180 research outputs found
Adaptive virtual MIMO single cluster optimization in a small cell
Adaptive Virtual MIMO optimized in a single cluster of small cells is shown in this paper to achieve near Shannon channel capacity when operating with partial or no Channel State Information. Although, access links have enormously increased in the recent years, the operational system complexity remains linear regardless of the number of access nodes in the system proposed. Adaptive Virtual MIMO optimized in a single cluster performs a theoretical information spectral efficiency, almost equal to that of the upper bounds of a typical mesh network, up to 43 bits/s/Hz at a SNR of 30dB while the BER performance remains impressively low hitting the 10−6 at an SNR of about 13 dB when the theoretical upper bound of an ideal small cell mesh network achieves the 10−6 at a SNR of 12.5 dB. In addition, in a sub-optimum channel condition, the channel capacity and BER performance of the proposed solution is shown to drastically delay saturation even for the very high SNR
Enhancing BER performance limit of BCH and RS codes using multipath diversity
Modern wireless communication systems suffer from phase shifting and, more importantly, from interference caused by multipath propagation. Multipath propagation results in an antenna receiving two or more copies of the signal sequence sent from the same source but that has been delivered via different paths. Multipath components are treated as redundant copies of the original data sequence and are used to improve the performance of forward error correction (FEC) codes without extra redundancy, in order to improve data transmission reliability and increase the bit rate over the wireless communication channel. For a proof of concept Bose, Ray-Chaudhuri, and Hocquenghem (BCH) and Reed-Solomon (RS) codes have been used as FEC to compare their bit error rate (BER) performances. The results showed that the wireless multipath components significantly improve the performance of FEC. Furthermore, FEC codes with low error correction capability and employing the multipath phenomenon are enhanced to perform better than FEC codes which have a bit higher error correction capability and did not utilise the multipath. Consequently, the bit rate is increased, and communication reliability is improved without extra redundancy
Targeted inhibition of aggrecanases prevents articular cartilage degradation and augments bone mass in the STR/Ort spontaneous model of osteoarthritis
BACKGROUND:Cartilage destruction in osteoarthritis (OA) is mediated mainly by MMPs and ADAMTSs. The therapeutic candidature of targeting aggrecanases has not yet been defined in joints where spontaneous OA arises due to genetic susceptibility, without a traumatic or load- induced aetiology such as the STR/Ort mouse. Nor do we know the long-term effect of aggrecanase inhibition on bone. METHODS:Using the STR/Ort spontaneously OA background, we have generated transgenic mice that overexpress [-1A]TIMP-3, either ubiquitously or conditionally in chondrocytes. [-1A]TIMP-3 is a variant of tissue inhibitor of metalloproteinase-3 (TIMP-3) that has an extra alanine at the N- terminus that selectively inhibits ADAMTSs, but not MMPs. We analysed a range of OA-related measures in all mice at 40 weeks of age. RESULTS:Mice expressing high [-1A]TIMP-3 levels were protected against the development of the OA whilst low expressers were not. Interestingly, we also found that high levels of [-1A]TIMP-3 transgene overexpression resulted in raised bone mass particularly in females. This regulation of bone mass is, at least, partly direct as primary adult osteoblasts infected with [-1A]TIMP-3 in vitro show elevated rates of mineralisation. CONCLUSIONS:The results provide evidence that [-1A]TIMP-3-mediated inhibition of aggrecanases can protect from cartilage degradation in naturally occurring OA mouse model and highlight a novel role that aggrecanases' inhibition may play in increased bone mass. This article is protected by copyright. All rights reserved
PAM-4 and duobinary direct modulation of a hybrid InP/SOI DFB laser for 40 Gb/s transmission over 2 km single mode fiber
We demonstrate 40 Gb/s PAM-4 and Duobinary direct modulation of a heterogeneously integrated InP on SOI DFB laser. Transmission measurement was performed using a 2 km NZ-DSF with a PRBS 2(15) and 1.5 V-pp swing voltage
Case report: Aqueous and Vitreous amino-acid concentrations in a patient with maple syrup urine disease operated on rhegmatogenous retinal detachment
Elimination of Endogenous Toxin, Creatinine from Blood Plasma Depends on Albumin Conformation: Site Specific Uremic Toxicity & Impaired Drug Binding
