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81.
In this work, a novel calibration approach for minor and trace element quantification in LA-ICP-MS imaging of biological tissues is presented. Droplets of aqueous standard solutions are deposited onto pre-cut pieces of filter paper, allowed to dry, and sputtered with a thin gold layer for use as pseudo-internal standard. Analysis of the standards using LA-ICP-MS is performed using radial line-scans across the filters. In contrast to conventionally used preparation of matrix-matched tissue standards, the dried-droplet approach offers a variety of advantages: The standards are easy to prepare, no characterization of the standards using acid digestion is required, no handling of biological materials is necessary, and the concentration range, as well the number of investigated analytes is almost unlimited. The proposed quantification method has been verified using homogenized tissue standards with known analyte concentrations before being applied to a human malignant mesothelioma biopsy from a patient who had not received any chemotherapeutic treatment. Elemental distribution images were acquired at a lateral resolution of 40 μm per pixel, limits of detection ranging from 0.1 μg g−1 (Mn, Ni, Cu, Zn) to 13.2 μg g−1 (K) were reached. 相似文献
82.
Dark matter (DM) annihilations in the Sun to neutrino–antineutrino pairs are known to have potentially observable signatures in neutrino telescopes such as IceCube and KM3. We propose a model independent analysis in which the monochomatic neutrino signal from dark matter (DM) annihilations in the Sun is related to the direct detection spin-independent and spin-dependent cross sections rather than assuming cross sections from a particular model. We propagate the neutrinos from the center of the Sun to the Earth taking into account matter effects on neutrino oscillations. For DM capture in the Sun via a large spin-dependent DM capture cross section the discovery prospects of the IceCube experiment are found to be promising. 相似文献
83.
84.
85.
The metal-catalyzed allylic substitution reaction of 5a,b and 6a was examined. Reaction with stabilized nucleophiles led to exclusive attack at the less-hindered allylic terminus, and the stereoselectivity varied with the bidentate ligand used but favored retention. The yields and reaction times were improved with the use of microwaves. Alkylation via transmetalation was only observed with phenyl- and vinylstannatranes and gave regio- and stereoselectivity opposite those observed with the stabilized anions. The epimeric carbonates 5a and 5b displayed very different reactivities. Catalysts containing metals other than palladium were completely unreactive and led to recovered starting material. 相似文献
86.
L. Burnett Colin Rochester Mark Mackay Anné Proos Warwick Shaw Gabe Hegedus 《Accreditation and quality assurance》1997,2(2):76-81
The Department of Clinical Chemistry and Molecular Genetics, within the Institute of Clinical Pathology and Medical Research
at Westmead Hospital, is a medical testing laboratory operating within the public sector health system of New South Wales,
Australia. It provides acute-care pathology services to Westmead Hospital (a 900-bed tertiary referral university teaching
hospital) as well as to three district hospitals and three rural hospitals. In addition to these core clinical chemistry services,
it offers approximately 150 specialised biochemistry, pharmacology, toxicology, trace metal and molecular genetics assays
as a reference laboratory service. In 1993, the Department became Australia's first medical testing laboratory to be registered
to ISO 9001-1987/AS3901-1987. In 1995, this certification was extended to AS/NZS ISO 9001-1994. We are currently preparing
for further accreditation to ISO/IEC Guide 25-1990, with additional supplementary requirements for medical testing. This paper
describes the Quality System that the Department developed and which has been successfully maintained and extended since original
certification. Important features of the Quality System are:
1. Primary design of the Quality System to meet medical and customer needs, with subsequent addition of required ISO elements.
2. Use of national Quality Award criteria to identify key business processes.
3. Development of integrated technical non-conformance, customer complaint, staff suggestion, and quality system corrective
action procedures.
4. Implementation without external resources.
Our conclusions are that ISO 9000 Quality Systems can be applied to medical testing laboratories, and can be implemented with
minimum resource costs. Improvements in technical and service quality and business performance have resulted from this process.
However, implementation of ISO 9000 at the level of individual Departments is not ideal. Greater improvements are possible
when this process is undertaken at the level of the entire organisation.
Received: 9 September 1996 Accepted: 5 October 1996 相似文献
87.
A series of 4-substituted pyridine-capped 5,12-dioxocyclams was synthesized and fully characterized. The 4-substituent varied from electron-withdrawing groups (NO2, NO, CN) to electron-donating groups (NHCbz, NH2). The most versatile substituent was the 4-bromo group, which could be replaced by a variety of groups using Stille, Sonogashira, or Buchwald-Hartig palladium-catalyzed chemistry. Copper complexes of a majority of these capped dioxocyclams were synthesized and characterized as well. 相似文献
88.
Bernard Bennetau Denis Youhouvoulou NGabe Jacques Dunogues 《Tetrahedron letters》1985,26(32):3813-3816
Complete silylation of hexachlorobenzene using the Me3 SiCl/Li/THF reagent at O°C quantitatively affords tetrakis(trimethylsilyl)allene. This last upon a double protodesilylation with F3CCOOH at O°C, leads to the quantitative formation of 1,3-bis(trimethylsilyl) propyne via the 1,3,3-tris(trimethylsilyl)propyne. 相似文献
89.
O. F. Solomon M. Corciovei I. Gabe E. Beral 《Journal of polymer science. Part A, Polymer chemistry》1971,9(2):509-522
The polymerization of acrylic and methacrylic esters of 2-allyphenol with different anionic, cationic and coordination catalysts was studied. The polymerization occurs exclusively or predominantly through (meth)acrylic C?C double bonds in all the studied cases. With anionic catalysts the allylic groups are not polymerizable and the polymers have linear structure. Polymerization with catalysts based on dialkylaluminum chloride (alone or associated with some metal salts) yields soluble or partially crosslinked polymers, depending on the reaction conditions. The crosslinking is due to the participation of allylic groups in the polymerization reactions. Copolymers of acrylic and methacrylic esters of 2-allylphenol with styrene, acrylonitrile, methyl methacrylate, N-vinylcarbazole and 1,3-pentadiene were synthesized by copolymerization in the presence of anionic catalysts and of systems based on dialkylaluminum chloride. 相似文献
90.
Gabe Cunningham 《Discrete Mathematics》2012,312(4):763-771
The mixing operation for abstract polytopes gives a natural way to construct a minimal common cover of two polytopes. In this paper, we apply this construction to the regular convex polytopes, determining when the mix is again a polytope, and completely determining the structure of the mix in each case. 相似文献