1,164 research outputs found
Charge Delocalization in Self-Assembled Mixed-Valence Aromatic Cation Radicals
The spontaneous assembly of aromatic cation radicals (D+•) with their neutral counterpart (D) affords dimer cation radicals (D2+•). The intermolecular dimeric cation radicals are readily characterized by the appearance of an intervalence charge-resonance transition in the NIR region of their electronic spectra and by ESR spectroscopy. The X-ray crystal structure analysis and DFT calculations of a representative dimer cation radical (i.e., the octamethylbiphenylene dimer cation radical) have established that a hole (or single positive charge) is completely delocalized over both aromatic moieties. The energetics and the geometrical considerations for the formation of dimer cation radicals is deliberated with the aid of a series of cyclophane-like bichromophoric donors with drastically varied interplanar angles between the cofacially arranged aryl moieties. X-ray crystallography of a number of mixed-valence cation radicals derived from monochromophoric benzenoid donors established that they generally assemble in 1D stacks in the solid state. However, the use of polychromophoric intervalence cation radicals, where a single charge is effectively delocalized among all of the chromophores, can lead to higher-order assemblies with potential applications in long-range charge transport. As a proof of concept, we show that a single charge in the cation radical of a triptycene derivative is evenly distributed on all three benzenoid rings and this triptycene cation radical forms a 2D electronically coupled assembly, as established by X-ray crystallography
Status of soluble vascular cell adhesion molecule-1 in knee osteoarthritis among type 2-diabetic postmenopausal women
Background: Knee osteoarthritis is the most common form of joint disorder and a leading cause of pain and functional disability among elderly female population. Type 2-diabetes is frequently reported comorbidity in elderly female patients with knee osteoarthritis. VCAM-1 is emerging as a strong and independent predictor for severe osteoarthritis. VCAM-1 is an inducible cell surface sialo glycoprotein and mediates heterotypic cellular aggregation. Therefore, the aim of this study is to assess the role of soluble vascular cell adhesion molecule-1 at the onset of knee osteoarthritis among type 2 diabetic postmenopausal women.Methods: The present study includes 100 type 2-diabetic female subjects of age above 50 years as cases and 100 normal healthy female age matched individuals as controls. Osteoarthritis of knee was ascertained using the American college of rheumatology classification criteria. Serum soluble VCAM-1 concentration was measured by ELISA method in all 200 subjects. Biochemical parameters-Fasting blood sugar and lipid profile were measured using Mind ray BS-400 and HbA1c was measured by turbidimetric immunoassay method. Statistical analysis was made by student independent sample t-test. Correlation was determined by using spearman’s rank correlation coefficient.Results: Serum level of soluble VCAM-1 was found statistically highly significant (p<0.001) in type 2 diabetic postmenopausal women having early stage of knee osteoarthritis as compared to control healthy subjects. The mean levels of fasting blood sugar, HbA1c, total cholesterol, TG, LDL-C and VLDL-C were also found significantly increased while HDL-C was found significantly decreased in cases as compared to controls.Conclusions: The increased level of soluble VCAM-1 in type 2 diabetic subjects shows active inflammation or cartilage damage. Therefore, it can be used as an early biomarker for osteoarthritis among type 2 diabetic postmenopausal women
Dynamical evolution and leading order gravitational wave emission of Riemann-S binaries
An approximate strategy for studying the evolution of binary systems of
extended objects is introduced. The stars are assumed to be polytropic
ellipsoids. The surfaces of constant density maintain their ellipsoidal shape
during the time evolution. The equations of hydrodynamics then reduce to a
system of ordinary differential equations for the internal velocities, the
principal axes of the stars and the orbital parameters. The equations of motion
are given within Lagrangian and Hamiltonian formalism. The special case when
both stars are axially symmetric fluid configurations is considered. Leading
order gravitational radiation reaction is incorporated, where the quasi-static
approximation is applied to the internal degrees of freedom of the stars. The
influence of the stellar parameters, in particular the influence of the
polytropic index , on the leading order gravitational waveforms is studied.Comment: 31 pages, 7 figures, typos correcte
