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Single Instrument (single + instrument)
Selected AbstractsProof of principle: An HIV p24 microsphere immunoassay with potential application to HIV clinical diagnosis,CYTOMETRY, Issue 3 2009Pascale Ondoa Abstract The measurement of CD4 counts and viral loads on a single instrument such as an affordable flow cytometer could considerably reduce the cost related to the follow-up of antiretroviral therapy in resource-poor settings. The aim of this study was to assess whether the HIV-1 p24 antigen could be measured using a microsphere-based flow cytometric (FC) assay and the experimental conditions necessary for processing plasma samples. A commercial anti-p24 antibody pair from Biomaric was used to develop a p24 microsphere immunoassay (MIA) using HIV culture supernatant as the source of antigen. The ultrasensitive Perkin Elmer enzyme immunoassay (EIA) served as a reference assay. Quantification of HIV p24 using the heat-mediated immune complex disruption format described for plasma samples was feasible using the Biomaric MIA and applicable to a broad range of HIV-1 Group M subtypes. The inclusion of a tyramide amplification step was successful and increased the fluorescence signal up to 3 logs as compared with the MIA without amplification. The analytical sensitivity of this ultrasensitive Biomaric assay reached 1 pg/mL, whereas the ultrasensitive Perkin Elmer EIA was sensitive to less than 0.17 pg/mL. Our data indicate, for the first time, that the principle of p24 detection using the heat-denatured ultrasensitive format can be applied to FC. © 2008 Clinical Cytometry Society [source] Electron Energy Loss SpectroscopyIMAGING & MICROSCOPY (ELECTRONIC), Issue 2 2007Chemical Information at the Nanometer Scale Abstract The combination of high resolution imaging with energy loss spectroscopy allows to resolve questions about the morphology, structure, composition and electronic structure of a material in a single instrument. By the assistance of band structure calculations and simulated EELS spectra, the experimental data can be analyzed in detail. Following this approach it is possible to study the relation between the geometric and electronic structure of materials at the nanometer scale. [source] PREDICTING SENSORY COHESIVENESS, HARDNESS AND SPRINGINESS OF SOLID FOODS FROM INSTRUMENTAL MEASUREMENTSJOURNAL OF TEXTURE STUDIES, Issue 2 2008R. DI MONACO ABSTRACT The sensory evaluation of cohesiveness, hardness and springiness of 15 solid food samples was performed by eight trained assessors. The rheologic response of the 15 samples was estimated by performing cyclic compression tests and stress,relaxation tests. From the force,deformation curves of the first two cycles of the compression test, texture profile analysis parameters related to cohesiveness, hardness and springiness were calculated. Young's modulus (E), strain (di) and stress (si) at peak as well as irrecoverable strain (ri) and irrecoverable work (Li) were monitored during the first five cycles. From the stress,relaxation response, Peleg's linearization model parameters, K1 and K2, were estimated by best-fit regression. These parameters were used for predicting sensory attributes. Hardness and springiness were both accurately predicted by rheologic properties, while cohesiveness prediction was less representative. PRACTICAL APPLICATIONS This study contributes to enhance the knowledge in the research area of sensory instrumental correlation. Also, the research allows to better understanding that no single instrument is able to measure all texture attributes adequately. In fact, the results demonstrate that both stress,relaxation and cyclic compression tests need to be performed for the correct prediction of sensory responses. [source] 5-in-1 biodiesel: an approach to combining five biodiesel gas chromatographic methods on a single instrumentBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 3 2009James D. McCurry James D. McCurry and Wesley Norman report on a new technology developed at Agilent Technologies. A small external, isothermal, capillary-column oven is used to isolate a polar wax column from a high-temperature column on a single gas chromatograph (GC). This allows five different biodiesel methods to reside on the same GC which would otherwise require two separate instruments. The isothermal biodiesel methods are used to test the external column oven performance and demonstrate the ability to combine these methods on a single GC. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Review of singleton fetal and neonatal deaths associated with cranial trauma and cephalic delivery during a national intrapartum-related confidential enquiryBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 5 2005Fidelma O'Mahony Objective To review delivery details of intrapartum-related fetal and neonatal deaths with singleton cephalic presentation and birthweight of 2500 g or more in which traumatic cranial or cervical spine injury or substantial difficulty at delivery of the head was a dominant feature. Design Review of freestyle summary reports and standard questionnaire responses submitted to the national secretariat for the Confidential Enquiry into Stillbirths and Death in Infancy (CESDI) during the 1994/1995 intrapartum-related mortality enquiry following regional multidisciplinary panel review. Setting United Kingdom. Sample Of the 873 cases of intrapartum-related deaths reported in the 1994,1995 national enquiry, 709 weighed more than 2499 g. Reports from 181 (89 from 1994 and 92 from 1995) with a chance of meeting criteria for cranial or cervical trauma as significant contributors to death were examined in detail. Thirty-seven were judged to meet the criteria stated in the objectives (23 from 1994 and 14 from 1995) and form the basis for this review. Methods Electronic and hand search of CESDI records relating to intrapartum-related deaths. Main outcome measures Intrapartum events and features of care. Results There was evidence of fetal compromise present before birth in 33 of the 37 (89%) study group cases reviewed. One delivery was performed vaginally without instrumentation, and in one there was no attempt at vaginal delivery before caesarean section (CS) in the second stage of labour. Twenty-four cases (65%) were delivered vaginally and 11 (30%) by CS after failure to deliver vaginally with instruments. A single instrument was used in six cases of vaginal delivery (four ventouse and two Kjelland's forceps). At least two separate attempts with different instruments were made in 24 cases. Overall, the ventouse was used in 27 cases and forceps in 29 cases. In six cases, three separate attempts were made with at least two different instruments, all of which included use of ventouse. The grade of operator was recorded in 27 cases. Of these, a consultant obstetrician was present at only one delivery and no consultant was recorded to have made the first attempt to deliver a baby. In six cases, shoulder dystocia was also reported. Conclusions This study suggests a lower incidence of death from difficult cephalic delivery and cranial trauma than previously reported. The CESDI studies were believed to have achieved high levels of ascertainment for all intrapartum-related deaths from which the cases reported here were selected. Strictly applied entry criteria used in this study could have restricted the number of cases considered as could limited in vivo or postmortem investigations and lack of detailed autopsy. When cranial traumatic injury was observed, it was almost always associated with physical difficulty at delivery and the use of instruments. The use of ventouse as the primary or only instrument did not prevent this outcome. Some injuries occurred apparently without evidence of unreasonable force, but poorly judged persistence with attempts at vaginal delivery in the presence of failure to progress or signs of fetal compromise were the main contributory factor regardless of which instruments were used. [source] | |||||||||||||