59 research outputs found

    Evaluating performance of multivariable vibration isolators : a frequency domain identification approach applied to an industrial AVIS:A frequency domain identification approach applied to an industrial AVIS

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    Vibration isolation is essential for industrial high-precision systems in suppressing the influence of external disturbances. The aim of this paper is to develop an identification method to estimate the transmissibility matrix for such systems. The transmissibility matrix is a key performance indicator in vibration isolation, but its identification is severely limited by the heavy weight and size of many industrial systems. Two non-parametric system identification methods based on periodic and spectral analysis are compared. It is shown that spectral analysis can benefit from random floor excitations at low frequencies and periodic shaker excitations at high frequencies. Using this method, a transmissibility matrix between 1 and 100 Hz is successfully measured on an industrial active vibration isolation system (AVIS), demonstrating that the proposed method is suitable for identification of these heavy-weight systems.</p

    Evaluating performance of multivariable vibration isolators : a frequency domain identification approach applied to an industrial AVIS:A frequency domain identification approach applied to an industrial AVIS

    Get PDF
    Vibration isolation is essential for industrial high-precision systems in suppressing the influence of external disturbances. The aim of this paper is to develop an identification method to estimate the transmissibility matrix for such systems. The transmissibility matrix is a key performance indicator in vibration isolation, but its identification is severely limited by the heavy weight and size of many industrial systems. Two non-parametric system identification methods based on periodic and spectral analysis are compared. It is shown that spectral analysis can benefit from random floor excitations at low frequencies and periodic shaker excitations at high frequencies. Using this method, a transmissibility matrix between 1 and 100 Hz is successfully measured on an industrial active vibration isolation system (AVIS), demonstrating that the proposed method is suitable for identification of these heavy-weight systems.</p

    Techniques of futuring: On how imagined futures become socially performative

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    The concept of the future is re-emerging as an urgent topic on the academic agenda. In this article, we focus on the ā€˜politics of the futureā€™: the social processes and practices that allow particular imagined futures to become socially performative. Acknowledging that the performativity of such imagined futures is well-understood, we argue that how particular visions come about and why they become performative is underexplained. Drawing on constructivist sociological theory, this article aims to fill (part of) this gap by exploring the question ā€˜how do imagined futures become socially performativeā€™? In doing so, the article has three aims to (1) identify the leading socialā€“theoretical work on the future; (2) conceptualize the relationship of the imagination of the future with social practices and the performance of reality; (3) provide a theoretical framework explaining how images of the future become performative, using the concepts ā€˜techniques of futuringā€™ and ā€˜dramaturgical regimeā€™

    Determination of Ki-67 defined growth fraction by monoclonal antibody MIB- I in formalin-fixed, paraffin-embedded prostatic cancer tissues

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    The applicability of MIBā€1, a monoclonal antibody directed against the Kiā€67 antigen, was studied in the PCā€82 and LNCaP prostatic tumor models at various levels of proliferative activity. Statistically significant correlations were found in LNCaP cultures between Kiā€67 and MIBā€1 scores (r = 0.84, P < 0.001), and in PCā€82 tumors between MIBā€1 scores and paraffin tissue Kiā€67 (pKiā€67) (r = 0.90, P < 0.001), frozen tissue Kiā€67 (fKiā€67) (r = 0.86, P < 0.001), and BrdU uptake (r = 0.70, P < 0.001), respectively. pKiā€67 scores were double the fKiā€67 scores, which may be due to methodological differences. MIBā€1 scores exceeded both the fKiā€67 and pKiā€67 scores. The affinity of MIBā€1 for the antigen is much higher than the affinity of Kiā€67, which may explain the differences. MIBā€1 is a promising means of evaluating the presence of only minute amounts of the Kiā€67 antigen in paraffinā€embedded human tumor material, especially in relatively slowly growing tumors

    Influence of beta(2)-adrenoceptor gene polymorphisms on diet-induced thermogenesis

