2,775 research outputs found

    Nature-Inspired Interconnects for Self-Assembled Large-Scale Network-on-Chip Designs

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    Future nano-scale electronics built up from an Avogadro number of components needs efficient, highly scalable, and robust means of communication in order to be competitive with traditional silicon approaches. In recent years, the Networks-on-Chip (NoC) paradigm emerged as a promising solution to interconnect challenges in silicon-based electronics. Current NoC architectures are either highly regular or fully customized, both of which represent implausible assumptions for emerging bottom-up self-assembled molecular electronics that are generally assumed to have a high degree of irregularity and imperfection. Here, we pragmatically and experimentally investigate important design trade-offs and properties of an irregular, abstract, yet physically plausible 3D small-world interconnect fabric that is inspired by modern network-on-chip paradigms. We vary the framework's key parameters, such as the connectivity, the number of switch nodes, the distribution of long- versus short-range connections, and measure the network's relevant communication characteristics. We further explore the robustness against link failures and the ability and efficiency to solve a simple toy problem, the synchronization task. The results confirm that (1) computation in irregular assemblies is a promising and disruptive computing paradigm for self-assembled nano-scale electronics and (2) that 3D small-world interconnect fabrics with a power-law decaying distribution of shortcut lengths are physically plausible and have major advantages over local 2D and 3D regular topologies

    Home Parenteral Nutrition in Patients with Advanced Cancer: A Systematic Review and Meta-Analysis

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    The use of home parenteral nutrition (HPN) in patients with incurable cancer remains controversial with significant variation worldwide. We aimed to systematically evaluate the literature from 1960 to 2018 examining the use of HPN in advanced cancer patients for all intestinal failure indications and assess the potential benefits/burdens of HPN in this cohort of patients. The primary end point was survival and secondary end points were quality of life and nutritional/performance status. Meta-analysis was performed with a random effects model, where suitable. Of 493 studies retrieved, 22 met the quality inclusion criteria. Studies were mainly conducted in Western countries (Italy, USA, Canada, Germany), including a total of 3564 patients (mean age 57.8 years). Mean duration for HPN was 5.0 mo. Mean overall survival was 7.3 mo. Patients with improved performance status survived for longer on HPN. Quality of life was sparsely reported though there was no observed negative impact of PN. HPN-related complications were reported in eight studies only and were mainly catheter-related blood stream infections. In conclusion, HPN is used for several indications in advanced cancer, though there is significant heterogeneity of results. Disparities in geographical distribution of the studies may reflect variation in accessing HPN

    p53-Mediated downregulation of H ferritin promoter transcriptional efficiency via NF-Y

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    The tumor suppressor protein p53 triggers many of the cellular responses to DNA damage by regulating the transcription of a series of downstream target genes. p53 acts on the promoter of the target genes by interacting with the trimeric transcription factor NF-Y. H ferritin promoter activity is tightly dependent on a multiprotein complex called Bbf; on this complex NF-Y plays a major role. The aim of this work was to study the modulation of H ferritin expression levels by p53. CAT reporter assays indicate that: (i) p53 overexpression strongly downregulates the transcriptional efficiency driven by an H ferritin promoter construct containing only the NF-Y recognition sequence and that the phenomenon is reverted by p53 siRNA; (ii) the p53 C-terminal region is sufficient to elicitate this regulation and that a correct C-terminal acetylation is also required. The H ferritin promoter displays no p53-binding sites; chromatin immunoprecipitation assays indicate that p53 is recruited on this promoter by NF-Y. The p53–NF-Y interaction does not alter the NF-Y DNA-binding ability as indicated by electrophoretic mobility shift assay (EMSA) analysis. These results demonstrate that the gene coding for the H ferritin protein belongs to the family of p53-regulated genes, therefore adding a new level of complexity to the regulation of the H ferritin transcription and delineate a role for this protein in a series of cellular events triggered by p53 activation

    Hypophosphataemia after intravenous iron therapy with ferric carboxymaltose—Real world experience from a tertiary centre in the UK

