Selective patterning of gold surfaces by core/shell, semisoft hybrid nanoparticles

The generation of patterned surfaces with well-defined nano- and microdomains is demonstrated by attaching core/shell, semisoft nanoparticles with narrow size distribution to microdomains of a gold-coated silicon wafer. Near monodisperse nanoparticles are prepared using reversible addition-fragmentation chain transfer (RAFT) polymerization, initiated from a silica surface, to prepare a polystyrene shell around a silica core. The particles are then used as-prepared, or after aminolysis of the terminal thiocarbonyl group of the polystyrene shell, to give thiol-terminated nanoparticles. When gold-coated silicon wafers are immersed into very dilute suspensions of these particles (as low as 0.004 wt%), both types of particles are shown to adhere to the gold domains. The thiolated particles adhere selectively to the gold microdomains, allowing for microdomain patterning, while particles that contain the trithiocarbonate functionality lead to a much more even coverage of the gold surface with fewer particle aggregations

Invasive mould infections: a multi-disciplinary update

Systemic fungal infections remain a significant cause of mortality in neutropenic and immunocompromised patients, despite advances in their diagnosis and treatment. The incidence of such infections is rising due to the use of intensive chemotherapy regimens in patients with solid tumours or haematological cancers, the increasing numbers of allogeneic haematopoietic stem cell and solid organ transplants, and the use of potent immunosuppressive therapy in patients with autoimmune disorders. In addition, the epidemiology of systemic fungal infections is changing, with atypical species such as Aspergillus terreus and zygomycetes becoming more common. Treatment has traditionally focused on empirical therapy, but targeted pre-emptive therapy in high-risk patients and prophylactic antifungal treatment are increasingly being adopted. New treatments, including lipid formulations of amphotericin B, second-generation broad-spectrum azoles, and echinocandins, offer effective antifungal activity with improved tolerability compared with older agents; the potential impact of these treatments is reflected in their inclusion in current treatment and prophylaxis guidelines. New treatment strategies, such as aerosolized lipid formulations of amphotericin B, may also reduce the burden of mortality associated with systemic fungal infections. The challenge is to identify ways of coupling potentially effective treatments with early and reliable identification of patients at highest risk of infectio

Auto-Pipe: A Pipeline Design and Evaluation System

Auto-Pipe is a tool that aids in the design, evaluation, and implementation of pipelined applications that are distributed across a set of heterogeneous devices including multiple processors and FPGAs. It has been developed to meet the needs arising in the domains of communications, computation on large datasets, and real time streaming data applications. In this paper, the Auto-Pipe design flow is introduced and two sample applications, developed for compatibility with the Auto-Pipe system, are presented. The sample applications are the Triple-DES encryption standard and a subset of the signal-processing pipeline for VERITAS, a high-energy gamma-ray astrophysics experiment. These applications are analyzed and one phase of the Auto-Pipe design flow is illustrated. The results demonstrate the performance implications of different task-to-stage and stage-to-platform (e.g., processor, FPGA) assignments

Invasive fungal infections in neutropenic enterocolitis: A systematic analysis of pathogens, incidence, treatment and mortality in adult patients

BACKGROUND: Neutropenic enterocolitis is a life-threatening complication most frequently occurring after intensive chemotherapy in acute leukaemias. Gramnegative bacteria constitute the most important group of causative pathogens. Fungi have also been reported, but their practical relevance remains unclear. The guidelines do not address concrete treatment recommendations for fungal neutropenic enterocolitis. METHODS: Here, we conducted a metaanalysis to answer the questions: What are frequency and mortality of fungal neutropenic enterocolitis? Do frequencies and microbiological distribution of causative fungi support empirical antimycotic therapy? Do reported results of antimycotic therapy in documented fungal neutropenic enterocolitis help with the selection of appropriate drugs? Following a systematic search, we extracted and summarised all detail data from the complete literature. RESULTS: Among 186 articles describing patients with neutropenic enterocolitis, we found 29 reports describing 53 patients with causative fungal pathogens. We found no randomised controlled trial, no good quality cohort study and no good quality case control study on the role of antifungal treatment. The pooled frequency of fungal neutropenic enterocolitis was 6.2% calculated from all 860 reported patients and 3.4% calculated from selected representative studies only. In 94% of the patients, Candida spp. were involved. The pooled mortality rate was 81.8%. Most authors did not report or perform antifungal therapy. CONCLUSION: In patients with neutropenic enterocolitis, fungal pathogens play a relevant, but secondary role compared to bacteria. Evidence concerning therapy is very poor, but epidemiological data from this study may provide helpful clues to select empiric antifungal therapy in neutropenic enterocolitis

Exploiting locality to ameliorate packet queue contention and serialization

Packet processing systems maintain high throughput despite relatively high memory latencies by exploiting the coarse-grained parallelism available between packets. In particular, multiple processors are used to overlap the processing of multiple packets. Packet queuing—the fundamental mechanism enabling packet scheduling, differentiated services, and traffic isolation—requires a read-modify-write operation on a linked list data structure to enqueue and dequeue packets; this operation represents a potential serializing bottleneck. If all packets awaiting service are destined for different queues, these read-modify-write cycles can proceed in parallel. However, if all or many of the incoming packets are destined for the same queue, or for a small number of queues, then system throughput will be serialized by these sequential external memory operations. For this reason, low latency SRAMs are used to implement the queue data structures. This reduces the absolute cost of serialization but does not eliminate it; SRAM latencies determine system throughput. In this paper we observe that the worst-case scenario for packet queuing coincides with the best-case scenario for caches: i.e., when locality exists and the majority of packets are destined for a small number of queues. The main contribution of this work is the queuing cache, which consists of a hardware cache and a closely coupled queuing engine that implements queue operations. The queuing cache improves performance dramatically by moving the bottleneck from external memory onto the packet processor, where clock rates are higher and latencies are lower. We compare the queuing cache to a number of alternatives, specifically, SRAM controllers with: no queuing support, a softwarecontrolled cache plus a queuing engine (like that used on Intel’s IXP network processor), and a hardware cache. Relative to these models, we show that a queuing cache improves worst-case throughput by factors of 3.1, 1.5, and 2.1 and the throughput of real-world traffic traces by factors of 2.6, 1.3, and 1.75, respectively. We also show that the queuing cache decreases external memory bandwidth usage, on-chip communication, and the num

Liquid Architecture

We present an implementation of a liquid-architecture system that supports efficient development, prototyping, and performance evaluation of custom architectures. The implementation integrates the LEON soft-core, SPARCcompatible processor into the Field-programmable Port Extender (FPX). The resulting platform can be instantiated, configured, and executed via the Internet

Auto-pipe and the X language: A pipeline design tool and description language

Auto-Pipe is a tool that aids in the design, evaluation and implementation of applications that can be executed on computational pipelines (and other topologies) using a set of heterogeneous devices including multiple processors and FPGAs. It has been developed to meet the needs arising in the domains of communications, computation on large datasets, and real time streaming data applications. This paper introduces the Auto-Pipe design flow and the X design language, and presents sample applications. The applications include the Triple-DES encryption standard, a subset of the signal-processing pipeline for VER-ITAS, a high-energy gamma-ray astrophysics experiment. These applications are discussed and their description in X is presented. From X, simulations of alternative system designs and stage-to-device assignments are obtained and analyzed. The complete system will permit production of executable code and bit maps that may be downloaded onto real devices. Future work required to complete the Auto-Pipe design tool is discussed. 1