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    The sympathetic nervous system is involved in the control of energy metabolism and expenditure. Diet-induced thermogenesis is mediated partly by the Ɵ-adrenergic component of this system. The aim of the present study was to investigate the role of genetic variation in the Ɵ2-adrenoceptor in diet-induced thermogenesis. Data from twenty-four subjects (fourteen men and ten women; BMI 26Ā·7(SEM 0Ā·8) kg/m2; age 45Ā·2(SEM1Ā·4) years) with different polymorph-isms of the Ɵ2-adrenoceptor at codon 16 (Gly16Gly, Gly16Arg or Arg16Arg) were recruited for this study. Subjects were given a high-carbohydrate liquid meal, and the energy expenditure, respiratory exchange ratio, and plasma concentrations of NEFA, glycerol, glucose, insulin and catecholamines were measured before and over 4 h after the meal. The AUC of energy expenditure (diet-induced thermogenesis) was not significantly different between poly-morphism groups, nor was the response of any of the other measured variables to the meal. In a multiple regression model, the only variable that explained a significant proportion (32 %) of the variation in diet-induced thermogenesis was the increase in plasma adrenaline in response to the meal (P,0Ā·05). The Ɵ2-adrenoceptor codon16 polymorphisms did not contribute significantly. In conclusion, an independent contribution of the codon 16 polymorphism of the Ɵ2-adrenoceptor gene to the variation in thermogenic response to a high-carbohydrate meal could not be demonstrated. The interindividual variation in thermo-genic response to the meal was correlated with variations in the plasma adrenaline response to the meal. Ɵ2-Adrenoceptor polymorphisms: Diet-induced thermogenesis: Catecholamines Energy expenditure (EE) is an important factor in body-weight regulation. Diet-induced thermogenesis (DIT) is the EE associ-ated with ingestion, absorption and storage of food and account

    The predictive value of the modified early warning score for admission to the intensive care unit in patients with a hematologic malignancy ā€“ A multicenter observational study

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    Objectives: The modified early warning score (MEWS) is used to detect clinical deterioration of hospitalized patients. We aimed to investigate the predictive value of MEWS and derived quick Sequential Organ Failure Assessment (qSOFA) scores for intensive care unit admission in patients with a hematologic malignancy admitted to the ward. Design: Retrospective, observational study in two Dutch university hospitals. Setting: Data from adult patients with a hematologic malignancy, admitted to the ward over a 2-year period, were extracted from electronic patient files. Main outcome measures: Intensive care admission. Results: We included 395 patients with 736 hospital admissions; 2% (n = 15) of admissions resulted in admission to the intensive care unit. A higher MEWS (OR 1.5; 95 %CI 1.3ā€“1.80) and qSOFA (OR 4.4; 95 %CI 2.1ā€“9.3) were associated with admission. Using restricted cubic splines, a rise in the probability of admission for a MEWS ā‰„ 6 was observed. The AUC of MEWS for predicting admission was 0.830, the AUC of qSOFA was 0.752. MEWS was indicative for intensive care unit admission two days before admission. Conclusions: MEWS was a sensitive predictor of ICU admission in patients with a hematologic malignancy, superior to qSOFA. Future studies should confirm cut-off values and identify potential additional characteristics, to further enhance identification of critically ill hemato-oncology patients. Implications for Clinical Practice: The Modified Early Warning Score (MEWS) can be used as a tool for healthcare providers to monitor clinical deterioration and predict the need for intensive care unit admission in patients with a hematologic malignancy. Yet, consistent application and potential reevaluation of current thresholds is crucial. This will enable bedside nurses to more effectively identify patients needing adjunctive care, facilitating timely interventions and improved outcome.</p

    Kinetics of neuroendocrine differentiation in an androgen-dependent human prostate xenograft model

