Metallic Nanoparticles Generation by Repetitive Pulsed Laser for Applications in Bio-Medicine

A Nd:YAG pulsed laser operating at the 1064 nm wavelength, the 3 ns pulse duration, the 1010 W/cm2 intensity and the 10 Hz repetition rate is employed to irradiate biocompatible metallic targets based on Au, Bi and Ag placed in water. The laser-matter interaction produces nanometric spherical particles. The concentration of the solution with nanoparticles is controllable by the laser parameters, the ablative emission process, the irradiation time and the water’s volume. Generally, nanoparticles of about 10 nm in size and concentrations of the order (0.1 ÷ 10) mg/ml are prepared to be injected in cell cultures or in living systems (mice). The nanoparticles introduction in the extra and intra cellular liquids improves the bio-imaging of the tissue and organs by using fluorescence techniques. Moreover, if these nanoparticles are concentrated in tumour cells, they make possible high efficiency radio-therapy and thermal-therapy treatments, as it will be presented and discussed

Seeking Synchronicity: Revelations and Recommendations for Virtual Reference

A new membership report from OCLC Research, in partnership with Rutgers, the State University of New Jersey, Seeking Synchronicity distills more than five years of virtual reference (VR) research into a readable summary that features memorable quotes that vividly illustrate very specific and actionable suggestions. Taken from a multi-phase research project that included focus group interviews, surveys, transcript analysis, and phone interviews, with VR librarians, users, and non-users, these findings are meant to help practitioners develop and sustain VR services and systems. The report asserts that the "R" in "VR" needs to emphasize virtual "Relationships" as well as "Reference".Among the topics addressed are:The exaggerated death of ready referenceThe importance of query clarification in VRWays to boost accuracy and build better interpersonal relationships in VRWhat can be learned from VR transcriptsHow convenience is the "hook" that draws users into VR servicesGenerational differences in how people perceive reference interactions and determine successThe need for more and better marketingThe report is based on a multi-year study funded by the Institute of Museum and Library Services (IMLS); Rutgers, The State University of New Jersey; and OCLC. A rich resource for further exploration of this important topic, it includes valuable statistics, lists of references, additional readings, and specific recommendations for what libraries and librarians can do to move VR forward in local environments.Today's students, scholars and citizens are not just looking to libraries for answers to specific questions—they want partners and guides in a life long information-seeking journey. By transforming VR services into relationship-building opportunities, libraries can leverage the positive feelings people have for libraries in a crowded online space where the biggest players often don't have the unique experience and specific strengths that librarians offer

Service sea change: clicking with screenagers through virtual reference

Web-based reference services such as synchronous, (chat reference or \u27Ask-a-Librarian\u27 services) and asynchronous (email) virtual reference services (VRS) have become common features of academic library home pages. In the current economic and technological environment, evaluation to determine the sustainability of VRS is crucial. An international research project, funded by the Institute of Museum and Library Services, Rutgers, The State University of New Jersey, and OCLC Online Computer Library Center, Inc., investigates factors that influence the selection and use of synchronous VRS. This study, one of the first large-scale VRS studies to include both users and non-users of the Millennial Generation, innovatively addresses issues concerning the evaluation, sustainability, and relevance of VRS for academic libraries by soliciting screenagers\u27 perceptions. Three focus group interviews were conducted with "screenagers" - twelve to eighteen year-old non-users of VRS. These potential future academic library users are comfortable in a virtual environment, use instant messaging (IM) for socializing and collaborative homework yet perceive VRS differently than these other virtual encounters. The results of these focus group interviews provide new insights to why screenagers choose not to use VRS and what would make them try VRS. The study identifies ways to increase the visibility and use of VRS, and to improve service, which could help secure funding allocations, and the growth and improvement of services. These results can influence the development of academic library services and systems for the Millennial Generation

Nanoparticles: Production, Characterization and Applications

The production of metallic nanoparticles using pulsed laser ablation in water is presented. The physical characterization of the produced nanoparticles is reported in terms of electronic microscopy, optical and mechanical properties, SPR, EDX, XPS and XRD spectroscopies. The applications of the prepared nanoparticles involve different scientific fields. In particular will be discussed their use to modify some properties of polymers, liquids and alloys. Special attention is devoted to the use of nanoparticles for polymeric laser welding, to the use as an image contrast medium in the biological environment and to the use of Au-NPs targeting for radiotherapy of cancer tissues

Optical and electronic properties of manganese thiophosphate and H2T4 porphyrin metal complexes films

Films of manganese thiophosphate (MnPS3) and Mn(III)T4 porphyrin, obtained from a reaction of a colloidal suspension of MnPS3 nanosheets with an aqueous solution of the porphyrin, have been investigated by means of optical absorption and X-ray photoemission spectroscopies. Our attention is turned to the (300–850) nm range and to the C and N 1s, Mn, P, S and Cl 2p and Mn 3p core regions. The analysis of the resulting spectra and their comparison with those reported for the original compounds has allowed us to obtain information both about the interaction between MnPS3 and Mn(III)T4 and the effects produced by the porphyrin metallation

M13 phages uptake of gold nanoparticles for radio-and thermal-therapy and contrast imaging improvement

The presented work deals with the uptake of gold nanoparticles (Au NPs) by M13 phages in solutions. In particular, the Au NPs uptake modalities and their localization in the filamentous phages are evaluated and measured. Gold spherical nanoparticles (with an average diameter of the order of 10 nm) are obtained by laser ablation in water with a sodium citrated surfactant. The interest of such application comes from the possibility to employ living biological structures to transport heavy metallic nanoparticles inside cells of tumoral tissues. Indeed, phages have the capability to introduce Au NPs in the proximity to the cell nucleus, increasing the efficiency of DNA destruction in the tumoral cells by employing low doses of ionizing radiation during radiotherapy and hyperthermia treatments. Several analyses and microscopy characterizations of the prepared phages samples embedding gold nanoparticles are presented, demonstrating that the presence of Au NPs increases the phages imaging contrast

Protons accelerated in the target normal sheath acceleration regime by a femtosecond laser

Advanced targets based on thin films of graphene oxide covered by metallic layers have been irradiated at high laser intensity (∼1019 W/cm2) with 40 fs laser pulses to investigate the forward ion acceleration in the target normal sheath acceleration regime. A time-of-flight technique was employed with silicon-carbide detectors and ion collectors as fast on-line plasma diagnostics. At the optimized conditions of the laser focus position with respect to the target surface was measured the maximum proton energy using Au metallic films. A maximum proton energy of 2.85 MeV was measured using the Au metallization of 200 nm. The presence of graphene oxide facilitates the electron crossing of the foil minimizing the electron scattering and increasing the electric field driving the ion acceleration. The effect of plasma electron density control using the graphene oxide is presented and discussed

The use of pulse-compression thermography for detecting defects in paintings

Interest in the conservation of paintings grows year by year. Their periodic inspection is essential for their conservation over the time. Thermographic non-destructive inspection is one technique useful for paintings, but it is essential to be able to detect buried defects while minimising the level of thermal stimulus. This paper describes a pulse-compression infrared thermography technique whereby defect detection is optimized while minimising the rise in temperature. To accomplish this task, LED lamps driven by a coded waveform based on a linear frequency modulated chirp signal have been used on paintings on both a wooden panel and a canvas layer. These specimens contained artificially fabricated defects. Although the physical condition of each painting was different, the experimental results show that the proposed signal processing procedure is able to detect defects using a low temperature contrast