Uremic syndrome results from malfunctioning of various organ systems due to the retention of uremic toxins which, under normal conditions, would be excreted into the urine and/or metabolized by the kidneys. The aim of this study was to elucidate the mechanisms underlying the renal elimination of uremic toxin creatinine that accumulate in chronic renal failure. Quantitative investigation of the plausible correlations was performed by spectroscopy, calorimetry, molecular docking and accessibility of surface area. Alkalinization of normal plasma from pH 7.0 to 9.0 modifies the distribution of toxin in the body and therefore may affect both the accumulation and the rate of toxin elimination. The ligand loading of HSA with uremic toxin predicts several key side chain interactions of site I that presumably have the potential to impact the specificity and impaired drug binding. These findings provide useful information for elucidating the complicated mechanism of toxin disposition in renal disease state
Anti- Japanese-Encephalitis-Viral Effects of Kaempferol and Daidzin and Their RNA-Binding Characteristics
Background: New therapeutic tools and molecular targets are needed for treatment of Japanese encephalitis virus (JEV) infections. JEV requires an a-1 translational frameshift to synthesize the NS1 ’ protein required for viral neuroinvasiveness. Several flavonoids have been shown to possess antiviral activity in vitro against a wide spectrum of viruses. To date, the antiviral activities of flavonol kaempferol (Kae) and isoflavonoid daidzin (Dai) against JEV have not been described. Methodology/Principal Findings: The 50 % cytotoxic concentration (CC50) and 50 % effective concentration (EC50) against JEV were investigated in BHK21 cells by MTS reduction. Activity against viral genomic RNA and proteins was measured by real-time RT-PCR and western blotting. The frameshift site RNA-binding characterization was also determined by electrospray ionization mass spectrometry, isothermal titration calorimetry and autodocking analysis. EC 50 values of Kae and Dai were 12.6 and 25.9 mM against JEV in cells pretreated before infection, whereas in cells infected before treatment, EC50 was 21.5 and 40.4 mM, respectively. Kae exhibited more potent activity against JEV and RNA binding in cells following internalization through direct inhibition of viral replication and protein expression, indicating that its antiviral activity was principally due to direct virucidal effects. The JEV frameshift site RNA (fsRNA) was selected as a target for assaying Kae and Dai. ITC of fsRNA revealed an apparent Kb value for Kae that was nine fold stronger than that for Dai. This binding was confirmed and localized to the RNA using ESI-MS and autodock analysis. Kae could form non-covalent complexes wit
Induction of apoptosis of human primary osteoclasts treated with extracts from the medicinal plant Emblica officinalis
<p>Abstract</p> <p>Background</p> <p>Osteoclasts (OCs) are involved in rheumatoid arthritis and in several pathologies associated with bone loss. Recent results support the concept that some medicinal plants and derived natural products are of great interest for developing therapeutic strategies against bone disorders, including rheumatoid arthritis and osteoporosis. In this study we determined whether extracts of <it>Emblica officinalis </it>fruits display activity of possible interest for the treatment of rheumatoid arthritis and osteoporosis by activating programmed cell death of human primary osteoclasts.</p> <p>Methods</p> <p>The effects of extracts from <it>Emblica officinalis </it>on differentiation and survival of human primary OCs cultures obtained from peripheral blood were determined by tartrate-acid resistant acid phosphatase (TRAP)-positivity and colorimetric MTT assay. The effects of <it>Emblica officinalis </it>extracts on induction of OCs apoptosis were studied using TUNEL and immunocytochemical analysis of FAS receptor expression. Finally, <it>in vitro </it>effects of <it>Emblica officinalis </it>extracts on NF-kB transcription factor activity were determined by gel shift experiments.</p> <p>Results</p> <p>Extracts of <it>Emblica officinalis </it>were able to induce programmed cell death of mature OCs, without altering, at the concentrations employed in our study, the process of osteoclastogenesis. <it>Emblica officinalis </it>increased the expression levels of Fas, a critical member of the apoptotic pathway. Gel shift experiments demonstrated that <it>Emblica officinalis </it>extracts act by interfering with NF-kB activity, a transcription factor involved in osteoclast biology. The data obtained demonstrate that <it>Emblica officinalis </it>extracts selectively compete with the binding of transcription factor NF-kB to its specific target DNA sequences. This effect might explain the observed effects of <it>Emblica officinalis </it>on the expression levels of interleukin-6, a NF-kB specific target gene.</p> <p>Conclusion</p> <p>Induction of apoptosis of osteoclasts could be an important strategy both in interfering with rheumatoid arthritis complications of the bone skeleton leading to joint destruction, and preventing and reducing osteoporosis. Accordingly, we suggest the application of <it>Emblica officinalis </it>extracts as an alternative tool for therapy applied to bone diseases.</p
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