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    It was previously shown in the PC-295 xenograft that the number of chromogranin A (CgA)-positive neuroendocrine (NE) cells increased after androgen withdrawal. NE cells did not proliferate and differentiated from G0-phase-arrested cells. Here we further characterized NE differentiation, androgen receptor status, and apoptosis-associated Bcl-2 expression in the PC-295 model after androgen withdrawal to assess the origin of NE cells. PC-295 tumor volumes decreased by 50% in 4 days. Intraperitoneal bromodeoxyuridine (BrdU) incorporation and MIB-1 labeling decreased to 0%, and the apoptosis was maximal at day 4. Androgen receptor expression and prostate-specific antigen (PSA) serum levels decreased rapidly within 2 days. The number of NE cells increased 6-fold at day 4 and 30-fold at day 7. Five and ten percent of the CgA-positive cells were BrdU positive after continuous BrdU labeling for 2 and 4 days, respectively. However, no MIB-1 expression was observed in CgA-positive cells. NE cells expressed the regulated secretory pathway marker secretogranin III but were negative for androgen receptor and Bcl-2. Bcl-2 expression did increase in the non-NE tumor cells. In conclusion, androgen withdrawal leads to a rapid PC-295 tumor regression and a proliferation-independent induction of NE differentiation. The strictly androgen-independent NE cells that were still present after 21 days differentiated mainly from G0-phase-arrested cells

    Expression and prognostic value of Wilms' tumor 1 and early growth response 1 proteins in nephroblastoma

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    Wilms' tumor is one of the most common solid tumors of children. The protein product of the tumor-suppressor gene, Wilms' tumor 1 (WT-1), binds to the same DNA sequences as the protein product of the early growth response 1 (EGR-1) gene. There is experimental evidence that EGR-1 is involved in controlling cell growth. The expression of both genes in Wilms' tumor was studied by others, mainly at the mRNA level. The present study evaluates the prognostic value of WT-1 and EGR-1 in 61 Wilms' tumors of chemotherapeutically treated patients at the protein level, using an immunohistochemical approach. WT-1 was expressed in normal kidney tissues and in the blastemal and epithelial component of Wilms' tumor, whereas stromal tissue was negative. EGR-1 was expressed in normal kidney tissues and in the three main cell types of Wilms' tumor. In 59 and 56% of Wilms' tumor, the blastemal cells stained for WT-1 and EGR-1, respectively. The blastemal expression of WT-1 and EGR-1 and the epithelial expression of WT-1 were statistically significantly correlated with clinical stage. WT-1 immunoreactivity correlated with EGR-1 expression. Univariate analysis showe

    The spectrum of neutralizing and non-neutralizing anti-FVIII antibodies in a nationwide cohort of 788 persons with hemophilia A

