20 resultados para bench scale test
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
BACKGROUND The variant Creutzfeldt-Jakob disease incidence peaked a decade ago and has since declined. Based on epidemiologic evidence, the causative agent, pathogenic prion, has not constituted a tangible contamination threat to large-scale manufacturing of human plasma-derived proteins. Nonetheless, manufacturers have studied the prion removal capabilities of various manufacturing steps to better understand product safety. Collectively analyzing the results could reveal experimental reproducibility and detect trends and mechanisms driving prion removal. STUDY DESIGN AND METHODS Plasma Protein Therapeutics Association member companies collected more than 200 prion removal studies on plasma protein manufacturing steps, including precipitation, adsorption, chromatography, and filtration, as well as combined steps. The studies used a range of model spiking agents and bench-scale process replicas. The results were grouped based on key manufacturing variables to identify factors impacting removal. The log reduction values of a group are presented for comparison. RESULTS Overall prion removal capacities evaluated by independent groups were in good agreement. The removal capacity evaluated using biochemical assays was consistent with prion infectivity removal measured by animal bioassays. Similar reduction values were observed for a given step using various spiking agents, except highly purified prion protein in some circumstances. Comparison between combined and single-step studies revealed complementary or overlapping removal mechanisms. Steps with high removal capacities represent the conditions where the physiochemical differences between prions and therapeutic proteins are most significant. CONCLUSION The results support the intrinsic ability of certain plasma protein manufacturing steps to remove prions in case of an unlikely contamination, providing a safeguard to products.
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OBJECTIVES Cognitive fluctuation (CF) is a common feature of dementia and a core diagnostic symptom for dementia with Lewy bodies (DLB). CF remains difficult to accurately and reliably detect clinically. This study aimed to develop a psychometric test that could be used by clinicians to facilitate the identification of CF and improve the recognition and diagnosis of DLB and Parkinson disease, and to improve differential diagnosis of other dementias. METHODS We compiled a 17-item psychometric test for identifying CF and applied this measure in a cross-sectional design. Participants were recruited from the North East of England, and assessments were made in individuals' homes. We recruited people with four subtypes of dementia and a healthy comparison group, and all subjects were administered this pilot scale together with other standard ratings. The psychometric properties of the scale were examined with exploratory factor analysis. We also examined the ability of individual items to identify CF to discriminate between dementia subtypes. The sensitivity and specificity of discriminating items were explored along with validity and reliability analyses. RESULTS Participants comprised 32 comparison subjects, 30 people with Alzheimer disease, 30 with vascular dementia, 29 with DLB, and 32 with dementia associated with Parkinson disease. Four items significantly discriminated between dementia groups and showed good levels of sensitivity (range: 78.6%-80.3%) and specificity (range: 73.9%-79.3%). The scale had very good levels of test-retest (Cronbach's alpha: 0.82) and interrater (0.81) reliabilities. The four items loaded onto three different factors. These items were: 1) marked differences in functioning during the daytime; 2) daytime somnolence; 3) daytime drowsiness; and 4) altered levels of consciousness during the day. CONCLUSIONS We identified four items that provide valid, sensitive, and specific questions for reliably identifying CF and distinguishing the Lewy body dementias from other major causes of dementia (Alzheimer disease and vascular dementia).
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This study analyzed the influence of the occupational context on the conceptualization of career satisfaction measured by the career satisfaction scale (CSS). In a large sample of N ¼ 729 highly educated professionals, a cross-occupational (i.e., physicians, economists, engineers, and teachers) measurement invariance analysis showed that the CSS was conceptualized according to occupational group membership, that is, 4 of the 5 items of the scale showed measurement noninvariance. More specifically, the relative importance, the response biases, and the reliabilities associated with different career satisfaction content domains measured by the CSS (i.e., achieved success, overall career goals, goals for advancement, goals for income, and goals for development of new skills) varied by occupational context. However, results of a comparison between manifest and latent mean differences between the occupational groups revealed that the observed measurement noninvariance did not affect the estimation of mean differences.
