scholarly journals Age matters

2019 ◽  
Vol 6 (4) ◽  
pp. e576 ◽  
Author(s):  
Pierre R. Bourque ◽  
John Brooks ◽  
Christopher R. McCudden ◽  
Jodi Warman-Chardon ◽  
Ari Breiner
Keyword(s):  
Lumbar Puncture ◽  
High Sensitivity ◽  
Lower Sensitivity ◽  
Main Role ◽  
Fisher Syndrome ◽  
Ottawa Hospital ◽  
Diagnostic Certainty ◽  
Upper Limits ◽  
Acute Neuropathy ◽  
Reference Limits

ObjectiveWe conducted a retrospective review of patients with a diagnosis of Guillain-Barré syndrome (GBS) to assess the diagnostic impact of applying age-adjusted upper limits for CSF total protein (CSF-TP) supported by a systematic literature review.MethodsCases coded as GBS or inflammatory neuropathy for the period 2001–2016 at The Ottawa Hospital were reviewed. Cases were included if they met the Brighton criteria for GBS with a diagnostic certainty level 1 or 2 and had contemporaneous CSF-TP data. We excluded cases with CSF pleocytosis >50 and cases with Miller-Fisher syndrome. Age-adjusted reference limits were compared with conventional 0.45 and 0.6 g/L upper limits.ResultsOne hundred thirty-eight cases met the study criteria, with a mean age of 47 years. The mean interval from symptom onset to lumbar puncture was 7.9 days, and mean CSF-TP was 1.23 g/L. There was a strong correlation between rising CSF-TP and time to lumbar puncture. Age-adjusted CSF-TP had a significantly lower sensitivity of only 45% in the first week (32% in the first 3 days) compared with 70% in the first week for the 0.45 g/L limit. All upper limits gained high sensitivity after the first week.ConclusionsThe low sensitivity of CSF-TP for the diagnosis of GBS is exacerbated by age-adjusted upper limits. The main role of lumbar puncture in GBS in the first week may be to help exclude other inflammatory or neoplastic etiologies of acute neuropathy. After the first week, the magnitude of the CSF-TP rise reduces the effect of different upper reference limits.

scholarly journals Average fractional polarization of extragalactic sources at Planck frequencies

2018 ◽  
Vol 618 ◽  
pp. A29 ◽  
Author(s):  
T. Trombetti ◽  
C. Burigana ◽  
G. De Zotti ◽  
V. Galluzzi ◽  
M. Massardi
Keyword(s):  
High Sensitivity ◽  
Point Sources ◽  
Distribution Analysis ◽  
Microwave Background ◽  
Residual Noise ◽  
Upper Limits ◽  
Dusty Galaxies ◽  
Using Data ◽  
Polarization Fraction

Recent detailed simulations have shown that an insufficiently accurate characterization of the contamination of unresolved polarized extragalactic sources can seriously bias measurements of the primordial cosmic microwave background (CMB) power spectrum if the tensor-to-scalar ratio r ∼ 0.001, as predicted by models currently of special interest (e.g., Starobinsky’s R2 and Higgs inflation). This has motivated a reanalysis of the median polarization fraction of extragalactic sources (radio-loud AGNs and dusty galaxies) using data from the Planck polarization maps. Our approach, exploiting the intensity distribution analysis, mitigates or overcomes the most delicate aspects of earlier analyses based on stacking techniques. By means of simulations, we have shown that the residual noise bias on the median polarization fraction, Πmedian, of extragalactic sources is generally ≲0.1%. For radio sources, we have found Πmedian ≃ 2.83%, with no significant dependence on either frequency or flux density, in good agreement with the earlier estimate and with high-sensitivity measurements in the frequency range 5–40 GHz. No polarization signal is detected in the case of dusty galaxies, implying 90% confidence upper limits of Πdusty ≲ 2.2% at 353 GHz and of ≲3.9% at 217 GHz. The contamination of CMB polarization maps by unresolved point sources is discussed.

scholarly journals 60–700 K CTAT and PTAT Temperature Sensors with 4H-SiC Schottky Diodes

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 942
Author(s):  
Razvan Pascu ◽  
Gheorghe Pristavu ◽  
Gheorghe Brezeanu ◽  
Florin Draghici ◽  
Philippe Godignon ◽  
...  
Keyword(s):  
Low Cost ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
High Sensitivity ◽  
Xrd Analysis ◽  
Absolute Temperature ◽  
Lower Sensitivity ◽  
Readout Circuit ◽  
Sensing Element ◽  
High Performing

