Enhanced Performance of a Molecular Photoacoustic Imaging Agent by Encapsulation in Mesoporous Silicon Nanoparticles

Photoacoustic (PA) imaging allows visualization of the physiology and pathology of tissues with good spatial resolution and relatively deep tissue penetration. The method converts near‐infrared (NIR) laser excitation into thermal expansion, generating pressure transients that are detected with an acoustic transducer. Here, we find that the response of the PA contrast agent indocyanine green (ICG) can be enhanced 17‐fold when it is sealed within a rigid nanoparticle. ICG encapsulated in particles composed of porous silicon (pSiNP), porous silica, or calcium silicate all show greater PA contrast relative to equivalent quantities of free ICG, with the pSiNPs showing the strongest enhancement. A liposomal formulation of ICG performs similar to free ICG, suggesting that a rigid host nanostructure is necessary to enhance ICG performance. The improved response of the nanoparticle formulations is attributed to the low thermal conductivity of the porous inorganic hosts and their ability to protect the ICG payload from photolytic and/or thermal degradation. The translational potential of ICG‐loaded pSiNPs as photoacoustic probes is demonstrated via imaging of a whole mouse brain.     

Highly selective ratiometric fluorescence determination of Eu3+ ion based on (4E)-4-(2-phenyldiazenyl)-2-((E)-(2-aminoethylimino)methyl)phenol

(4E)-4-(2-phenyldiazenyl)-2-((E)-(2-aminoethylimino)methyl)phenol (PAMP) was synthesized for the first time and used as a ratiometric fluorescent chemosensor for recognition of Eu³⁺ ions in acetonitrile solution. PAMP shows a fluorescent emission at 536 nm. When it forms a complex with Eu³⁺ ion, two new fluorescent enhancements at 418 and 496 nm appeared. In acetonitrile solution, the blue shift of fluorescent emission upon europium binding is due to the formation of a 1:1 metal ligand complex. The chemosensor shows a linear response toward Eu³⁺ in the range of 8.3 × 10^? 8 M to 8.3 × 10^? 6 M. The new fluorescent probe exhibits high selectivity toward Eu³⁺ ions over a large number of interfering cations.     

Associations between serotonin transporter gene promoter region (5-HTTLPR) polymorphism and gaze bias for emotional information.

The serotonin transporter promoter region polymorphism (5-HTTLPR) is associated with neural response to negative images in brain regions involved in the experience of emotion. However, the behavioral implications of this sensitivity have been studied far less extensively. The current study used eye-tracking methodology to examine how individuals genotyped for the 5-HTTLPR, including the single nucleotide polymorphism (SNP) rs25531, allocated attention during prolonged (30-s) exposure to face stimuli depicting positive and negative emotion. Short 5-HTTLPR allele carriers and carriers of the long allele with guanine at the sixth nucleotide (S/LG) displayed a stronger gaze bias (total fixation time, number of fixations, mean fixation length) for positive than for sad, threat, or neutral stimuli. In contrast, those homozygous for the long 5-HTTLPR allele with adenine at the sixth nucleotide (LA) viewed the emotion stimuli in an unbiased fashion. Time course analyses indicated no initial 5-HTTLPR group differences; however, S/LG 5-HTTLPR allele carriers were more likely than LA 5-HTTLPR homozygotes to direct gaze toward happy than toward sad stimuli over time. This bias toward positive stimuli during the later stages of information processing likely reflects a strategic effort to downregulate heightened reactivity to negative stimuli among 5-HTTLPR S/LG allele carriers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A High Performance Message-Passing System for Network of Workstations

With the proliferation of Network of Workstations (NOW) environment, there has been a great demand for a high performance message-passing system to implement High Performance Distributed Computing (HPDC) applications over NOW environment. NYNET (ATM wide area network testbed in New York state) Communication System (NCS) is a multithreaded message-passing system developed at Syracuse University that provides low-latency and high-throughput communication services over the Asynchronous Transfer Mode (ATM) based HPDC environment. NCS provides High Performmance Application Communication Interface (HPI) to support applications that demand high-throughput and low-latency communication services.This paper outlines the general architecture of NCS and presents the implementation approach of NCS HPI over an ATM network. This interface has been developed by modifying Fore Systems' ATM Application Programming Interface (API) and its device driver. NCS HPI uses read/writetrap routines to bypass traditional operating system calls and kernel-level communication interface (e.g. UNIX System V Streams). It reduces latency, data transfer time, and avoid using traditional communication protocols (e.g., TCP/IP). This substantially improves the communication performance.     

Evolutionary coincidence-based ontology mapping extraction

Abstract: Ontology matching is a process for selection of a good alignment across entities of two (or more) ontologies. This can be viewed as a two-phase process of (1) applying a similarity measure to find the correspondence of each pair of entities from two ontologies, and (2) extraction of an optimal or near optimal mapping. This paper is focused on the second phase and introduces our evolutionary approach for that. To be able to do so, we need a mechanism to score different possible mappings. Our solution is a weighting mechanism named coincidence-based weighting . A genetic algorithm is then introduced to create better mappings in successive iterations. We will explain how we code a mapping as well as our crossover and mutation functions. Evaluation of the algorithm is shown and discussed.     

Tester Memory Requirements and Test Application Time Reduction for Delay Faults with Digital Captureless Test Sensors

In this paper, we present a technique called Digital Captureless Delay Testing Sensors (DCDTS). This technique allows the detection of delay faults left uncovered by launch-on-capture transitions due to excessive resources (mainly test time or tester memory) requirements, with top-off random launch-on-shift patterns that do not require fast switching scan enable signals. The DCDTS random patterns are internally generated, requiring virtually no additional test application time or tester memory. As such, DCDTS can be seen as a new way to save both test time and tester memory. Results show that DCDTS can achieve pattern volume and test time reduction factors of up to 3. When used in complement to existing compression techniques, DCDTS has the potential to triple their pattern volume (test application time) compression (reduction) rate. Area/performance overhead and technical obstacles to automation are minimal. An automated sensor selection procedure is proposed, with reasonable CPU time.     

Task-based imaging of colon cancer in the Apc(Min/+) mouse model

Optical coherence tomography (OCT), laser-induced fluorescence (LIF), and laser-scanning confocal microscopy (LSCM) were used for the task of multimodal study of healthy and adenomatous mouse colon. The results from each modality were compared with histology, which served as the gold standard. The Apc(Min/+) genetic mouse model of colon cancer was compared with wild-type mice. In addition, a special diet was used for the task of studying the origins of a 680 nm autofluorescent signal that was previously observed in colon. The study found close agreement among each of the modalities and with histology. All four modalities were capable of identifying diseased tissue accurately. The OCT and LSCM images provided complementary structural information about the tissue, while the autofluorescence signal measured by LIF and LSCM provided biochemical information. OCT and LIF were performed in vivo and nondestructively, while the LSCM and histology required extraction of the tissue. The magnitude of the 680 nm signal correlates with chlorophyll content in the mouse diet, suggesting that the autofluorescent compound is a dietary metabolite.     

A fuzzy logic based power system stabilizer with learning ability

A fuzzy logic-based power system stabilizer (PSS) with learning ability is proposed in this paper. The proposed PSS employs a multilayer adaptive network. The network is trained directly from the input and the output of the generating unit. The algorithm combines the advantages of artificial neural networks (ANNs) and fuzzy logic control (FLC) schemes. Studies show that the proposed adaptive network-based fuzzy logic PSS (ANF PSS) can provide good damping of power systems over a wide range of operating conditions and improve the dynamic performance of the power system