Resumo:
Organisms provide some of the most sensitive indicators of climate change and evolutionary responses are becoming apparent in species with short generation times. Large datasets on genetic polymorphism that can provide an historical benchmark against which to test for recent evolutionary responses are very rare, but an exception is found in the brown-lipped banded snail (Cepaea nemoralis). This species is sensitive to its thermal environment and exhibits several polymorphisms of shell colour and banding pattern affecting shell albedo in the majority of populations within its native range in Europe. We tested for evolutionary changes in shell albedo that might have been driven by the warming of the climate in Europe over the last half century by compiling an historical dataset for 6,515 native populations of C. nemoralis and comparing this with new data on nearly 3,000 populations. The new data were sampled mainly in 2009 through the Evolution MegaLab, a citizen science project that engaged thousands of volunteers in 15 countries throughout Europe in the biggest such exercise ever undertaken. A known geographic cline in the frequency of the colour phenotype with the highest albedo (yellow) was shown to have persisted and a difference in colour frequency between woodland and more open habitats was confirmed, but there was no general increase in the frequency of yellow shells. This may have been because snails adapted to a warming climate through behavioural thermoregulation. By contrast, we detected an unexpected decrease in the frequency of Unbanded shells and an increase in the Mid-banded morph. Neither of these evolutionary changes appears to be a direct response to climate change, indicating that the influence of other selective agents, possibly related to changing predation pressure and habitat change with effects on micro-climate.
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The aim of this study was to refine a multi-dimensional scale based on physiological and behavioural parameters, known as the post abdominal surgery pain assessment scale (PASPAS), to quantify pain after laparotomy in horses. After a short introduction, eight observers used the scale to assess eight horses at multiple time points after laparotomy. In addition, a single observer was used to test the correlation of each parameter with the total pain index in 34 patients, and the effect of general anaesthesia on PASPAS was investigated in a control group of eight horses. Inter-observer variability was low (coefficient of variation 0.3), which indicated good reliability of PASPAS. The correlation of individual parameters with the total pain index differed between parameters. PASPAS, which was not influenced by general anaesthesia, was a useful tool to evaluate pain in horses after abdominal surgery and may also be useful to investigate analgesic protocols or for teaching purposes.
Resumo:
The objectives of this study were to develop and validate a tool for assessing pain in population-based observational studies and to develop three subscales for back/neck, upper extremity and lower extremity pain. Based on a literature review, items were extracted from validated questionnaires and reviewed by an expert panel. The initial questionnaire consisted of a pain manikin and 34 items relating to (i) intensity of pain in different body regions (7 items), (ii) pain during activities of daily living (18 items) and (iii) various pain modalities (9 items). Psychometric validation of the initial questionnaire was performed in a random sample of the German-speaking Swiss population. Analyses included tests for reliability, correlation analysis, principal components factor analysis, tests for internal consistency and validity. Overall, 16,634 of 23,763 eligible individuals participated (70%). Test-retest reliability coefficients ranged from 0.32 to 0.97, but only three coefficients were below 0.60. Subscales were constructed combining four items for each of the subscales. Item-total coefficients ranged from 0.76 to 0.86 and Cronbach's alpha were 0.75 or higher for all subscales. Correlation coefficients between subscales and three validated instruments (WOMAC, SPADI and Oswestry) ranged from 0.62 to 0.79. The final Pain Standard Evaluation Questionnaire (SEQ Pain) included 28 items and the pain manikin and accounted for the multidimensionality of pain by assessing pain location and intensity, pain during activity, triggers and time of onset of pain and frequency of pain medication. It was found to be reliable and valid for the assessment of pain in population-based observational studies.
