1,722,131 research outputs found
Kekuasaan dan perilaku korupsi: Catatan hukum Saldi Isra
No full textDengan gaya bahasa yang sederhana dan gamblang, persoalan korupsi yang rumit, menggurita dan melibatkan segala segi kekuasaan diurai dengan piawai oleh Saldi Isra dalam buku ini. Pembaca akan dengan mudah memahami betapa hebatnya kampanye dan politik uang, sepak terjang hakim tindak pidana korupsi, mafia peradilan, hingga suara lembut dari istana
SALDI-MS and SERS Multimodal Imaging: One Nanostructured Substrate to Rule Them Both
No full textImaging techniques
based on mass spectrometry or spectroscopy methods
inform in situ about the chemical composition of
biological tissues or organisms, but they are sometimes limited by
their specificity, sensitivity, or spatial resolution. Multimodal
imaging addresses these limitations by combining several imaging modalities;
however, measuring the same sample with the same preparation using
multiple imaging techniques is still uncommon due to the incompatibility
between substrates, sample preparation protocols, and data formats.
We present a multimodal imaging approach that employs a gold-coated
nanostructured silicon substrate to couple surface-assisted laser
desorption/ionization mass spectrometry (SALDI-MS) and surface-enhanced
Raman spectroscopy (SERS). Our approach integrates both imaging modalities
by using the same substrate, sample preparation, and data analysis
software on the same sample, allowing the coregistration of both images.
We transferred molecules from clean fingertips and fingertips covered
with plasticine modeling clay onto our nanostructure and analyzed
their chemical composition and distribution by SALDI-MS and SERS.
Multimodal analysis located the traces of plasticine on fingermarks
and provided chemical information on the composition of the clay.
Our multimodal approach effectively combines the advantages of mass
spectrometry and vibrational spectroscopy with the signal enhancing
abilities of our nanostructured substrate
SALDI-MS of real world samples
No full textSurface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is a method of mass spectrometry, ideal for the low mass range, as it reduces fragmentation and helps with clarity of sample analysis. Projected applications of this technology can be seen in medical and drug research.
• Quinine is a small, organic biomolecule (molecular weight 325 g/mol) that is derived from the bark of the cinchona plant. Native to the Americas, is historically used as an anti-malaria, but in recent years has emerged in drug analyses of heroin. Dealers dilute the sample in quinine, which has a similar bitter taste, as a way to conserve supply.
Due to its variety of functional groups and reactive units, quinine has many side effects. As of April 2019, the FDA limits quinine to 83ppm in beverage samples. Coupled with its increased use in illegal drugs and its regulated recreational use, a new, quick and easy method of detection is needed for its analysis.
• Quinine is commonly found dissolved in carbonated beverages to make tonic water.
• Transition metal oxide (TMOs) nanoparticles are used in SALDI-MS because they require minimal sample preparation, have large surface area to sample rations (which helps with desorption/ionization), and they are compatible with a wide range of different samples
Escolar, Diego Los dones étnicos de la Nación, Identidades huarpe y modos de producción de soberanía en Argentina, Prometeo, Buenos Aires, 2007, 249 pp. Mapas, fotografías, cuadros
No full textFil: Saldi, Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin
Development of nanomaterials for SALDI-MS analysis in forensics
No full textWithin the last decade, the escalation of research output in the field of nanotechnology has spurred the development of new nanomaterials for use as assisting agents in surface assisted laser desorption ionization mass spectrometry (SALDI-MS). Specifically modified nanomaterials, coupled with mass spectrometry, have improved the detection sensitivity, specificity, flexibility and reproducibility of SALDI-MS analysis. The technological advancement of LDI-MS has in turn, propelled the use of the analytical technique in the field of forensics. In this report, the various roles and applications of metal-, silicon- and carbon-based nanostructured materials as SALDI matrices in the analysis of forensic samples are described. The advantages of SALDI-MS as an analytical tool for forensic sample analysis are also discussed
Metabolite Imaging Using Matrix-Enhanced Surface-Assisted Laser Desorption/Ionization Mass Spectrometry (ME-SALDI-MS)
No full textWe describe here the use of a hybrid ionization approach, matrix-enhanced surface-assisted laser desorption/ionization mass spectrometry (ME-SALDI-MS) in bioimaging. ME-SALDI combines the strengths of traditional matrix-assisted laser desorption/ionization (MALDI) and SALDI and enables successful MS imaging of low-mass species with improved detection sensitivity. Using 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) as the MS standard, MS performances of MALDI, SALDI, and ME-SALDI are systematically compared. The analyte desorption and ionization mechanism in ME-SALDI is qualitatively speculated based on the observation of significantly reduced matrix background and improved survival yields of molecular ions. Improvements in detection sensitivity of low-mass species using ME-SALDI over MALDI in imaging are demonstrated with mouse heart and brain tissues
Ecotoxicological impact of deactivated asbestos-cement on soil ecosystems
Full text linkThe effects of thermally deactivated asbestos cement (DAC) on the soil ecosystem were evaluated using the soil model organism Folsomia candida (Collembola). Two materials were obtained by treating asbestos cement slates, commonly used for roofing, at 1100 °C under oxidizing conditions (Red DAC) and at 1150 °C under reducing conditions (Green DAC). Ten age-synchronized juveniles of F. candida were exposed to DAC powder:soil mixtures in ratios of 1:1 and 1:10 for both types. After 28 days, adults and juveniles were counted to assess treatment effects. The results indicate distinct toxicity profiles. The Red powder did not induce adult lethality at the tested concentrations; however, a significant reduction in juvenile production was observed at the higher concentration (1:1). In contrast, the Green powder caused adult lethality at 1:1 concentration, with no juveniles produced. Both materials contain a high percentage of silica glass (∼40% by weight), a well-known insect dehydration agent and mechanical insecticide. At the highest concentration, silica glass may cause detrimental effects on juveniles, which are more sensitive to dehydration than adults. Green DAC also contains 8.5% lime (CaO), an antimicrobial and insecticidal agent that can disrupt soil pH. The combination of silica-induced dehydration and lime-mediated alkalinity may account for the lethal effects of Green DAC on F. candida adults. These findings reinforce the need for proper DAC recycling. While asbestos deactivation effectively eliminates its hazard in the built environment, improper disposal or soil contamination may pose ecological risks. Recycling DAC into stable matrices, such as ceramics or mortar, minimizes environmental contamination while promoting circular economy
A topology for team policies and existence of optimal team policies in stochastic team theory
No full textIn this paper, we establish the existence of team-optimal policies for static teams and a class of sequential dynamic teams. We first consider the static team problems and show the existence of optimal policies under certain regularity conditions on the observation channels by introducing a topology on the set of policies. Then, we consider sequential dynamic teams and establish the existence of an optimal policy via the static reduction method of Witsenhausen. We apply our findings to the well-known counterexample of Witsenhausen and the Gaussian relay channel problem
Critical stationary Kirchhoff equations in RN involving nonlocal operators
No full textIn this paper we establish existence and multiplicity of nontrivial non-negative entire (weak) solutions of a stationary Kirchhoff eigenvalue problem, involving a general nonlocal integro-differential operator. The model under consideration depends on a real parameter and involves two superlinear nonlinearities, one of which could be critical or even supercritical
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