3,422 research outputs found
Current and evolving approaches for improving the oral permeability of BCS Class III or analogous molecules
The Biopharmaceutics Classification System (BCS) classifies pharmaceutical compounds based on their aqueous solubility and intestinal permeability. The BCS Class III compounds are hydrophilic molecules (high aqueous solubility) with low permeability across the biological membranes. While these compounds are pharmacologically effective, poor absorption due to low permeability becomes the rate-limiting step in achieving adequate bioavailability. Several approaches have been explored and utilized for improving the permeability profiles of these compounds. The approaches include traditional methods such as prodrugs, permeation enhancers, ion-pairing, etc., as well as relatively modern approaches such as nanoencapsulation and nanosizing. The most recent approaches include a combination/hybridization of one or more traditional approaches to improve drug permeability. While some of these approaches have been extremely successful, i.e. drug products utilizing the approach have progressed through the USFDA approval for marketing; others require further investigation to be applicable. This article discusses the commonly studied approaches for improving the permeability of BCS Class III compounds
Spread of activation and deactivation in the brain: Does age matter?
Cross-sectional aging fMRI results are sometimes difficult to interpret, as standard measures of activation and deactivation may confound variations in signal amplitude and spread, which however may be differentially affected by age-related changes in various anatomical and physiological factors. To disentangle these two types of measures, here we propose a novel method to obtain independent estimates of the peak amplitude and spread of the BOLD signal in areas activated (task-positive) and deactivated (task-negative) by a Sternberg task, in 14 younger and 28 older adults. The peak measures indicated that, compared to younger adults, older adults had increased activation of the task-positive network, but similar levels of deactivation in the task-negative network. Measures of signal spread revealed that older adults had an increased spread of activation in task-positive areas, but a starkly reduced spread of deactivation in task-negative areas. These effects were consistent across regions within each network. Further, there was greater variability in the anatomical localization of peak points in older adults, leading to reduced cross-subject overlap. These results reveal factors that may confound the interpretation of studies of aging. Additionally, spread measures may be linked to local connectivity phenomena and could be particularly useful to analyze age-related deactivation patterns, complementing the results obtained with standard peak and ROI analyses
Control of RelB during dendritic cell activation integrates canonical and noncanonical NF-κB pathways.
The NF-κB protein RelB controls dendritic cell (DC) maturation and may be targeted therapeutically to manipulate T cell responses in disease. Here we report that RelB promoted DC activation not as the expected RelB-p52 effector of the noncanonical NF-κB pathway, but as a RelB-p50 dimer regulated by canonical IκBs, IκBα and IκBɛ. IκB control of RelB minimized spontaneous maturation but enabled rapid pathogen-responsive maturation. Computational modeling of the NF-κB signaling module identified control points of this unexpected cell type-specific regulation. Fibroblasts that we engineered accordingly showed DC-like RelB control. Canonical pathway control of RelB regulated pathogen-responsive gene expression programs. This work illustrates the potential utility of systems analyses in guiding the development of combination therapeutics for modulating DC-dependent T cell responses
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Loss of androgen signaling in mesenchymal sonic hedgehog responsive cells diminishes prostate development, growth, and regeneration.
Prostate embryonic development, pubertal and adult growth, maintenance, and regeneration are regulated through androgen signaling-mediated mesenchymal-epithelial interactions. Specifically, the essential role of mesenchymal androgen signaling in the development of prostate epithelium has been observed for over 30 years. However, the identity of the mesenchymal cells responsible for this paracrine regulation and related mechanisms are still unknown. Here, we provide the first demonstration of an indispensable role of the androgen receptor (AR) in sonic hedgehog (SHH) responsive Gli1-expressing cells, in regulating prostate development, growth, and regeneration. Selective deletion of AR expression in Gli1-expressing cells during embryogenesis disrupts prostatic budding and impairs prostate development and formation. Tissue recombination assays showed that urogenital mesenchyme (UGM) containing AR-deficient mesenchymal Gli1-expressing cells combined with wildtype urogenital epithelium (UGE) failed to develop normal prostate tissue in the presence of androgens, revealing the decisive role of AR in mesenchymal SHH responsive cells in prostate development. Prepubescent deletion of AR expression in Gli1-expressing cells resulted in severe impairment of androgen-induced prostate growth and regeneration. RNA-sequencing analysis showed significant alterations in signaling pathways related to prostate development, stem cells, and organ morphogenesis in AR-deficient Gli1-expressing cells. Among these altered pathways, the transforming growth factor β1 (TGFβ1) pathway was up-regulated in AR-deficient Gli1-expressing cells. We further demonstrated the activation of TGFβ1 signaling in AR-deleted prostatic Gli1-expressing cells, which inhibits prostate epithelium growth through paracrine regulation. These data demonstrate a novel role of the AR in the Gli1-expressing cellular niche for regulating prostatic cell fate, morphogenesis, and renewal, and elucidate the mechanism by which mesenchymal androgen-signaling through SHH-responsive cells elicits the growth and regeneration of prostate epithelium
Solid state dye sensitized solar cells applying conducting organic polymers as hole conductors
Solid-state dye sensitized solar cells (SSDSCs) applying mesoporous TiO electrodes sensitized with Ru complex dye Z907 and conducting organic polymers as the hole transport material (HTM) are prepared. We employ the in-situ photo-electrochemically polymerization technique (PEP)[1-3] in order to obtain, in a single step, the conducting organic polymer on the TiO /Dye electrode. We developed a modification of reported method [2] which allows the polymer poly(3,4-ethylenedioxythiophene) (PEDOT) by different electrochemical techniques applying constant-voltage and constant-current methods. Polymer morphology and its influence on solar cell performance were studied. Overall conversion efficiency above 2% (AM 1.5, 100 mW cm) was obtained
Branching Rules for Supercuspidal Representations of SL_2(k)
The restriction of a supercuspidal representation of SL_2(k), for k a local
nonarchimedean field, to a maximal compact subgroup decomposes as a
multiplicity-free direct sum of irreducible representations. We explicitly
describe this decomposition in the case that the residual characteristic is
odd, and determine how the spectrum of this decomposition varies as a function
of the parameters describing the supercuspidal representation.Comment: 30 pages; minor reorganization to previous version. Accepted to
Journal of Algebr
SUQL: Conversational Search over Structured and Unstructured Data with Large Language Models
While most conversational agents are grounded on either free-text or
structured knowledge, many knowledge corpora consist of hybrid sources. This
paper presents the first conversational agent that supports the full generality
of hybrid data access for large knowledge corpora, through a language we
developed called SUQL (Structured and Unstructured Query Language).
Specifically, SUQL extends SQL with free-text primitives (summary and answer),
so information retrieval can be composed with structured data accesses
arbitrarily in a formal, succinct, precise, and interpretable notation. With
SUQL, we propose the first semantic parser, an LLM with in-context learning,
that can handle hybrid data sources.
Our in-context learning-based approach, when applied to the HybridQA dataset,
comes within 8.9% exact match and 7.1% F1 of the SOTA, which was trained on 62K
data samples. More significantly, unlike previous approaches, our technique is
applicable to large databases and free-text corpora. We introduce a dataset
consisting of crowdsourced questions and conversations on Yelp, a large, real
restaurant knowledge base with structured and unstructured data. We show that
our few-shot conversational agent based on SUQL finds an entity satisfying all
user requirements 90.3% of the time, compared to 63.4% for a baseline based on
linearization
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