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Fragmentation and vegetative regeneration from small fragments may contribute to population expansion, dispersal and establishment of new populations of introduced plants. However, no study has systematically tested whether a high capacity of vegetative regeneration is associated with a high degree of invasiveness. For small single-node fragments, the presence of internodes may increase regeneration capacity because internodes may store carbohydrates and proteins that can be used for regeneration. We conducted an experiment with 39 stoloniferous plant species to examine the regeneration capacity of small, single-node fragments with or without attached stolon internodes. We asked (1) whether the presence of stolon internodes increases regeneration from single-node fragments, (2) whether regeneration capacity differs between native and introduced species in China, and (3) whether regeneration capacity is positively associated with plant invasiveness at a regional scale (within China) and at a global scale. Most species could regenerate from single-node fragments, and the presence of internodes increased regeneration rate and subsequent growth and/or asexual reproduction. Regeneration capacity varied greatly among species, but showed no relationship to invasiveness, either in China or globally. High regeneration capacity from small fragments may contribute to performance of clonal plants in general, but it does not appear to explain differences in invasiveness among stoloniferous clonal species
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Background: To detect attention deficit hyperactivity disorder (ADHD) in treatment seeking substance use disorders (SUD) patients, a valid screening instrument is needed. Objectives: To test the performance of the Adult ADHD Self-Report Scale V 1.1(ASRS) for adult ADHD in an international sample of treatment seeking SUD patients for DSM-IV-TR; for the proposed DSM-5 criteria; in different subpopulations, at intake and 1–2 weeks after intake; using different scoring algorithms; and different externalizing disorders as external criterion (including adult ADHD, bipolar disorder, antisocial and borderline personality disorder). Methods: In 1138 treatment seeking SUD subjects, ASRS performance was determined using diagnoses based on Conner's Adult ADHD Diagnostic Interview for DSM-IV (CAADID) as gold standard. Results: The prevalence of adult ADHD was 13.0% (95% CI: 11.0–15.0%). The overall positive predictive value (PPV) of the ASRS was 0.26 (95% CI: 0.22–0.30), the negative predictive value (NPV) was 0.97 (95% CI: 0.96–0.98). The sensitivity (0.84, 95% CI: 0.76–0.88) and specificity (0.66, 95% CI: 0.63–0.69) measured at admission were similar to the sensitivity (0.88, 95% CI: 0.83–0.93) and specificity (0.67, 95% CI: 0.64–0.70) measured 2 weeks after admission. Sensitivity was similar, but specificity was significantly better in patients with alcohol compared to (illicit) drugs as the primary substance of abuse (0.76 vs. 0.56). ASRS was not a good screener for externalizing disorders other than ADHD. Conclusions: The ASRS is a sensitive screener for identifying possible ADHD cases with very few missed cases among those screening negative in this population.
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Safe disposal of toxic wastes in geologic formations requires minimal water and gas movement in the vicinity of storage areas, Ventilation of repository tunnels or caverns built in solid rock can desaturate the near field up to a distance of meters from the rock surface, even when the surrounding geological formation is saturated and under hydrostatic pressures. A tunnel segment at the Grimsel test site located in the Aare granite of the Bernese Alps (central Switzerland) has been subjected to a resaturation and, subsequently, to a controlled desaturation, Using thermocouple psychrometers (TP) and time domain reflectometry (TDR), the water potentials psi and water contents theta were measured within the unsaturated granodiorite matrix near the tunnel wall at depths between 0 and 160 cm. During the resaturation the water potentials in the first 30 cm from the rock surface changed within weeks from values of less than -1.5 MPa to near saturation. They returned to the negative initial values during desaturation, The dynamics of this saturation-desaturation regime could be monitored very sensitively using the thermocouple psychrometers, The TDR measurements indicated that water contents changed dose to the surface, but at deeper installation depths the observed changes were within the experimental noise. The field-measured data of the desaturation cycle were used to test the predictive capabilities of the hydraulic parameter functions that were derived from the water retention characteristics psi(theta) determined in the laboratory. A depth-invariant saturated hydraulic conductivity k(s) = 3.0 x 10(-11) m s(-1) was estimated from the psi(t) data at all measurement depths, using the one-dimensional, unsaturated water flow and transport model HYDRUS Vogel er al., 1996, For individual measurement depths, the estimated k(s) varied between 9.8 x 10(-12) and 6.1 x 10(-11) The fitted k(s) values fell within the range of previously estimated k(s) for this location and led to a satisfactory description of the data, even though the model did not include transport of water vapor.
