Enhancing spectral shifts of plasmon-coupled noble metal nanoparticles for sensing applications

Noble metal nanoparticles possess very large scattering cross-sections, which make them useful as tags in biosensing assays with the potential to detect even single binding events. In this study, we investigated the effects of nanoparticle size on the shift in the light scattering spectrum following formation of Au–Au, Ag–Ag or Ag–Au dimers using FDTD simulations. We discuss the use of a color camera to detect these spectral changes for application in a target-induced dimerization sensing assay. Dimerization of Au nanoparticles induced a larger shift in color compared to Ag nanoparticles. Heterodimers composed of 60 nm Ag and 40 nm Au demonstrated an even larger spectral shift and color response compared to the best homodimer pair (80–40 nm Au). The increased spectral shift of the Ag–Au heterodimer was subsequently observed experimentally for the DNA-induced dimerization of nanoparticles, showing that careful selection of nanoparticle size and composition can significantly enhance recognition of nanoparticle dimerization events for use in (color) sensing assays

Toward efficient modification of large gold nanoparticles with DNA

DNA-coated gold nanoparticles are one of the most researched nano-bio hybrid systems. Traditionally their synthesis has been a long and tedious process, involving slow salt addition and long incubation steps. This stems from the fact that both DNA and gold particles are negatively charged, therefore efficient interaction is possible only at high salt concentration. However, unmodified particles are susceptible to aggregation at high salt concentrations. Most of the recent modification methods involve the use of surfactants or other small molecules to stabilize the nanoparticles against aggregation, enabling faster modification. Here we present our result on an alternative route to reach fast modification in low salt conditions, namely, reduction of the charge of DNA. We will discuss both the use of natural DNA under acidic pH conditions, and the use of DNA with a cationic, spermine-based “tail” which is commercially available under the name ZNA. Additionally we introduce a characterization method based on ensemble localized surface plasmon resonance measurement (LSPR) which enabled us to extract the kinetics of DNA absorbance without the need for fluorescent tags. Lastly we show that the same ZNA-based modification protocol can be effectively used for silver nanoparticle modification. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use onl

StratIT– Ein Rahmenwerk zu den Inhalten von ITStrategien. Grundlegung und methodische Fundierung

Bis heute ist kein Konsens über die Inhalte von IT-Strategien vorhan-den. Daraus folgt eine gewisse Unsicherheit, wenn es gilt, die Themenbereiche einer IT-Strategie festzulegen. Dieser Missstand soll durch den Entwurf eines Rahmenwerks/Frameworks behoben werden. Die Fachgruppe Strategisches In-formationsmanagement der Gesellschaft für Informatik (GI-Fachgruppe SIM) hat sich zum Ziel gesetzt, ein entsprechendes Rahmenwerk zu entwickeln. Dieses dient dazu, die Erstellung von IT-Strategien zu unterstützen. Der vorlie-gende Beitrag beschreibt den aktuellen Stand der Arbeit und zeigt im Sinne einer Diskussionsgrundlage auf, in welche thematischen Perspektiven, Domä-nen und Elemente sich IT-Strategien gliedern lassen. Darüber hinaus werden die methodische und wissenschaftstheoretische Fundierung sowie der „modus operandi“ der Arbeitsgruppe beschrieben. Das Rahmenwerk „StratIT“ entsteht in Zusammenarbeit von Forschern und Praktikern

Mechanosensitivity during lower extremity neurodynamic testing is diminished in individuals with Type 2 Diabetes Mellitus and peripheral neuropathy: a cross sectional study