Characterization of heterosis and genomic prediction‐based establishment of heterotic patterns for developing better hybrids in pigeonpea
Whole-genome resequencing (WGRS) of 396 lines, consisting of 104 hybrid parental lines and 292 germplasm lines, were used to study the molecular basis of mid-parent heterosis (MPH) and to identify complementary heterotic patterns in pigeonpea [Cajanus cajan (L.) Millsp.] hybrids. The lines and hybrids were assessed for yield and yield-related traits in multiple environments. Our analysis showed positive MPH values in 78.6% of hybrids, confirming the potential of hybrid breeding in pigeonpea. By using genome-wide prediction and association mapping approaches, we identified 129 single nucleotide polymorphisms and 52 copy number variations with significant heterotic effects and also established a high-yielding heterotic pattern in pigeonpea. In summary, our study highlights the role of WGRS data in the study and use of heterosis in crops where hybrid breeding is expected to boost selection gain in order to ensure global food security
Deep Learning versus Classical Regression for Brain Tumor Patient Survival Prediction
Deep learning for regression tasks on medical imaging data has shown
promising results. However, compared to other approaches, their power is
strongly linked to the dataset size. In this study, we evaluate
3D-convolutional neural networks (CNNs) and classical regression methods with
hand-crafted features for survival time regression of patients with high grade
brain tumors. The tested CNNs for regression showed promising but unstable
results. The best performing deep learning approach reached an accuracy of
51.5% on held-out samples of the training set. All tested deep learning
experiments were outperformed by a Support Vector Classifier (SVC) using 30
radiomic features. The investigated features included intensity, shape,
location and deep features. The submitted method to the BraTS 2018 survival
prediction challenge is an ensemble of SVCs, which reached a cross-validated
accuracy of 72.2% on the BraTS 2018 training set, 57.1% on the validation set,
and 42.9% on the testing set. The results suggest that more training data is
necessary for a stable performance of a CNN model for direct regression from
magnetic resonance images, and that non-imaging clinical patient information is
crucial along with imaging information.Comment: Contribution to The International Multimodal Brain Tumor Segmentation
(BraTS) Challenge 2018, survival prediction tas
White Dwarfs Near Black Holes: A New Paradigm for Type I Supernovae
We present calculations indicating the possibility of a new class of Type I
supernovae. In this new paradigm relativistic terms enhance the self gravity of
a carbon-oxygen white dwarf as it passes or orbits near a black hole. This
relativistic compression can cause the central density to exceed the threshold
for pycnonuclear reactions so that athermonuclear runaway ensues. We consider
three possible environments: 1) white dwarfs orbiting a low-mass black hole; 2)
white dwarfs encountering a massive black hole in a dense globular cluster; and
3) white dwarfs passing a supermassive black hole in a dense galactic core. We
estimate the rate at which such events could occur out to a redshift of z = 1.
Event rates are estimated to be significantly less than the rate of normal Type
Ia supernovae for all three classes. Nevertheless, such events may be frequent
enough to warrant a search for this new class of supernova. We propose several
observable signatures which might be used to identify this type of event and
speculate that such an event might have produced the observed
"mixed-morphology" Sgr A East supernova remnant in the Galactic core.Comment: Accepted for Publication in The Astrophysical Journa
Recruitment of ethnic minority patients to a cardiac rehabilitation trial: The Birmingham Rehabilitation Uptake Maximisation (BRUM) study [ISRCTN72884263]
Background: Concerns have been raised about low participation rates of people from minority ethnic groups
in clinical trials. However, the evidence is unclear as many studies do not report the ethnicity of participants and
there is insufficient information about the reasons for ineligibility by ethnic group. Where there are data, there
remains the key question as to whether ethnic minorities more likely to be ineligible (e.g. due to language) or
decline to participate. We have addressed these questions in relation to the Birmingham Rehabilitation Uptake
Maximisation (BRUM) study, a randomized controlled trial (RCT) comparing a home-based with a hospital-based
cardiac rehabilitation programme in a multi-ethnic population in the UK.
