Light scattering from a magnetically tunable dense random medium with weak dissipation : ferrofluid

We present a semi-phenomenological treatment of light transmission through and its reflection from a ferrofluid, which we regard as a magnetically tunable system of dense random dielectric scatterers with weak dissipation. Partial spatial ordering is introduced by the application of a transverse magnetic field that superimposes a periodic modulation on the dielectric randomess. This introduces Bragg scattering which effectively enhances the scattering due to disorder alone, and thus reduces the elastic mean free path towards Anderson localization. Our theoretical treatment, based on invariant imbedding, gives a simultaneous decrease of transmission and reflection without change of incident linear polarisation as the spatial order is tuned magnetically to the Bragg condition, namely the light wave vector being equal to half the Bragg vector (Q). Our experimental observations are in qualitative agreement with these results. We have also given expressions for the transit (sojourn) time of light and for the light energy stored in the random medium under steady illumination. The ferrofluid thus provides an interesting physical realization of effectively a "Lossy Anderson-Bragg" (LAB) cavity with which to study the effect of the interplay of spatial disorder, partial order and weak dissipation on light transport. Given the current interest in propagation, optical limiting and storage of light in ferrofluids, the present work seems topical

Dynamics of osteoblasts during bone remodeling cycle

Bone is a dynamic connective tissue which adjusts to load variations through continuous bone remodeling, which occurs due to the dynamic behavior of bone cells. Many researchers made attempts in obtaining the dynamic characteristics of osteoblasts and its role in bone remodeling cycle. While making an effort to understand the effects of mechanical stimuli on the osteoblast, certain ambiguity is observed in the past literatures. This paper is to demonstrate the dynamics of osteoblast cells and exhibition of different natural frequencies during its life cycle. Osteoblast is modeled as a frustum of a sphere, considering it as a continuum model. The three prominent parts of an osteoblast, i.e., membrane, cytoplasm and nucleus are considered with reported material properties. Lifespan of an active osteoblast during bone remodeling cycle is considered as 90 days and progressive osteoblast stages are analysed using Ansys. First ten natural frequencies and mode shapes are extracted for nine stages and reported. It is observed that the natural frequencies of a micron sized osteoblast are in the range of kHz. A mathematical relation for the lifespan of an active osteoblast is obtained using curve fitting for fundamental natural frequencies. The natural frequency for exciting an active osteoblast on each particular day during its lifespan can be derived from the relation. This relation can serve as a guiding tool in bioengineering for in vitro bone cell culturing. Results also throw light on the excitation frequency and natural frequency of an osteoblast for proper analysis purpose. The different modes of vibration of osteoblast is identified and reported

Mean platelet volume as short-term follow-up biomarker in children with celiac disease

Objective: To assess the mean platelet volume (MPV) as a short-term follow-up biomarker in celiac disease (CD) and to compare it with anti-tissue transglutaminase antibody (TTGA) assay in Indian children. Material and Methods: Newly diagnosed 35 children aged <12 years who were positive for TTGA and further confirmed by intestinal biopsy with histological Grade 2 and 3 based on modified Marsh Classification were enrolled. TTGA, MPV, and clinical parameters were assessed at enrollment and after 3 months of gluten free diet (GFD). Results: Short stature (94.3%) and diarrhea (80%) were the most common presenting features. 33 (94.3%) children were found to have anemia. MPV reduced significantly from 9.28±1.88 fl to 8.55±1.10 fl after 3 months of GFD, (p<0.001). The mean TTG level reduced from 166.80±59.23 U/ml to 86.45±39.67 U/ml (p<0.001) after 3 months of GFD. Conclusion: MPV is one of the biomarkers that can be used to monitor dietary transgressions in CD in short term

Pulsed Radio Emission from the Fermi-LAT Pulsar J1732-3131: Search and A Possible Detection at 34.5 MHz

We report our search for and a possible detection of periodic radio pulses at 34.5 MHz from the Fermi-LAT pulsar J1732-3131. The candidate detection has been possible in only one of the many sessions of observations made with the low-frequency array at Gauribidanur, India, when the otherwise radio weak pulsar may have apparently brightened many folds. The candidate dispersion measure along the sight-line, based on the broad periodic profiles from about 20 minutes of data, is estimated to be 15.44 +/-0.32 pc/cc. We present the details of our periodic & single-pulse search, and discuss the results and their implications relevant to both, the pulsar and the intervening medium.Comment: 6 pages, 4 figures, 1 table. Accepted for publication in MNRA

