxiety with the two screening items (GAD-2) of the short form of the GAD-7 (Generalized Anxiety Disorder-7 Scale). Prevalence of depression and generalized anxiety were investigated for subjects with and without self-reported glaucoma. Logistic regression analyses with depression, respectively anxiety as dependent variable and self-reported glaucoma as independent variable were conducted and adjusted for socio-demographic factors, systemic comorbidities (arterial hypertension, myocardial infarction, stroke, diabetes mellitus, chronic obstructive pulmonary disease, cancer), ocular diseases (cataract, macular degeneration, corneal diseases, diabetic retinopathy), visual acuity, intraocular pressure, antiglaucoma eye drops (sympathomimetics, parasympathomimetics, carbonic anhydrase inhibitors, beta-blockers, prostaglandins) and general health status.
Results
293 participants (49.5% female) reported having glaucoma. Prevalence of depression among participants with and without self-reported glaucoma was 6.6% (95%-CI 4.1–10.3) respectively 7.7% (95%-CI 7.3–8.2), and for anxiety 5.3% (95%-CI 3.1–8.7) respectively 6.6% (95%-CI 6.2–7.1). Glaucoma was not associated with depression (Odds ratio 1.10, 95%-CI 0.50–2.38, p = 0.80) or anxiety (1.48, 95%-CI 0.63–3.30, p = 0.35) after adjustment for socio-demographic factors, ocular/systemic diseases, ocular parameters, antiglaucoma drugs and general health status. A restriction to self-reported glaucoma cases either taking topical antiglaucoma medications or having a history of glaucoma surgery did not alter the result.
Conclusions
This is the first study analyzing both depression and anxiety among glaucoma patients in a European cohort. Subjects with and without self-reported glaucoma had a similar prevalence of depression and anxiety in our population-based sample. Self-reported glaucoma was not associated with depression or anxiety. A lack of a burden of depressive symptoms may result from recruitment from a population-based sample as compared to previous study groups predominantly recruited from tertiary care hospitals
Observation of ultrafast solid-density plasma dynamics using femtosecond X-ray pulses from a free-electron laser
The complex physics of the interaction between short pulse high intensity
lasers and solids is so far hardly accessible by experiments. As a result of
missing experimental capabilities to probe the complex electron dynamics and
competing instabilities, this impedes the development of compact laser-based
next generation secondary radiation sources, e.g. for tumor therapy
[Bulanov2002,ledingham2007], laboratory-astrophysics
[Remington1999,Bulanov2015], and fusion [Tabak2014]. At present, the
fundamental plasma dynamics that occur at the nanometer and femtosecond scales
during the laser-solid interaction can only be elucidated by simulations. Here
we show experimentally that small angle X-ray scattering of femtosecond X-ray
free-electron laser pulses facilitates new capabilities for direct in-situ
characterization of intense short-pulse laser plasma interaction at solid
density that allows simultaneous nanometer spatial and femtosecond temporal
resolution, directly verifying numerical simulations of the electron density
dynamics during the short pulse high intensity laser irradiation of a solid
density target. For laser-driven grating targets, we measure the solid density
plasma expansion and observe the generation of a transient grating structure in
front of the pre-inscribed grating, due to plasma expansion, which is an
hitherto unknown effect. We expect that our results will pave the way for novel
time-resolved studies, guiding the development of future laser-driven particle
and photon sources from solid targets
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Observation of Ultrafast Solid-Density Plasma Dynamics Using Femtosecond X-Ray Pulses from a Free-Electron Laser
The complex physics of the interaction between short-pulse ultrahigh-intensity lasers and solids is so far difficult to access experimentally, and the development of compact laser-based next-generation secondary radiation sources, e.g., for tumor therapy, laboratory astrophysics, and fusion, is hindered by the lack of diagnostic capabilities to probe the complex electron dynamics and competing instabilities. At present, the fundamental plasma dynamics that occur at the nanometer and femtosecond scales during the laser-solid interaction can only be elucidated by simulations. Here we show experimentally that small-angle x-ray scattering of femtosecond x-ray free-electron laser pulses facilitates new capabilities for direct in situ characterization of intense short-pulse laser-plasma interactions at solid density that allows simultaneous nanometer spatial and femtosecond temporal resolution, directly verifying numerical simulations of the electron density dynamics during the short-pulse high-intensity laser irradiation of a solid density target. For laser-driven grating targets, we measure the solid density plasma expansion and observe the generation of a transient grating structure in front of the preinscribed grating, due to plasma expansion. The density maxima are interleaved, forming a double frequency grating in x-ray free-electron laser projection for a short time, which is a hitherto unknown effect. We expect that our results will pave the way for novel time-resolved studies, guiding the development of future laser-driven particle and photon sources from solid targets
Rationale and design of the MULTISTARS AMI Trial: a randomized comparison of immediate versus staged complete revascularization in patients with ST-segment elevation myocardial infarction and multivessel disease
Background:
About half of patients with acute ST-segment elevation myocardial infarction (STEMI) present with multivessel coronary artery disease (MVD). Recent evidence supports complete revascularization in these patients. However, optimal timing of non-culprit lesion revascularization in STEMI patients is unknown because dedicated randomized trials on this topic are lacking.
Study design:
The MULTISTARS AMI trial is a prospective, international, multicenter, randomized, two-arm, open-label study planning to enroll at least 840 patients. It is designed to investigate whether immediate complete revascularization is non-inferior to staged (within 19-45 days) complete revascularization in patients in stable hemodynamic conditions presenting with STEMI and MVD and undergoing primary percutaneous coronary intervention (PCI). After successful primary PCI of the culprit artery, patients are randomized in a 1:1 ratio to immediate or staged complete revascularization. The primary endpoint is a composite of all-cause death, non-fatal myocardial infarction, ischemia-driven revascularization, hospitalization for heart failure, and stroke at 1 year.
Conclusions:
The MULTISTARS AMI trial tests the hypothesis that immediate complete revascularization is non-inferior to staged complete revascularization in stable patients with STEMI and MVD
Visualizing Ultrafast Kinetic Instabilities in Laser-Driven Solids using X-ray Scattering
Ultra-intense lasers that ionize and accelerate electrons in solids to near
the speed of light can lead to kinetic instabilities that alter the laser
absorption and subsequent electron transport, isochoric heating, and ion
acceleration. These instabilities can be difficult to characterize, but a novel
approach using X-ray scattering at keV energies allows for their visualization
with femtosecond temporal resolution on the few nanometer mesoscale. Our
experiments on laser-driven flat silicon membranes show the development of
structure with a dominant scale of ~60\unit{nm} in the plane of the laser
axis and laser polarization, and ~95\unit{nm} in the vertical direction with
a growth rate faster than . Combining the XFEL experiments
with simulations provides a complete picture of the structural evolution of
ultra-fast laser-induced instability development, indicating the excitation of
surface plasmons and the growth of a new type of filamentation instability.
These findings provide new insight into the ultra-fast instability processes in
solids under extreme conditions at the nanometer level with important
implications for inertial confinement fusion and laboratory astrophysics
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