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BACKGROUND: Impaired manual dexterity is frequent and disabling in patients with multiple sclerosis (MS). Therefore, convenient, quick and validated tests for manual dexterity in MS patients are needed. OBJECTIVE: The aim of this study was to validate the Coin Rotation task (CRT) to examine manual dexterity in patients with MS. DESIGN: Cross-sectional study. METHODS: 101 outpatients with MS were assessed with the CRT, the Expanded Disability Status Scale (EDSS), the Scale for the assessment and rating of ataxia (SARA), the Modified Ashworth Scale (MAS), and their muscle strength and sensory deficits of the hands were noted. Concurrent validity and diagnostic accuracy of the CRT were determined by comparison with the Nine Hole Peg Test (9HPT). Construct validity was determined by comparison with a valid dexterity questionnaire. Multiple regression analysis was done to explore correlations of the CRT with the EDSS, SARA, MAS, muscle strength and sensory deficits. RESULTS: The CRT correlated significantly with the 9HPT (r=.73, p<.0001) indicating good concurrent validity. The cut-off values for the CRT relative to the 9HPT were 18.75 seconds for the dominant (sensitivity: 81.5%; specificity 80.0%) and 19.25 seconds for the non-dominant hand (sensitivity: 90.3%; specificity: 81.8%) demonstrating good diagnostic accuracy. Furthermore, the CRT correlated significantly with the dexterity questionnaire (r=-.49, p<.0001) indicating moderate construct validity. Multiple regression analyses revealed that the EDSS was the strongest predictor for impaired dexterity. LIMITATIONS: Mostly relapsing-remitting MS patients with an EDSS up to 7 were examined. CONCLUSIONS: This study validates the CRT as a test that can be used easily and quickly to evaluate manual dexterity in patients with MS.
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Many techniques based on data which are drawn by Ranked Set Sampling (RSS) scheme assume that the ranking of observations is perfect. Therefore it is essential to develop some methods for testing this assumption. In this article, we propose a parametric location-scale free test for assessing the assumption of perfect ranking. The results of a simulation study in two special cases of normal and exponential distributions indicate that the proposed test performs well in comparison with its leading competitors.
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Need for cognition (NFC) reflects a relatively stable trait regarding the degree to which one enjoys and engages in cognitive endeavors. We examined whether the previously demonstrated one-dimensional structure of the German NFC Scale could be replicated in three samples of undergraduates and secondary school students. Moreover, we investigated the test-retest reliability of the German NFC Scale, which has not yet been tested. Further, we investigated whether the scale would be valid in a sample of secondary school students. Multigroup confirmatory factor analyses established the one-dimensional factor structure of the long form as well as the short form of the German NFC Scale for undergraduates (N = 559), students of academic track secondary schools (German Gymnasium; N = 555), and students of vocational track secondary schools (German Realschule; N = 486). The scale proved to have a high test-retest reliability in a university student sample (N = 43). For secondary school students, we again found a high test-retest reliability (N = 157), and also found the scale to be valid (N = 181).
