OALib Journal期刊

ISSN: 2333-9721



匹配条件: “specificity” ,找到相关结果约873条。
Performance Characteristics of ELISA to Detect Bovine Viral Diarrhea Virus (BVDV) Antibodies Using Colostrum  [PDF]
Caitlin J. Jenvey, Andrew M. Weir, Michael P. Reichel, Peter D. Cockcroft
Open Journal of Veterinary Medicine (OJVM) , 2015, DOI: 10.4236/ojvm.2015.52006
Abstract: Colostrum contains substantially higher concentrations of immunoglobulins (Igs) when compared with serum or milk, which may improve the diagnostic sensitivity of an antibody ELISA when using colostrum. In this study, BVD was used as a model to identify the performance characteristics of colostrum and to assess the potential for increased ELISA sensitivity when compared with serum. Blood and colostrum samples were collected from cows within two dairy cattle herds: a previously infected and BVD-vaccinated Holstein-Friesian (positive herd) herd, and a bulk-tank milk antibody negative (negative herd) Jersey herd. All samples were tested using a commercial BVDV antibody ELISA. Median sample-to-positive (S/P) colostrum ratios were significantly higher than their respective serum counterparts, and positive herd S/P ratios were significantly higher than the respective negative herd values (P < 0.001). Using the manufacturer’s recommended serum dilution (1:5) and colostrum dilution (undiluted), and a cut-off threshold S/P ratio of 0.2, diagnostic sensitivity (DSe) and diagnostic specificity (DSp) for colostrum were 100% and 70%, respectively. These values increased to 100% DSe and 100% DSp with an increase in cut-off threshold S/P to 0.5. At a sample dilution of 1:100, the DSe of colostrum was 90% and significantly higher compared with serum (DSe 17%). Colostrum has the potential to improve identification of previously infected animals, either individually, or when using pooled samples.
The diagnostic accuracy of the usage of the Fetal Medicine Foundation’s (FMF) on-line risk calculator with first-trimester ultrasound for screening for preeclampsia in high-risk pregnant Brazilian population  [PDF]
Ernesto Antonio Figueiró-Filho, Maithe Vendas Galhardo, Bruno Areco de Souza
Open Journal of Obstetrics and Gynecology (OJOG) , 2012, DOI: 10.4236/ojog.2012.23063
Abstract: To evaluate the sensitivity and specificity of the usage of the FMF On-Line Risk Calculator with first-trimester ultrasound, in screening assessment for preeclampsia (PE), without serum markers. To define the best risk cut-off values for early, intermediate and late preeclampsia. Diagnostic accuracy study of pregnant women who had first-trimester ultrasounds between 11 and 13 weeks. The index test was the first-trimester ultrasound scan plus the FMF On-Line Risk Calculator to assess the risk for PE. The reference standard was the confirmation of actual development of early, intermediate or late PE. For calculations of sensitivity and specificity to determine the best cut-off values for early, intermediate and late PE, all the information was processed into ROC curves. The assessment of preeclampsia risk in the first trimester using an ultrasound plus the FMF On-Line Risk Calculator demonstrated a significant (p < 0.05) area under the ROC curve for early, intermediate and late preeclampsia. The best risk cut-off values were defined as 2.1% for early, 2.5% for intermediate and 3.5% for late preeclampsia. The first trimester US plus the FMF On-Line Risk Calculator tool was useful and applicable when assessing the risk for preeclampsia in a specific pregnant Brazilian population.
Sensitivity and specificity of five malaria rapid diagnostic kits used in south-south region of Nigeria  [PDF]
Seto Aladenika, Mirabeau Tatfeng, Gilbert Nwobu, Eguagie Osakue, Alfred Ehiaghe, Joy Imuetinya Ehiaghe, Maureen Uchechukwu Okwu, Augustina Isioma Ikusemoro
Open Journal of Clinical Diagnostics (OJCD) , 2012, DOI: 10.4236/ojcd.2012.24016
Abstract: Sensitivity and specificity of five commonly used rapid malaria test kits in South-South geopolitical zone of Nigeria were analyzed, namely Plasmotest (Biotech International, Germany), Malariatest (Acon Diagnostic, USA), AcumPF (Acumen, China), PF test (Diaspot, Indonesia) and Malaria P.f. (Global, USA). A total of 200 positive malaria blood sample using microscopy as gold standard and 200 negative were obtained from adult and children. All the kits were tested against these gold standards as directed by the manufacturers. Of the 100 positive gold standard used from children sample, 96% sensitivity were recorded for Biotech, Acon and Global 97%, while Acumen and Diaspot had 99% and 98% respectively. The the highest Specificity was recorded with Biotech 99% both Acumen and Diaspot had 97% specificity. In adult blood sample, there was general reduction in the sensitivity of the test kits. We obtained Sensitivity of 30% with Biotech, 46% with Acon, Global 73%, Diaspot 75%, and Acumen 78%. Considering the increasing influx of MRDT’s into the country, and from the result obtained from this study, there is need for control agensis to ensure that diagnostic test kits be reevaluated before introduction into Nigeria market.