Methods: Analysis of the ethnicity, age and sex of presenting and recruited subjects for a trial of cardiac
rehabilitation in the West-Midlands, UK.
Participants: 1997 patients presenting post-myocardial infarction, percutaneous transluminal coronary angioplasty
or coronary artery bypass graft surgery.
Data collected: exclusion rates, reasons for exclusion and reasons for declining to participate in the trial by ethnic
group.
Results: Significantly more patients of South Asian ethnicity were excluded (52% of 'South Asian' v 36% 'White
European' and 36% 'Other', p < 0.001). This difference in eligibility was primarily due to exclusion on the basis of
language (i.e. the inability to speak English or Punjabi). Of those eligible, similar proportions were recruited from
the different ethnic groups (white, South Asian and other). There was a marked difference in eligibility between
people of Indian, Pakistani or Bangladeshi origin
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Measures of multiple deprivation and visual field loss in glaucoma clinics in England: lessons from big data
Background/Objectives
To examine the association between multiple deprivation with late diagnosis and rapid worsening of glaucoma in patients in English hospital eye services (HES).
Methods
602,439 visual fields (VFs) were extracted from five regionally different glaucoma clinics in England. Mean Deviation (MD) worse than −12 dB was used as a surrogate definition for advanced VF loss at diagnosis in patients with ≥2 reliable VF records. MD loss worse than -1 dB per year was used to define rapid VF progression in patients with ≥6 VFs. Patient data were stratified into deciles of the Index of Multiple Deprivation (IMD) from residential postcodes.
Results
There was an association between IMD and advanced VF loss at diagnosis in 44,956 patients with 18% (293/1608) and 11% (771/6929) in the most and least deprived IMD decile, respectively. Age-corrected odds ratio (OR) for having advanced VF loss at entry into HES was 1.42 (95% confidence interval [CI] 1.21–1.67) and 0.75 (95% CI: 0.66–0.85) in the most and least deprived IMD decile respectively (reference = fifth decile). In 15,094 patients with follow up data (median [interquartile range] of 6.9 [4.5, 10.0] years), the proportion having rapid VF progression did not differ across the IMD spectrum.
Conclusion
Large-scale VF data from clinics indicates that glaucoma severity at presentation to English HES is associated with levels of multiple deprivation. We found no evidence to suggest likelihood of having rapid VF progression during follow-up is associated with IMD; this hints at equity of glaucoma care and outcomes once patients are in English HES
Stalking influenza by vaccination with pre-fusion headless HA mini-stem.
Inaccuracies in prediction of circulating viral strain genotypes and the possibility of novel reassortants causing a pandemic outbreak necessitate the development of an anti-influenza vaccine with increased breadth of protection and potential for rapid production and deployment. The hemagglutinin (HA) stem is a promising target for universal influenza vaccine as stem-specific antibodies have the potential to be broadly cross-reactive towards different HA subtypes. Here, we report the design of a bacterially expressed polypeptide that mimics a H5 HA stem by protein minimization to focus the antibody response towards the HA stem. The HA mini-stem folds as a trimer mimicking the HA prefusion conformation. It is resistant to thermal/chemical stress, and it binds to conformation-specific, HA stem-directed broadly neutralizing antibodies with high affinity. Mice vaccinated with the group 1 HA mini-stems are protected from morbidity and mortality against lethal challenge by both group 1 (H5 and H1) and group 2 (H3) influenza viruses, the first report of cross-group protection. Passive transfer of immune serum demonstrates the protection is mediated by stem-specific antibodies. Furthermore, antibodies indudced by these HA stems have broad HA reactivity, yet they do not have antibody-dependent enhancement activity
Operations perspective to competency-based medical education: Experiences of IUPS-ICMR Physiology Education Workshop series (2018-2019) conducted in India
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