191 research outputs found

    Low-Density Parity-Check Codes for Nonergodic Block-Fading Channels

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    We solve the problem of designing powerful low-density parity-check (LDPC) codes with iterative decoding for the block-fading channel. We first study the case of maximum-likelihood decoding, and show that the design criterion is rather straightforward. Unfortunately, optimal constructions for maximum-likelihood decoding do not perform well under iterative decoding. To overcome this limitation, we then introduce a new family of full-diversity LDPC codes that exhibit near-outage-limit performance under iterative decoding for all block-lengths. This family competes with multiplexed parallel turbo codes suitable for nonergodic channels and recently reported in the literature.Comment: Submitted to the IEEE Transactions on Information Theor

    Suboptimum receiver interfaces and space-time codes

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    Bit-interleaved coded modulation

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    Obesity reduces the pro-angiogenic potential of adipose tissue stem cell-derived extracellular vesicles (EVs) by impairing miR-126 content: impact on clinical applications

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    BACKGROUND/OBJECTIVES: Soluble factors and cell-derived extracellular vesicles (EVs) are crucial tissue repair mediators in cell-based therapy. In the present study, we investigate the therapeutic impact of EVs released by adipose tissue-derived stem cells (ASCs) recovered from obese subjects' visceral and subcutaneous tissues. METHODS: ASCs were recovered from 10 obese (oASCs) and 6 non-obese (nASCs) participants and characterized. In selected experiments, nASCs and oASCs were cultured with palmitic acid (PA) or high glucose (HG), respectively. EVs from obese (oEVs) and non-obese (nEVs) subjects' visceral and subcutaneous ASCs were collected after ultracentrifugation and analyzed for their cargo: microRNA-126 (miR-126), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 2 (MMP-2), and for their biological effects on endothelial cells (ECs). Western blotting analysis and loss- and gain-of function experiments were performed. RESULTS: oEVs show impaired angiogenic potential compared with nEVs. This effect depends on EV cargo: reduced content of VEGF, MMP-2 and, more importantly, miR-126. We demonstrate, using gain- and loss-of-function experiments, that this reduced miR-126 content leads to Spred1 upregulation and the inhibition of the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase pathway in ECs. We also show that PA treatment of nASCs translates into the release of EVs that recapitulate oEV cargo. Moreover, HG treatment of oASCs further reduces miR-126 EV content and EV-mediated in vitro angiogenesis. Finally, impaired pro-angiogenic potential is also detected in EVs released from obese subcutaneous adipose tissue-derived ASCs. CONCLUSIONS: These results indicate that obesity impacts on EV pro-angiogenic potential and may raise concerns about the use of adipose tissue-derived EVs in cell-based therapy in the obese setting

    Fundamentals of Multi-User MIMO Communications

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    In recent years, the remarkable promise of multiple-antenna techniques has motivated an intense research activity devoted to characterizing the theoretical and practical issues associated with multiple-input multiple-output wireless channels. This activity was first focused primarily on single-user communications but more recently there has been extensive work on multi-user settings. The aim of this chapter is to provide an overview of the fundamental information-theoretic results and practical implementation issues of multi-user multiple-antenna networks operating under various conditions of channel state information

    DISTINCTIVE PLASMA-ALDOSTERONE, 18-HYDROXYCORTICOSTERONE, and 18-HYDROXYDEOXYCORTICOSTERONE PROFILE in the 21-HYDROXYLASE, 17-ALPHA-HYDROXYLASE, and 11-BETA-HYDROXYLASE DEFICIENCY TYPES of CONGENITAL ADRENAL-HYPERPLASIA

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    SAN FRANCISCO GEN HOSP,MED CTR,CTR CLIN STUDY,SAN FRANCISCO,CA 94110UNIV CALIF SAN FRANCISCO,DEPT MED,SAN FRANCISCO,CA 94143ESCOLA PAULISTA MED,BR-04023 São Paulo,SP,BRAZILESCOLA PAULISTA MED,BR-04023 São Paulo,SP,BRAZILWeb of Scienc

    MINERALOCORTICOIDS in CONGENITAL ADRENAL-HYPERPLASIA

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    While hypertension is observed in only two of the three major subtypes of congenital adrenal hyperplasia (CAH), 11-beta- and 17-alpha-hydroxylase deficiencies, deoxycorticosterone (DOC) production is increased in all. the elevated zona fasciculata (ZF) DOC produces mineralocorticoid hypertension with suppressed renin and reduced potassium concentrations. the DOC levels in 21 -hydroxylase deficiency are in part produced by renin stimulation of the Zona glomerulosa (ZG) along with aldosterone. Assessment of the mineralocorticoid hormones of the ZF and ZF (17-deoxy steroids) provides additional unique characteristics of each subtype. Dissociation of DOC from cortisol is not unique to CAH. This dissociation is seen in other disorders and contrived conditions. There is a strong suggestion of a non-ACTH regulator of 17-deoxy steroids (DOC) that may contribute significantly to DOC production in general and effect DOC levels in CAH.UNIV CALIF SAN FRANCISCO,SAN FRANCISCO GEN HOSP,GEN CLIN RES CTR,SAN FRANCISCO,CA 94110ESCOLA PAULISTA MED SCH,BR-04023 São Paulo,BRAZILESCOLA PAULISTA MED SCH,BR-04023 São Paulo,BRAZILWeb of Scienc
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