Indiana University

About: Indiana University is a education organization based out in Bloomington, Indiana, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 64480 authors who have published 150058 publications receiving 6392902 citations. The organization is also known as: Indiana University system & indiana.edu.

Large, solution-processable graphene quantum dots as light absorbers for photovoltaics.

Abstract: Graphenes have very attractive properties for photovoltaics. Their tunable bandgap and large optical absorptivity are desirable for efficient light harvesting. Their electronic levels and interfacing with other materials for charge transfer processes can both be tuned with well-developed carbon chemistry. Graphenes have also been shown to have very large charge mobilities, which could be useful for charge collection in solar cells. In addition, they consist of elements abundant on Earth and are environmentally friendly. However, these important properties have not been taken advantage of because graphenes that are large enough to be useful for photovoltaics have extremely poor solubility and have a strong tendency to aggregate into graphite. Here we present a novel solubilization strategy for large graphene nanostructures. It has enabled us to synthesize solution-processable, black graphene quantum dots with uniform size through solution chemistry, and we show that they can be used as sensitizers for sola...

The BCL-6 proto-oncogene controls germinal-centre formation and Th2-type inflammation

Abstract: Structural alterations of the promoter region of the BCL-6 proto-oncogene represent the most frequent genetic alteration associated with non-Hodgkin lymphoma, a malignancy often deriving from germinal-centre B cells. The BCL-6 gene encodes a zinc-finger transcriptional represser normally expressed in both B cells and CD4+ T cells within germinal centres, but its precise function is unknown. We show that mice deficient in BCL-6 displayed normal B-cell, T-cell and lymphoid-organ development but have a selective defect in T-cell-dependent antibody responses. This defect included a complete lack of affinity maturation and was due to the inability of follicular B cells to proliferate and form germinal centres. In addition, BCL-6-deficient mice developed an inflammatory response in multiple organs characterized by infiltrations of eosinophils and IgE-bearing B lymphocytes typical of a Th2-mediated hyperimmune response. Thus, BCL-6 functions as a transcriptional switch that controls germinal centre formation and may also modulate specific T-cell-mediated responses. Altered expression of BCL-6 in lymphoma represents a deregulation of the pathway normally leading to B cell proliferation and germinal centre formation.

The cholinergic system in the pathophysiology and treatment of Alzheimer's disease.

Abstract: Cholinergic synapses are ubiquitous in the human central nervous system. Their high density in the thalamus, striatum, limbic system, and neocortex suggest that cholinergic transmission is likely to be critically important for memory, learning, attention and other higher brain functions. Several lines of research suggest additional roles for cholinergic systems in overall brain homeostasis and plasticity. As such, the brain's cholinergic system occupies a central role in ongoing research related to normal cognition and age-related cognitive decline, including dementias such as Alzheimer's disease. The cholinergic hypothesis of Alzheimer's disease centres on the progressive loss of limbic and neocortical cholinergic innervation. Neurofibrillary degeneration in the basal forebrain is believed to be the primary cause for the dysfunction and death of forebrain cholinergic neurons, giving rise to a widespread presynaptic cholinergic denervation. Cholinesterase inhibitors increase the availability of acetylcholine at synapses in the brain and are one of the few drug therapies that have been proven clinically useful in the treatment of Alzheimer's disease dementia, thus validating the cholinergic system as an important therapeutic target in the disease. This review includes an overview of the role of the cholinergic system in cognition and an updated understanding of how cholinergic deficits in Alzheimer's disease interact with other aspects of disease pathophysiology, including plaques composed of amyloid-β proteins. This review also documents the benefits of cholinergic therapies at various stages of Alzheimer's disease and during long-term follow-up as visualized in novel imaging studies. The weight of the evidence supports the continued value of cholinergic drugs as a standard, cornerstone pharmacological approach in Alzheimer's disease, particularly as we look ahead to future combination therapies that address symptoms as well as disease progression.

Oxidation of the Ediacaran Ocean

Abstract: Oxygenation of the Earth's surface is thought to have occurred in two main steps. The first, about 2,300 million years ago, saw a significant increase in atmospheric and surface ocean oxygen levels and has been widely studied. Much less is known about the second step, which took place around 800–540 million years ago and appears to have been associated with the evolution of complex animals. Now carbon and sulphur isotope records from sediments in the Sultanate of Oman have been used to construct a record of the amount of oxygen in the ocean during the Ediacaran period (635–542 million years ago). The data suggest that there were three distinct stages of oxidation within this period: the second stage involved an increase in oxygen in the deep ocean and appears to have been associated with the evolution of complex animals. Reconstruction of the amount of oxygen in the ocean during the Ediacaran period using carbon- and sulphur-isotope records identifies three distinct stages of oxidation over this interval. Complex animals may have evolved during the second stage, indicating that this event may have played a key role in the evolution of eukaryotic organisms. Oxygenation of the Earth’s surface is increasingly thought to have occurred in two steps. The first step, which occurred ∼2,300 million years (Myr) ago, involved a significant increase in atmospheric oxygen concentrations and oxygenation of the surface ocean1,2. A further increase in atmospheric oxygen appears to have taken place during the late Neoproterozoic period3,4 (∼800–542 Myr ago). This increase may have stimulated the evolution of macroscopic multicellular animals and the subsequent radiation of calcified invertebrates4,5, and may have led to oxygenation of the deep ocean6. However, the nature and timing of Neoproterozoic oxidation remain uncertain. Here we present high-resolution carbon isotope and sulphur isotope records from the Huqf Supergroup, Sultanate of Oman, that cover most of the Ediacaran period (∼635 to ∼548 Myr ago). These records indicate that the ocean became increasingly oxygenated after the end of the Marinoan glaciation, and they allow us to identify three distinct stages of oxidation. When considered in the context of other records from this period7,8,9,10,11,12,13,14,15, our data indicate that certain groups of eukaryotic organisms appeared and diversified during the second and third stages of oxygenation. The second stage corresponds with the Shuram excursion in the carbon isotope record16 and seems to have involved the oxidation of a large reservoir of organic carbon suspended in the deep ocean6, indicating that this event may have had a key role in the evolution of eukaryotic organisms. Our data thus provide new insights into the oxygenation of the Ediacaran ocean and the stepwise restructuring of the carbon6,16,17 and sulphur cycles3,18,19 that occurred during this significant period of Earth’s history.

Bilateral orchiectomy with or without flutamide for metastatic prostate cancer

Abstract: Background Combined androgen blockade for the treatment of metastatic prostate cancer consists of an antiandrogen drug plus castration. In a previous trial, we found that adding the antiandrogen flutamide to leuprolide acetate (a synthetic gonadotropin-releasing hormone that results in medical ablation of testicular function) significantly improved survival as compared with that achieved with placebo plus leuprolide acetate. In the current trial, we compared flutamide plus bilateral orchiectomy with placebo plus orchiectomy. Methods We randomly assigned patients who had never received antiandrogen therapy and who had distant metastases from adenocarcinoma of the prostate to treatment with bilateral orchiectomy and either flutamide or placebo. Patients were stratified according to the extent of disease and according to performance status. Results Of the 1387 patients who were enrolled in the trial, 700 were randomly assigned to the flutamide group and 687 to the placebo group. Overall, the incidence of tox...