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    Objectives:Ā Anti-factor VIII (FVIII) antibodies have been reported to exhibit both neutralizing and non-neutralizing characteristics. This is the first study investigating the full spectrum of FVIII-specific antibodies, including non-neutralizing antibodies, very-low titer inhibitors, and inhibitors, in a large nationwide population of persons with hemophilia A of all severities.Ā Methods:Ā All persons with hemophilia A (mild (FVIII &gt; 5ā€“40 IU/dL)/moderate [FVIII 1ā€“5 IU/dL)/severe (FVIII &lt; 1 IU/dL)] with an available plasma sample who participated in the sixth Hemophilia in the Netherlands study between 2018 and 2019 were included. The presence of anti-FVIII antibodies of the immunoglobulin A, M, and G isotypes and IgG subclasses, along with antibody titer levels, were assessed using direct-binding ELISAs. FVIII specificity was assessed using a competition-based ELISA approach. The inhibitor status was determined using the Nijmegen ultra-sensitive Bethesda assay (NusBA) and the Nijmegen Bethesda assay (NBA).Ā Results:Ā In total, 788 persons with hemophilia A (336 (42.6%) mild, 123 (15.6%) moderate, 329 (41.8%) severe hemophilia) were included. The median age was 45 years (IQR 24ā€“60), and the majority (50.9%) had over 150 exposure days to FVIII concentrates. Within our population, 144 (18.3%) individuals had non-neutralizing FVIII-specific antibodies, 10 (1.3%) had very low-titer inhibitors (NusBA positive; NBA negative), and 13 (1.6%) had inhibitors (both NusBA and NBA positive). IgG1 was the most abundant FVIII-specific antibody subclass, and the highest titer levels were found for IgG4. In individuals without a reported history of inhibitor development, no clear differences were observed in antibody patterns between those who were minimally or highly exposed to FVIII concentrates. IgG4 subclass antibodies were only observed in persons with a reported history of FVIII inhibitor or in those with a currently detected (very low-titer) inhibitor.Ā Conclusion:Ā In this cross-sectional study, we identified non-neutralizing antibodies in a relatively large proportion of persons with hemophilia A. In contrast, in our population, consisting of persons highly exposed to FVIII concentrates, (very low-titer) inhibitors were detected only in a small proportion of persons, reflecting a well-tolerized population. Hence, our findings suggest that only a small subpopulation of non-neutralizing FVIII-specific antibodies is associated with clinically relevant inhibitors.</p

    The spectrum of neutralizing and non-neutralizing anti-FVIII antibodies in a nationwide cohort of 788 persons with hemophilia A

    Get PDF
    Objectives:Ā Anti-factor VIII (FVIII) antibodies have been reported to exhibit both neutralizing and non-neutralizing characteristics. This is the first study investigating the full spectrum of FVIII-specific antibodies, including non-neutralizing antibodies, very-low titer inhibitors, and inhibitors, in a large nationwide population of persons with hemophilia A of all severities.Ā Methods:Ā All persons with hemophilia A (mild (FVIII &gt; 5ā€“40 IU/dL)/moderate [FVIII 1ā€“5 IU/dL)/severe (FVIII &lt; 1 IU/dL)] with an available plasma sample who participated in the sixth Hemophilia in the Netherlands study between 2018 and 2019 were included. The presence of anti-FVIII antibodies of the immunoglobulin A, M, and G isotypes and IgG subclasses, along with antibody titer levels, were assessed using direct-binding ELISAs. FVIII specificity was assessed using a competition-based ELISA approach. The inhibitor status was determined using the Nijmegen ultra-sensitive Bethesda assay (NusBA) and the Nijmegen Bethesda assay (NBA).Ā Results:Ā In total, 788 persons with hemophilia A (336 (42.6%) mild, 123 (15.6%) moderate, 329 (41.8%) severe hemophilia) were included. The median age was 45 years (IQR 24ā€“60), and the majority (50.9%) had over 150 exposure days to FVIII concentrates. Within our population, 144 (18.3%) individuals had non-neutralizing FVIII-specific antibodies, 10 (1.3%) had very low-titer inhibitors (NusBA positive; NBA negative), and 13 (1.6%) had inhibitors (both NusBA and NBA positive). IgG1 was the most abundant FVIII-specific antibody subclass, and the highest titer levels were found for IgG4. In individuals without a reported history of inhibitor development, no clear differences were observed in antibody patterns between those who were minimally or highly exposed to FVIII concentrates. IgG4 subclass antibodies were only observed in persons with a reported history of FVIII inhibitor or in those with a currently detected (very low-titer) inhibitor.Ā Conclusion:Ā In this cross-sectional study, we identified non-neutralizing antibodies in a relatively large proportion of persons with hemophilia A. In contrast, in our population, consisting of persons highly exposed to FVIII concentrates, (very low-titer) inhibitors were detected only in a small proportion of persons, reflecting a well-tolerized population. Hence, our findings suggest that only a small subpopulation of non-neutralizing FVIII-specific antibodies is associated with clinically relevant inhibitors.</p
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