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

A gauge model with exact Cabibbo universality

A SUL(3) ⊗ U(1) gauge model is proposed which has exact Cabibbo universality provided a discrete symmetry is imposed. The main departures from the standard sequential model are (i) τ- is an orthoelectron and yet preserves e-μ universality in its decays, (ii) an orthomuon X- violating e-μ universality in its decays is predicted, (iii) the sixth flavor g has charge -1/3

Osmotic myelinolysis: Does extrapontine myelinolysis precede central pontine myelinolysis? Report of two cases and review of literature

Osmotic myelinolysis is an acute, rare, demyelinating process. After the initial description of the condition by Adam and colleagues in 1959, many case series have been published describing the central and extrapontine myelinolysis. Imaging has a definitive role in establishing the diagnosis of osmotic myelinolysis in vivo and diffusion-weighted imaging reveals earliest changes in affected brain parenchyma. We report two cases of patients with proven malignancy who developed extrapontine myelinolysis after treatment for hyponatremia and progressed to central pontine myelinolysis within a week. This was confirmed with magnetic resonance (MR) imaging and clinical assessment. This temporal progression of MR features, especially on diffusion-weighted imaging, from extrapontine to central pontine myelinolysis in osmotic injury has not been described in literature to the best of our knowledge. An early MRI of the brain in suspected/high-risk cases of osmotic myelinolysis may show features of extrapontine myelinolysis in the form of restricted diffusion in bilateral basal ganglia and may serve as a guide for predicting progression, prognosticating and deciding further treatment of pontine myelinolysis. We propose that in a significant number of cases, central pontine myelinolysis may be predicted by doing an early MRI of the brain with diffusion-weighted imaging, when extrapontine symptoms start to develop. This can potentially increase the window period and possibilities for therapeutic intervention and may even help in prevention

Unusual continuous intra-abdominal spread of primary testicular lymphoma along the spermatic cord and gonadal vessels: Report of 2 cases

AbstractPrimary testicular lymphoma (PTL) is an uncommon neoplasm (<5% of all testicular tumors). Testicular lymphoma presents with homogeneous mass, hyperintense on T1-weighted images, and iso-to-hypointense on T2-weighted images with strong diffusion restriction and homogeneous contrast enhancement. Seminoma testis, a close differential due to T2 hypointensity and homogeneousity, can be differentiated by its lower diffusion restriction and younger age group. Involvement of spermatic cord and epididymis is rare with seminoma. Intra-abdominal extension along the gonadal vein is not reported. PTL disseminates to extranodal sites. However, extension of PTL along the spermatic cord and gonadal vein up to the inferior vena cava is a rare phenomenon. We report 2 cases of PTL with involvement of epididymis and spermatic cord and further continuous extension along the gonadal vein up to the inferior vena cava. These findings are very rare and when present may help to differentiate testicular lymphoma from other testicular tumors

Unusual continuous intra-abdominal spread of primary testicular lymphoma along the spermatic cord and gonadal vessels: Report of 2 cases

Primary testicular lymphoma (PTL) is an uncommon neoplasm (<5% of all testicular tumors). Testicular lymphoma presents with homogeneous mass, hyperintense on T1-weighted images, and iso-to-hypointense on T2-weighted images with strong diffusion restriction and homogeneous contrast enhancement. Seminoma testis, a close differential due to T2 hypointensity and homogeneousity, can be differentiated by its lower diffusion restriction and younger age group. Involvement of spermatic cord and epididymis is rare with seminoma. Intra-abdominal extension along the gonadal vein is not reported. PTL disseminates to extranodal sites. However, extension of PTL along the spermatic cord and gonadal vein up to the inferior vena cava is a rare phenomenon. We report 2 cases of PTL with involvement of epididymis and spermatic cord and further continuous extension along the gonadal vein up to the inferior vena cava. These findings are very rare and when present may help to differentiate testicular lymphoma from other testicular tumors