In Vitro Culture of Plasmodium falciparum: Obtention of Synchronous Asexual Erythrocytic Stages  [PDF]
María Roncalés, Jaume Vidal, Pedro A. Torres, Esperanza Herreros
Open Journal of Epidemiology (OJEpi) , 2015, DOI: 10.4236/ojepi.2015.51010
Abstract: Cultivation of the erythrocytic stages of Plasmodium parasites, specifically the most important and deadly for humans, Plasmodium falciparum, has required a lot of effort and time in order to develop a continuous in vitro culture. Moreover, the development of methods to synchronize P. falciparum parasites (which grow asynchronously in vitro) has become an essential tool in research to study different immulogical, biochemical or physiological aspects of the parasite. We have compared two different synchronization methods, one based on differential permeability of the membrane of parasitized erythrocytes, and the other on the sedimentation behavior in gelatin solution. An optimized method has been established which allows for maintaining a healthy, highly synchronous culture for longer periods of time. Asexual erythrocytic stages of a complete P. falciparum cycle have been obtained, which is the starting point of the stage-specific assays of the activity of new antimalarial drugs.
A Framework for the Specificity of Addictions
Steve Sussman,Adam Leventhal,Ricky N. Bluthenthal,Marilyn Freimuth,Myriam Forster,Susan L. Ames
International Journal of Environmental Research and Public Health , 2011, DOI: 10.3390/ijerph8083399
Abstract: Research over the last two decades suggests that a wide range of substance and behavioral addictions may serve similar functions. Yet, co-occurrence of addictions has only been reported among a minority of addicts. “Addiction specificity” pertains to a phenomenon in which one pattern of addictive behaviors may be acquired whereas another is not. This paper presents the PACE model as a framework which might help explain addiction specificity. Pragmatics, attraction, communication, and expectation (PACE) variables are described, which may help give some direction to future research needs in this arena.
Development of a Specifically Enhanced Enzyme-Linked Immunosorbent Assay for the Detection of Melamine in Milk
Hongtao Lei,Rui Su,Simon A. Haughey,Qiang Wang,Zhenlin Xu,Jinyi Yang,Yudong Shen,Hong Wang,Yueming Jiang,Yuanming Sun
Molecules , 2011, DOI: 10.3390/molecules16075591
Abstract: An indirect competitive enzyme-linked immunosorbent assay (icELISA) with enhanced specificity for melamine in milk was developed. Three haptens of melamine with different spacer-arms were used to prepare different plate coating antigens. It was found that the icELISA show best sensitivity and specificity to melamine when using the coating antigen prepared by coupling 3-(4,6-diamino-1,6-dihydro-1,3,5-triazin-2-ylthio)propanoic acid (Hapten C) with ovalbumin (OVA). The 50% inhibitory concentration (IC50) value was 35.4 ng·mL?1, the limit of detection (LOD) was 8.9 ng·mL?1 and the detectable working range (20–80% inhibitory concentration) was from 14.9 to 108.5 ng·mL?1, respectively. Compared to the ELISA results previously reported, the developed icELISA in the present study showed a much lower cross-reactivity to cyromazine, a fly-killing insecticide widely used in vegetables and stables. Recoveries obtained from milk samples in this study were in agreement with those obtained using the HPLC-MS method, indicating the detection performance of the icELISA could meet the requirement of the residue limit set by the Codex Alimentarius Commission. Therefore, the developed immunoassay can be applied for the analysis of melamine presented in milk.