Resumo:
The "Ardouin Scale of Behavior in Parkinson's Disease" is a new instrument specifically designed for assessing mood and behavior with a view to quantifying changes related to Parkinson's disease, to dopaminergic medication, and to non-motor fluctuations. This study was aimed at analyzing the psychometric attributes of this scale in patients with Parkinson's disease without dementia. In addition to this scale, the following measures were applied: the Unified Parkinson's Disease Rating Scale, the Montgomery and Asberg Depression Rating Scale, the Lille Apathy Rating Scale, the Bech and Rafaelsen Mania Scale, the Positive and Negative Syndrome Scale, the MacElroy Criteria, the Patrick Carnes criteria, the Hospital Anxiety and Depression Scale, and the Mini-International Neuropsychiatric Interview. Patients (n = 260) were recruited at 13 centers across four countries (France, Spain, United Kingdom, and United States). Cronbach's alpha coefficient for domains ranged from 0.69 to 0.78. Regarding test-retest reliability, the kappa coefficient for items was higher than 0.4. For inter-rater reliability, the kappa values were 0.29 to 0.81. Furthermore, most of the items from the Ardouin Scale of Behavior in Parkinson's Disease correlated with the corresponding items of the other scales, depressed mood with the Montgomery and Asberg Depression Rating Scale (ρ = 0.82); anxiety with the Hospital Anxiety and Depression Scale-anxiety (ρ = 0.56); apathy with the Lille Apathy Rating Scale (ρ = 0.60). The Ardouin Scale of Behavior in Parkinson's disease is an acceptable, reproducible, valid, and precise assessment for evaluating changes in behavior in patients with Parkinson's disease without dementia. © 2015 International Parkinson and Movement Disorder Society.
Resumo:
The aim of this study was to determine the reliability of the conditioned pain modulation (CPM) paradigm assessed by an objective electrophysiological method, the nociceptive withdrawal reflex (NWR), and psychophysical measures, using hypothetical sample sizes for future studies as analytical goals. Thirty-four healthy volunteers participated in two identical experimental sessions, separated by 1 to 3 weeks. In each session, the cold pressor test (CPT) was used to induce CPM, and the NWR thresholds, electrical pain detection thresholds and pain intensity ratings after suprathreshold electrical stimulation were assessed before and during CPT. CPM was consistently detected by all methods, and the electrophysiological measures did not introduce additional variation to the assessment. In particular, 99% of the trials resulted in higher NWR thresholds during CPT, with an average increase of 3.4 mA (p<0.001). Similarly, 96% of the trials resulted in higher electrical pain detection thresholds during CPT, with an average increase of 2.2 mA (p<0.001). Pain intensity ratings after suprathreshold electrical stimulation were reduced during CPT in 84% of the trials, displaying an average decrease of 1.5 points in a numeric rating scale (p<0.001). Under these experimental conditions, CPM reliability was acceptable for all assessment methods in terms of sample sizes for potential experiments. The presented results are encouraging with regards to the use of the CPM as an assessment tool in experimental and clinical pain. Trial registration: Clinical Trials.gov NCT01636440.
Resumo:
OBJECTIVE How long clinicians should wait before considering an antipsychotic ineffective and changing treatment in schizophrenia is an unresolved clinical question. Guidelines differ substantially in this regard. The authors conducted a diagnostic test meta-analysis using mostly individual patient data to assess whether lack of improvement at week 2 predicts later nonresponse. METHOD The search included EMBASE, MEDLINE, BIOSIS, PsycINFO, Cochrane Library, CINAHL, and reference lists of relevant articles, supplemented by requests to authors of all relevant studies. The main outcome was prediction of nonresponse, defined as <50% reduction in total score on either the Positive and Negative Syndrome Scale (PANSS) or Brief Psychiatric Rating Scale (BPRS) (corresponding to at least much improved) from baseline to endpoint (4-12 weeks), by <20% PANSS or BPRS improvement (corresponding to less than minimally improved) at week 2. Secondary outcomes were absent cross-sectional symptomatic remission and <20% PANSS or BPRS reduction at endpoint. Potential moderator variables were examined by meta-regression. RESULTS In 34 studies (N=9,460) a <20% PANSS or BPRS reduction at week 2 predicted nonresponse at endpoint with a specificity of 86% and a positive predictive value (PPV) of 90%. Using data for observed cases (specificity=86%, PPV=85%) or lack of remission (specificity=77%, PPV=88%) yielded similar results. Conversely, using the definition of <20% reduction at endpoint yielded worse results (specificity=70%, PPV=55%). The test specificity was significantly moderated by a trial duration of <6 weeks, higher baseline illness severity, and shorter illness duration. CONCLUSIONS Patients not even minimally improved by week 2 of antipsychotic treatment are unlikely to respond later and may benefit from a treatment change.