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    Background: Iron deficiency is the most common global cause of anaemia. Intravenous (IV) iron is used to correct iron deficiency anaemia (IDA) where oral iron cannot be used. Despite being effective, certain IV iron formulations cause significant hypophosphataemia. However, current knowledge on the clinical consequences of IV iron‐induced hypophosphataemia is broadly anecdotal or limited to isolated case reports. / Aims: To retrospectively examine the incidence and potential clinical consequences of hypophosphataemia post‐IV ferric carboxymaltose (FCM) in hospitalised patients with IDA (mixed aetiology). / Methods: Data were collected for 162 patients, who received a total of 169 FCM courses during a 2‐year audit period. Outcomes included incidence of moderate/severe hypophosphataemia (serum phosphate <0.65 mmol/L) ≀90 days post‐FCM, changes in alkaline phosphatase, need for phosphate replacement, and length of hospital stay. / Results: The incidence of moderate/severe hypophosphataemia post‐FCM was 33.7%; within this group the rate of severe hypophosphataemia (serum phosphate ≀0.32 mmol/L) was 8.8%. Moderate/severe hypophosphataemia persisted, with 35% of patients having a serum phosphate of <0.65 mmol/L for ≀90 days at the last measurement after IV FCM. Intervention with IV phosphate—an average of 4.4 infusions per person—was required in 29.8% of cases with moderate/severe hypophosphataemia. FCM‐induced moderate/severe hypophosphataemia was associated with a significantly longer hospital stay (P < 0.0035). / Conclusions: Moderate/severe hypophosphataemia is a frequent adverse drug reaction with FCM. In our study, FCM‐induced moderate/severe hypophosphataemia was also persistent, often required treatment, and was associated with longer hospital stay

    Refeeding syndrome in adults receiving total parenteral nutrition: An audit of practice at a tertiary UK centre

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    Background & aims: The key to preventing refeeding syndrome (RS) is identifying and appropriately managing patients at risk. We evaluated our clinical management of RS risk in patients starting total parenteral nutrition (TPN). / Methods: Patients commencing TPN at University College London Hospital between January and July 2015 were prospectively followed-up for 7-days. Eighty patients were risk assessed for RS and categorized into risk groups. High and low risk RS groups were compared focussing on the onset of biochemical features of RS (hypophosphatemia, hypokalaemia and hypomagnesemia) and initial clinical assessment. Statistical analysis was conducted using t-tests and Mann–Whitney U tests. / Results: Sixty patients (75%) were identified as high-risk for RS and received lower initial calories (12.8 kcal/kg/day, p < 0.05). All high-risk patients received a high potency vitamin preparation compared to 35% in the low risk group (p < 0.05). Daily phosphate, magnesium and potassium plasma levels were monitored for seven days in 25%, 30% and 53.8% of patients, respectively. Hypophosphatemia developed in 30% and hypomagnesaemia and hypokalaemia in 27.5% of all patients. Approximately 84% of patients had one or more electrolyte abnormalities, which occurred more frequently in high-risk RS patients (p < 0.05). Low risk patients developed mild hypophosphatemia at a much lower percentage than high-risk RS (20% vs 33.3%, respectively). / Conclusion: A significant proportion of patients commencing TPN developed biochemical features of RS (but no more serious complications) despite nutritional assessment, treatment, and follow up in accordance with national recommendations. High vs low risk RS patients were more likely to have electrolyte abnormalities after receiving TPN regardless of preventative measures. Additional research is required to further optimise the initial nutritional approach to prevent RS in high-risk patients

    Multicentre randomised controlled trial comparing standard and high resolution optical technologies in colorectal cancer screening.

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    Background and objectives: The UK bowel cancer screening programme (BCSP) has been established for the early detection of colorectal cancer offering colonoscopy to patients screened positive by faecal occult blood tests. In this multisite, prospective, randomised controlled trial, we aimed to compare the performance of Standard Definition Olympus Lucera (SD-OL) with Scope Guide and the High Definition Pentax HiLine (HD-PHL). Patients and methods: Subjects undergoing a colonoscopy as part of the UK National BCSP at four UK sites were randomised to an endoscopy list run using either SD-OL or HD-PHL. Primary endpoints were polyp and adenoma detection rate (PDR and ADR, respectively) as well as polyp size, morphology and histology characteristics. Results: 262 subjects (168 males, mean age 66.3±4.3 years) were colonoscoped (133 patients with HD-PHL while 129 with SD-OL). PDR and ADR were comparable within the two optical systems. The HD-PHL group resulted in a PDR 55.6% and ADR 43.6%; the SD-OL group had PDR 56.6% and ADR 45.7%. HD-PHL was significantly superior to SD-OL in detection of flat adenomas (18.6% vs 5.2%, p<0.001), but not detection of pedunculated or sessile polyps. Patient comfort, use of sedation and endoscopist perception of procedural difficulty resulted similar despite the use of Scope Guide with SD-OL. Conclusion: PDR and ADR were not significantly different between devices. The high-resolution colonoscopy system HD-PHL may improve polyp detection as compared with standard resolution technology in detecting flat adenomas. This advantage may have clinically significant implications for missed lesion rates and post-colonoscopy interval colorectal cancer rates
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