Environmental investigation of a legionellosis outbreak in western Sydney: the role of molecular profiling

Colitis following colonoscopy is an acute, self-limited condition characterized by tenesmus and bloody diarrhea appearing within 48 hours of colonoscopy or sigmoidoscopy. Glutaraldehyde used for disinfection of the endoscopes is considered to be the main etiological agent. Three cases of severe acute self-limited colitis are described in this report. All three were observed within one week, and showed the typical anamnestic, clinical, endoscopic, histological, and radiological features of glutaraldehyde-induced colitis. The main characteristics in these cases were the time relationship with colonoscopy and the severity of the clinical presentation, with symptoms of systemic reaction and intense and diffuse edema of the colonic mucosa. The clinical and morphological features may mimic those of colonic ischemia. All three patients recovered completely within a few days, one spontaneously and two after treatment with steroids, antibiotics, and mesalazine. Acute colitis following colonoscopy should be regarded as one of the complications related to colonoscopy, and it should be taken into account in the differential diagnosis of acute colitis.     

Beam steering of nonlinear oscillator arrays through manipulation of coupling phases

This paper describes three phase-shifterless beam steering techniques which exploit the synchronization properties of coupled nonlinear oscillator arrays. In each, the control parameters are the coupling phases of the local interactions between elements. The one-dimensional oscillator arrays under consideration are described by Phase Model-type equations, implying the assumption that the amplitude dynamics have achieved a steady state. Linear stability analyzes for each technique are provided which reveal significant differences in attainable scan angles.     

Project Numina: enhancing student learning with handheld computers

Despite recent technological advances, the promise of the virtual classroom with anywhere, anytime access and rich data sharing remains largely unfulfilled. To address this need, Project Numina researchers are developing a mobile learning environment that fosters collaboration among students and between students and instructors.     

Automated Purification of DNA from Large Samples: A Study of Effectiveness and Labor Efficiency

Investigations into the underlying genetic contributions to human disease are transitioning from small family-based traditional linkage analyses to large population-based studies designed to identify genetic factors in more complex and common diseases that have the greatest impact on human health. These types of studies have driven the need for larger numbers of samples for analysis and more efficient and effective methods for DNA purification, especially for large samples that provide sufficient quantities of DNA for extensive analysis. The AUTOPURE LS™ Nucleic Acid Purification Instrument, by Gentra Systems, Inc., a platform capable of high-throughput sample purification from large samples, was developed to meet the demands of these large studies. This article presents data demonstrating the equivalency of DNA purified using the AUTOPURE LS automated instrument and the manual method based on the same purification process. In addition, we present data demonstrating the in-lab time savings realized by automating the purification process.     

Vasopressin modulation of peritoneal, lymphatic, and plasma drug exposure following intraperitoneal administration

i.p. administration of cytotoxic drugs for the treatment of regionally confined cancers results in a greater total drug exposure [area under the concentration x time curve (AUC)] for the peritoneal fluid and regional lymphatics than for plasma. We sought to augment the relative advantage of i.p. administration further through modulation of peritoneal clearance by reduction in splanchnic blood flow. Pigs were treated with 5-fluorouracil, etoposide (VP-16), and carboplatin (CBDCA) alone by the i.p. route or with the same drugs in combination with i.v. lypressin, a synthetic vasopressin analogue, which reduces splanchnic blood flow. Drug concentrations in peritoneal fluid, plasma, and thoracic duct lymph were monitored over the ensuing 6 h. The pharmacokinetics of 5-fluorouracil were not altered by vasopressin; however, vasopressin increased the peritoneal fluid:plasma AUC ratio for CBDCA from 30.6 +/- 5.6 to 70. 6 +/- 7.4 (P < 0.01) and increased the lymph:plasma AUC ratio from 1.1 +/- 0.4 to 2.6 +/- 0.22 (P < 0.05). In the case of VP-16, vasopressin increased the peritoneal fluid:plasma AUC ratio from 129 +/- 35 to 350 +/- 76 (P < 0.05) and the lymph:plasma AUC ratio from 2.1 +/- 0.6 to 10.6 +/- 3.5 (P < 0.05). Concurrent i.v. administration of vasopressin can increase the pharmacokinetic advantage of the i.p. route of administration of CBDCA and VP-16 markedly in the pig model. These data suggest that the strategy of concurrent i.p. administration of CBDCA or VP-16 plus an agent that reduces splanchnic blood flow may increase the dose intensity in the abdominal cavity and intraabdominal lymphatic tissue substantially without increasing systemic toxicity.     

