289 research outputs found
Negative pressure pulmonary edema - a life-threatening condition in an eye care setting: a case report
Ferroelectricity induced by interatomic magnetic exchange interaction
Multiferroics, where two or more ferroic order parameters coexist, is one of
the hottest fields in condensed matter physics and materials science[1-9].
However, the coexistence of magnetism and conventional ferroelectricity is
physically unfavoured[10]. Recently several remedies have been proposed, e.g.,
improper ferroelectricity induced by specific magnetic[6] or charge orders[2].
Guiding by these theories, currently most research is focused on frustrated
magnets, which usually have complicated magnetic structure and low magnetic
ordering temperature, consequently far from the practical application. Simple
collinear magnets, which can have high magnetic transition temperature, have
never been considered seriously as the candidates for multiferroics. Here, we
argue that actually simple interatomic magnetic exchange interaction already
contains a driving force for ferroelectricity, thus providing a new microscopic
mechanism for the coexistence and strong coupling between ferroelectricity and
magnetism. We demonstrate this mechanism by showing that even the simplest
antiferromagnetic (AFM) insulator MnO, can display a magnetically induced
ferroelectricity under a biaxial strain
First-principles design and subsequent synthesis of a material to search for the permanent electric dipole moment of the electron
We describe the first-principles design and subsequent synthesis of a new
material with the specific functionalities required for a solid-state-based
search for the permanent electric dipole moment of the electron. We show
computationally that perovskite-structure europium barium titanate should
exhibit the required large and pressure-dependent ferroelectric polarization,
local magnetic moments, and absence of magnetic ordering even at liquid helium
temperature. Subsequent synthesis and characterization of
EuBaTiO ceramics confirm the predicted desirable
properties.Comment: Nature Materials, in pres
Anemia and growth failure among HIV-infected children in India: a retrospective analysis
<p>Abstract</p> <p>Background</p> <p>Anemia and poor nutrition have been previously described as independent risk factors for death among HIV-infected children. We sought to describe nutritional status, anemia burden and HIV disease correlates among infected children in India.</p> <p>Methods</p> <p>We analyzed retrospective data from 248 HIV-infected children aged 1–12 years attending three outpatient clinics in South India (2004–2006). Standard WHO definitions were used for anemia, HIV staging and growth parameters. Statistical analysis included chi square, t tests, univariate and multivariate logistic regression analyses.</p> <p>Results</p> <p>The overall prevalence of anemia (defined as hemoglobin < 11 gm/dL) was 66%, and 8% had severe anemia (Hb < 7 gm/dL). The proportion of underweight and stunted children in the population was 55% and 46% respectively. Independent risk factors of anemia by multivariate analysis included the pre-school age group (age younger than 6 years) (OR: 2.87; 95% CI: 1.45, 5.70; p < 0.01), rural residence (OR: 12.04; 95% CI: 5.64, 26.00; p < 0.01), advanced HIV disease stage (OR: 6.95; 95% CI: 3.06, 15.79; p < 0.01) and presence of stunting (Height-for-age Z Score < -2) (OR: 3.24; 95% CI: 1.65, 6.35; p < 0.01). Use of iron/multivitamin supplementation was protective against risk of anemia (OR: 0.44; 95% CI: 0.22, 0.90; p = 0.03). Pulmonary tuberculosis was an independent risk factor in multivariate analysis (OR: 3.36; 95% CI: 1.43, 7.89; p < 0.01) when correlated variables such as HIV disease stage and severe immunodeficiency, and nutritional supplement use were not included. Use of antiretroviral therapy (ART) was associated with a reduced risk of anemia (OR: 0.29; 95% CI: 0.16, 0.53; p < 0.01). No significant association was found between anemia and gender, cotrimoxazole, or ART type (zidovudine versus stavudine).</p> <p>Conclusion</p> <p>The high prevalence and strong interrelationship of anemia and poor nutrition among HIV-infected children in India, particularly those living in rural areas underscores the need for incorporating targeted nutritional interventions during national scale up of care, support and treatment among HIV-infected children.</p
A Topical Microbicide Gel Formulation of CCR5 Antagonist Maraviroc Prevents HIV-1 Vaginal Transmission in Humanized RAG-hu Mice
For prevention of HIV infection many currently licensed anti-HIV drugs and new ones in the pipeline show potential as topically applied microbicides. While macaque models have been the gold standard for in vivo microbicide testing, they are expensive and sufficient numbers are not available. Therefore, a small animal model that facilitates rapid evaluation of potential candidates for their preliminary efficacy is urgently needed in the microbicide field. We previously demonstrated that RAG-hu humanized mouse model permits HIV-1 mucosal transmission via both vaginal and rectal routes and that oral pre-exposure chemo-prophylactic strategies could be tested in this system. Here in these proof-of-concept studies, we extended this system for topical microbicide testing using HIV-1 as the challenge virus. Maraviroc, a clinically approved CCR5 inhibitor drug for HIV treatment, was formulated as a microbicide gel at 5 mM concentration in 2.2% hydroxyl ethyl cellulose. Female RAG-hu mice were challenged vaginally with HIV-1 an hour after intravaginal application of the maraviroc gel. Our results showed that maraviroc gel treated mice were fully protected against vaginal HIV-1 challenge in contrast to placebo gel treated mice which all became infected. These findings highlight the utility of the humanized mouse models for microbicide testing and, together with the recent data from macaque studies, suggest that maraviroc is a promising candidate for future microbicide clinical trials in the field
Inheritance and identification of molecular markers associated with spot blotch (Cochliobolus sativus L.) resistance through microsatellites analysis in barley
Oral Pre-Exposure Prophylaxis by Anti-Retrovirals Raltegravir and Maraviroc Protects against HIV-1 Vaginal Transmission in a Humanized Mouse Model
Sexual HIV-1 transmission by vaginal route is the most predominant mode of viral transmission, resulting in millions of new infections every year. In the absence of an effective vaccine, there is an urgent need to develop other alternative methods of pre-exposure prophylaxis (PrEP). Many novel drugs that are currently approved for clinical use also show great potential to prevent viral sexual transmission when administered systemically. A small animal model that permits rapid preclinical evaluation of potential candidates for their systemic PrEP efficacy will greatly enhance progress in this area of investigation. We have previously shown that RAG-hu humanized mouse model permits HIV-1 mucosal transmission via both vaginal and rectal routes and displays CD4 T cell loss typical to that seen in the human. Thus far systemic PrEP studies have been primarily limited to RT inhibitors exemplified by tenofovir and emtricitabine. In these proof-of-concept studies we evaluated two new classes of clinically approved drugs with different modes of action namely, an integrase inhibitor raltegravir and a CCR5 inhibitor maraviroc as potential systemically administered chemo-prophylactics. Our results showed that oral administration of either of these drugs fully protects against vaginal HIV-1 challenge in the RAG-hu mouse model. Based on these results both these drugs show great promise for further development as orally administered PrEPs
Pyranopyrazolotacrines as nonneurotoxic, Aβ-anti-aggregating and neuroprotective agents for Alzheimer's disease
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