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排序方式: 共有105条查询结果,搜索用时 31 毫秒
91.
Noordegraaf D Skovgaard PM Sandberg RH Maack MD Bland-Hawthorn J Lawrence JS Lægsgaard J 《Optics letters》2012,37(4):452-454
We demonstrate efficient multimode (MM) to single-mode (SM) conversion in a 19-port photonic lantern with a 50 μm core MM delivery fiber. The photonic lantern can be used within the field of astrophotonics for coupling MM starlight to an ensemble of SM fibers in order to perform fiber-Bragg-grating-based spectral filtering. An MM delivery fiber spliced to the photonic lantern offers the advantage that the delivery fiber guides the light from the focal plane of the telescope to the splitter. Therefore, it is no longer necessary to have the splitter mounted directly in the focal plane of the telescope. The coupling loss from a 50 μm core MM fiber to an ensemble of 19 SM fibers and back to a 50 μm core MM fiber is below 1.1 dB. 相似文献
92.
Because immunoassay responds to epitopes, and many molecules share the same peptide epitope, it is very difficult to obtain an accurate understanding of peptides, their creation and hydrolysis, in biological systems. Separate-and-detect approaches have merit in that the many active peptides and inactive fragments of a particular system can be separately determined. This review discusses the separation, by chromatography and capillary electrophoresis, and detection, by absorbance, fluorescence, electrochemistry, and immunoassay techniques. When separation pre-concentration is accompanied by laser-induced fluorescence or biuret-based electrochemical detection, nM-pM detection limits are obtained. 相似文献
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95.
Rhoda Elison Hirsch Margaret J. Lin Usha Rao Pulakhandam Ronald L. Nagel Sverre Sandberg 《Photochemistry and photobiology》1993,57(5):885-888
Abstract— Whole blood and hemolysates from seven normal and three erythropoietic protoporphyria patients were compared in terms of their hemoglobin function. The oxygen affinity (P50 ) of the erythropoietic protoporphyria hemolysates compared to normals (13.1 ± 0.2 vs 17.5 ± 0.3 mmHg; P < 0.001) and erythropoietic protoporphyria erythrocytes compared to normals (23.4 ± 0.6 vs 27.1 ± 0.5 mmHg; P < 0.001) were increased while oxygen-binding cooperativity (n-value of the Hill equation) were similar. We conclude that hemoglobin function in erythropoietic protoporphyria patients is altered, but without pathophysiologic consequences. Because hemoglobin in which protoporphyrin IX substitutes for heme has a low oxygen affinity, our findings of a higher than normal affinity in erythropoietic protoporphyria red cells and hemolysates may indirectly support the findings by others that protoporphyrin IX binds to hemoglobin at non-heme-binding sites. In addition, based on the effect of other abnormal hemoglobins, this shift in P50 will decrease any tendency for anemia in erythropoietic protoporphyria patients. 相似文献
96.
A column liquid chromatographic method is presented for the determination of trace levels of acidic sulphur-containing amino acids and gamma-glutamyl di- and tripeptides in microdialysates sampled from rat brain in vivo. Automated precolumn derivatization was performed with o-phthaldialdehyde-beta-mercaptoethanol. The derivatives were separated by reversed-phase liquid chromatography with electrochemical and fluorescence detection. The mean relative standard deviation (n = 10) was 1.03 and 4.59% for retention times and peak heights, respectively. The mean correlation coefficient of linearity (r) was 0.9982 in the range 4.5-450 pmol (n = 15), and the lowest detectable amount was 200 fmol for the homocysteinesulphinic acid derivative, (k' = 5.4, at a signal-to-noise ratio of 3). A microcolumn electrochemical detection method, developed for volume-limited samples, produced a fifteen-fold increase in mass sensitivity. Neurochemical applications using microdialysis in vivo are presented. 相似文献
97.
S Sandberg W Oosterhuis D Freedman T Kawai 《Journal of the International Federation of Clinical Chemistry》1997,9(4):154-155
Each year a vast number of biomedical articles and books are published and based on the articles reviews are written. Such reviews should be performed in a systematic manner. Systematic reviewing is a new discipline with its own methods for locating, appraising, and summarizing primary studies. Such methods have also been developed for studies on diagnostic test evaluations. It is important for the laboratory disciplines to engage in this work. IFCC has established a Committee for Systematic Reviewing in Laboratory Medicine. This committee will work to promote the understanding, the use and the performance of systematic reviewing. 相似文献
98.
Athanassopoulos C Auerbach LB Burman RL Cohen I Caldwell DO Dieterle BD Donahue JB Eisner AM Fazely A Federspiel FJ Garvey GT Gray M Gunasingha RM Imlay R Johnston K Kim HJ Louis WC Majkic R Margulies J McIlhany K Metcalf W Mills GB Reeder RA Sandberg V Smith D Stancu I Strossman W Tayloe R VanDalen GJ Vernon W Wadia N Waltz J Wang YX White DH Works D Xiao Y Yellin S 《Physical review letters》1996,77(15):3082-3085
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100.
Bearden IG Beavis D Besliu C Budick B Bøggild H Chasman C Christensen CH Christiansen P Cibor J Debbe R Enger E Gaardhøje JJ Germinario M Hagel K Hansen O Holm A Holme AK Ito H Jipa A Jundt F Jørdre JI Jørgensen CE Karabowicz R Kim EJ Kozik T Larsen TM Lee JH Lee YK Løvhøiden G Majka Z Makeev A Mikelsen M Murray M Natowitz J Nielsen BS Norris J Olchanski K Ouerdane D Płaneta R Rami F Ristea C Röhrich D Samset BH Sandberg D Sanders SJ Scheetz RA Staszel P Tveter TS Videbaek F Wada R Yin Z 《Physical review letters》2004,93(10):102301
Transverse momentum spectra and rapidity densities, dN/dy, of protons, antiprotons, and net protons (p-p) from central (0%-5%) Au+Au collisions at square root of S(NN)=200 GeV were measured with the BRAHMS experiment within the rapidity range 0=y=3. The proton and antiproton dN/dy decrease from midrapidity to y=3. The net-proton yield is roughly constant for y<1 at dN/dy approximately 7, and increases to dN/dy approximately 12 at y approximately 3. The data show that collisions at this energy exhibit a high degree of transparency and that the linear scaling of rapidity loss with rapidity observed at lower energies is broken. The energy loss per participant nucleon is estimated to be 73+/-6 GeV. 相似文献