Multilayered Lipid Membrane Stacks for Biocatalysis Using Membrane Enzymes

Multilayered or stacked lipid membranes are a common principle in biology and have various functional advantages compared to single‐lipid membranes, such as their ability to spatially organize processes, compartmentalize molecules, and greatly increase surface area and hence membrane protein concentration. Here, a supramolecular assembly of a multilayered lipid membrane system is reported in which poly‐l ‐lysine electrostatically links negatively charged lipid membranes. When suitable membrane enzymes are incorporated, either an ubiquinol oxidase (cytochrome bo ₃ from Escherichia coli) or an oxygen tolerant hydrogenase (the membrane‐bound hydrogenase from Ralstonia eutropha), cyclic voltammetry (CV) reveals a linear increase in biocatalytic activity with each additional membrane layer. Electron transfer between the enzymes and the electrode is mediated by the quinone pool that is present in the lipid phase. Using atomic force microscopy, CV, and fluorescence microscopy it is deduced that quinones are able to diffuse between the stacked lipid membrane layers via defect sites where the lipid membranes are interconnected. This assembly is akin to that of interconnected thylakoid membranes or the folded lamella of mitochondria and has significant potential for mimicry in biotechnology applications such as energy production or biosensing.     

Superlattice nanowire pattern transfer (SNAP)

During the past 15 years or so, nanowires (NWs) have emerged as a new and distinct class of materials. Their novel structural and physical properties separate them from wires that can be prepared using the standard methods for manufacturing electronics. NW-based applications that range from traditional electronic devices (logic and memory) to novel biomolecular and chemical sensors, thermoelectric materials, and optoelectronic devices, all have appeared during the past few years. From a fundamental perspective, NWs provide a route toward the investigation of new physics in confined dimensions. Perhaps the most familiar fabrication method is the vapor-liquid-solid (VLS) growth technique, which produces semiconductor nanowires as bulk materials. However, other fabrication methods exist and have their own advantages. In this Account, I review a particular class of NWs produced by an alternative method called superlattice nanowire pattern transfer (SNAP). The SNAP method is distinct from other nanowire preparation methods in several ways. It can produce large NW arrays from virtually any thin-film material, including metals, insulators, and semiconductors. The dimensions of the NWs can be controlled with near-atomic precision, and NW widths and spacings can be as small as a few nanometers. In addition, SNAP is almost fully compatible with more traditional methods for manufacturing electronics. The motivation behind the development of SNAP was to have a general nanofabrication method for preparing electronics-grade circuitry, but one that would operate at macromolecular dimensions and with access to a broad materials set. Thus, electronics applications, including novel demultiplexing architectures; large-scale, ultrahigh-density memory circuits; and complementary symmetry nanowire logic circuits, have served as drivers for developing various aspects of the SNAP method. Some of that work is reviewed here. As the SNAP method has evolved into a robust nanofabrication method, it has become an enabling tool for the investigation of new physics. In particular, the application of SNAP toward understanding heat transport in low-dimensional systems is discussed. This work has led to the surprising discovery that Si NWs can serve as highly efficient thermoelectric materials. Finally, we turn toward the application of SNAP to the investigation of quasi-one-dimensional (quasi-1D) superconducting physics in extremely high aspect ratio Nb NWs.     

Controlled fabrication and electrical properties of long quasi-one-dimensional superconducting nanowire arrays

We report a general method for reliably fabricating quasi-one-dimensional superconducting nanowire arrays, with good control over nanowire cross section and length, and with full compatibility with device processing methods. We investigate Nb nanowires with individual nanowire cross sectional areas that range from bulklike to 10 x 11 nm, and with lengths from 1 to 100 microm. Nanowire size effects are systematically studied. In particular, a comprehensive investigation of influence of nanowire length on superconductivity is reported for the first time. All results are interpreted within the context of phase-slip models.