<p>Abstract</p> <p>Background</p> <p>Type 2 Diabetes Mellitus (T2DM) and diabetic symmetrical polyneuropathy (DSP) impact multiple modalities of sensation including light touch, temperature, position sense and vibration perception. No study to date has examined the mechanosensitivity of peripheral nerves during limb movement in this population. The objective was to determine the unique effects T2DM and DSP have on nerve mechanosensitivity in the lower extremity.</p> <p>Methods</p> <p>This cross-sectional study included 43 people with T2DM. Straight leg raise neurodynamic tests were performed with ankle plantar flexion (PF/SLR) and dorsiflexion (DF/SLR). Hip flexion range of motion (ROM), lower extremity muscle activity and symptom profile, intensity and location were measured at rest, first onset of symptoms (P1) and maximally tolerated symptoms (P2).</p> <p>Results</p> <p>The addition of ankle dorsiflexion during SLR testing reduced the hip flexion ROM by 4.3° ± 6.5° at P1 and by 5.4° ± 4.9° at P2. Individuals in the T2DM group with signs of severe DSP (n = 9) had no difference in hip flexion ROM between PF/SLR and DF/SLR at P1 (1.4° ± 4.2°; paired t-test p = 0.34) or P2 (0.9° ± 2.5°; paired t-test p = 0.31). Movement induced muscle activity was absent during SLR with the exception of the tibialis anterior during DF/SLR testing. Increases in symptom intensity during SLR testing were similar for both PF/SLR and DF/SLR. The addition of ankle dorsiflexion induced more frequent posterior leg symptoms when taken to P2.</p> <p>Conclusions</p> <p>Consistent with previous recommendations in the literature, P1 is an appropriate test end point for SLR neurodynamic testing in people with T2DM. However, our findings suggest that people with T2DM and severe DSP have limited responses to SLR neurodynamic testing, and thus may be at risk for harm from nerve overstretch and the information gathered will be of limited clinical value.</p

The Role of Inflammatory Mediators in the Pathogenesis of Otitis Media and Sequelae

This review deals with the characteristics of various inflammatory mediators identified in the middle ear during otitis media and in cholesteatoma. The role of each inflammatory mediator in the pathogenesis of otitis media and cholesteatoma has been discussed. Further, the relation of each inflammatory mediator to the pathophysiology of the middle and inner ear along with its mechanisms of pathological change has been described. The mechanisms of hearing loss including sensorineural hearing loss (SNHL) as a sequela of otitis media are also discussed. The passage of inflammatory mediators through the round window membrane into the scala tympani is indicated. In an experimental animal model, an application of cytokines and lipopolysaccharide (LPS), a bacterial toxin, on the round window membrane induced sensorineural hearing loss as identified through auditory brainstem response threshold shifts. An increase in permeability of the blood-labyrinth barrier (BLB) was observed following application of these inflammatory mediators and LPS. The leakage of the blood components into the lateral wall of the cochlea through an increase in BLB permeability appears to be related to the sensorineural hearing loss by hindering K+ recycling through the lateral wall disrupting the ion homeostasis of the endolymph. Further studies on the roles of various inflammatory mediators and bacterial toxins in inducing the sensorineumral hearing loss in otitis media should be pursued

Factors Influencing Manufacturing Development in South Dakota

The general objectives of this study are two-fold: (1) To explore how the extent and type of rural industrialization being experienced in South · Dakota differs among types of communities and local labor sheds. (2) To draw policy and planning conclusions that can be used. by rural industrial development entities at the community, district, and state levels in South Dakota. To achieve these two general objectives, the following specific study objectives will be pursued: (1) To determine relationships between the magnitude of manufacturing employment growth and various community and \u27local labor shed characteristics. (2) To determine relationships between the type of manufacturing growth and various community and local labor shed characteristics. (3) To determine those location factors which can be affected by policies and programs of industrial development entities at the community, district, and state levels in South Dakota. (4) To integrate those location factors found to be significant into a viable development strategy

Comparing self-report, clinical examination and functional testing in the assessment of work-related limitations in patients with chronic low back pain

PURPOSE: To compare the work-related limitations assessed using self-report, clinical examination and functional testing in patients with chronic low back pain (CLBP). METHODS: Work-related limitations of 92 patients were assessed using self-report, clinical examination and functional testing. To obtain the assessed limitations the patient (self-report), the physician (clinical examination) and a trained evaluator (functional testing) completed a scorings form about the work-related limitations of the patient. The Isernhagen Work Systems Functional Capacity Evaluation (IWS FCE) was used to obtain the functional testing results. A kappa value of more than 0.60, absolute agreement of more than 80% and ICC of more than 0.75 were considered as acceptable. RESULTS: Little agreement and correlation among self-report, clinical examination and functional testing were found for the assessment of work-related limitations. Self-reported limitations were considerably higher than from those derived from clinical examination or functional testing. Additionally, the limitations derived from the clinical examination were higher than those derived from the IWS FCE. CONCLUSION: Comparing self-report, clinical examination and functional testing for assessing work-related limitations in CLBP patients showed large considerable differences in limitations. Professional health care workers should be aware of these differences when using them in daily practice