Síntese de esteres terpenóides por via enzimática: influência do tamanho da cadeia alifática do ácido graxo e da estrutura do álcool de terpeno
CASTRO, Heizir F.;OLIVEIRA, Pedro C.;SOARES, Cleide, M.F.;
Ciência e Tecnologia de Alimentos , 1997, DOI: 10.1590/S0101-20611997000300006
Abstract: the selectivity of a commercial immobilized lipase preparation was tested in two set of esterification reactions. in the first group, synthesis were carried out with citronellol and different organic acids (c2 to c18). for this case, with the exception of acetic acid, the size of the carbon chain showed no significant alteration in the esterification rates. acids containing four or more carbons, were considered to be excellent acyl donors, resulting in the esterification rates in the range of 95% to 98%. alternatively, the esterification reactions were carried out with different terpen alcohols and butyric acid. the alcohol structure showed to have great influence on the performance of this enzyme preparation. esterification degree over 95% were attained for primary alcohols such as citronellol, geraniol and nerol. secondary (menthol) and tertiary (linallol) were not esterified under the tested conditions.
Eficacia diagnóstica de la prueba cutánea de Prick con extractos alergénicos de ácaros en pacientes asmáticos
Ross Pe?a,Arlenis; Rodríguez Pérez,Judit; Pérez Fabelo,Marlene; Sarduy Ramos,Carlos M;
Revista Archivo M??dico de Camag??ey , 2009,
Abstract: background: the diagnosis of the allergic disease is based fundamentally on the clinical history and it is facilitated by diagnostic tests designed to the effect, different methods are used, inside these the named cutaneous tests of immediate reading, one of them, the test for cutaneous puncture or prick test objective: to evaluate the validity and security of prick test with extract of mites in asthmatic patients. method: a diagnostic controlled, randomized clinical assay was performed, the sample was constituted by 100 patients with antecedents of bronchial asthma diagnosed in any moment of their lives that came to the allergology consultation at the "manuel ascunce domenech" provincial university hospital of camagüey city from september 2006 to july 2007, and 100 healthy volunteers that conformed the control group; to everyone were carried out, previous informed consent, duplicate cutaneous tests with allergenic extracts of dermatophagoides pteronyssinus, dermatophagoides siboney and blomia tropicalis produced in the biopreparation national center, to a concentration of 20 000 ub / ml. results: the prevalence of the bronchial asthma in the feminine sex and in ages between 15 and 38 years. allergic rinitis was the disease associated to asthma with more frequency. dermatophagoides pteronyssinus was the mite of higher prevalence and whelk diameter in prick test. conclusions: the prick cutaneous test with mite extracts was effective in patients with bronchial asthma.
Intera??o de bactérias fluorescentes do gênero Pseudomonas e de Bacillus spp. com a rizosfera de diferentes plantas
Coelho, Luciana Fontes;Freitas, Sueli dos Santos;Melo, Arlete Marchi Tavares de;Ambrosano, Gláucia Maria Bovi;
Revista Brasileira de Ciência do Solo , 2007, DOI: 10.1590/S0100-06832007000600018
Abstract: despite numerous reports on plant growth-promoting rhizobacteria (pgpr), there are few of them explaining their mode of action. it is possible that some plants promote bacterial colonization in the rhizosphere to facilitate plant-bacterium interaction, as if there were a certain mutual specificity. the objective of this study was to verify if lettuce plants promote root colonization by fluorescent pseudomonads, in comparison with other plants and with bacillus spp. roots of lettuce and some other vegetables were sampled in different properties of small commercial producers in campinas-sp, brazil. colony forming units (cfu) of fluorescent pseudomonads and bacillus spp. were counted by serial dilution and plating. the numbers of fluorescent pseudomonads were significantly higher in lettuce rhizosphere than in other plants, unlike the numbers of bacillus spp.
Declínio de desempenho motor no envelhecimento é específico à tarefa
Teixeira, Luís Augusto;
Revista Brasileira de Medicina do Esporte , 2006, DOI: 10.1590/S1517-86922006000600010
Abstract: decline of motor performance characteristically observed in the aging process has been proposed to be caused by a single factor: deterioration of the central information processing capacity. if so, motor performance in different tasks should decline in a similar way as an individual gets older. in order to test this hypothesis, motor performance of 19- to 73-years-old physical active individuals was studied in eight motor tasks: reaction time, movement time in aiming, handgrip strength, anticipatory timing, force control, repetitive tapping, sequential drawing and sequential fingers movements. the analysis indicated a diversity of performance profiles between tasks across ages, with motor decline at a moderate rate between 20 and 60 years for reaction time, larger performance decline in the transitions between 20 and 40 years in tasks requiring movement speed in simple movements or temporal accuracy, larger decline in the transition between 60 and 70 years for maximum manual strength and graphic skill, and stable performance across ages for manual force control. therefore, these results are contradictory to the single factor hypothesis, offering support for the alternative hypothesis of task-specific decline of sensorimotor performance as a function of aging.

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