A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported. The structure’s layout places the two identical diodes in close, symmetrical proximity. A stable and high-barrier Schottky contact based on Ni, annealed at 750 °C, is used. XRD analysis evinced the even distribution of Ni2Si over the entire Schottky contact area. Forward measurements in the 60–700 K range indicate nearly identical characteristics for the dual-diodes, with only minor inhomogeneity. Our parallel diode (p-diode) model is used to parameterize experimental curves and evaluate sensing performances over this far-reaching domain. High sensitivity, upwards of 2.32 mV/K, is obtained, with satisfactory linearity (R2 reaching 99.80%) for the CTAT sensor, even down to 60 K. The PTAT differential version boasts increased linearity, up to 99.95%. The lower sensitivity is, in this case, compensated by using a high-performing, low-cost readout circuit, leading to a peak 14.91 mV/K, without influencing linearity.

Fabrication of Piezoelectric Polyvinylidene Fluoride (PVDF) Polymer-Based Tactile Sensor Using Electrospinning Method

2016 ◽  
Vol 12 ◽  
pp. 42-50 ◽  
Author(s):  
N. Manikandan ◽  
S. Muruganand ◽  
K. Sriram ◽  
P. Balakrishnan ◽  
A. Suresh Kumar
Keyword(s):  
Polyvinylidene Fluoride ◽  
Biomedical Application ◽  
Electric Pulse ◽  
High Sensitivity ◽  
Tactile Sensor ◽  
Main Role ◽  
Nano Structure ◽  
Sem Image ◽  
Β Phase ◽  
Α Phase

The polyvinylidene fluoride (PVDF) nanofiber has widely investigated as a sensor and transducer material, because of its high piezo and Ferro electric properties. The novel nano structure of PVDF has attracted considerable interest in the bio sensing and biomedical application. This paper deals with PVDF Tactile sensor. Basically The PVDF acts as piezoelectric effect which convert load into electrical signals. The tactile sensor has a main role for visual handicap and robotics. Any physical activities of robotic in all industrial the tactile sensor is a crucible role, whether it can left the object or handling glass parts pressure of object is main. The Sandwich type PVDF base tactile sensor has been fabricated using nanofiber. Using electro spinning method, the PVDF based nanofiber coated over coper the electrodes. In normal, the PVDF has α-phase and while applying electric pulse the PVDF polymer would be changed from α-phase into β-phase. Only in β-phase, the PVDF act as piezo electrics sensor and measure the piezoelectricity simultaneously measure pressure and temperature in real time. The pressure was monitored from the change in the electrical resistance via the piezo resistance of the material. The enhancement of PVDF properties has been carried by using SEM. The SEM image result showed that the size of nanofiber, the size of nanofiber is varied in the range of (180 nm-400 nm) with smooth surface. The X-Ray diffraction has shown that the PVDF was aggregated with the β-phase crystalline nature. Due to β-phase it was act as a piezo electric prosperity’s and its results are very high sensitivity.

TOWARDS SENSING SINGLE OR A FEW BIO-MOLECULAR ARCHITECTURES: DESIGN OF FUNCTIONAL SURFACES

2008 ◽  
Vol 18 (01) ◽  
pp. 187-194
Author(s):  
PEIJI ZHAO ◽  
DWIGHT WOOLARD ◽  
JORGE M. SEMINARIO ◽  
ROBERT TREW
Keyword(s):  
Density Functional ◽  
High Sensitivity ◽  
Lower Sensitivity ◽  
Label Free ◽  
Dna Molecules ◽  
Surface Attachment ◽  
Biomolecular Sensing ◽  
Aromatic Molecules ◽  
Electrical Sensing ◽  
Silicon Based

There is considerable interest in electrical sensing of biomolecular binding since it has the potential to be label free, to work easily in aqueous environments native to the biomolecules, and to be integrated with small, fast, and inexpensive microelectronoics as detection instrumentation. Although electrochemical methods have been used successfully in detections of DNA molecules with Ag labels at very high sensitivity (~ p ml), detection of DNA molecules in terms of label free techniques has a lower sensitivity (~ μ ml). Here, the surface attachment chemistry is critical towards the detection of ultra-low concentration of biomolecules. In this article, based on density functional theory, we have calculated and analyzed the electrical characteristics of the contact between aromatic molecules and silicon (100) − 2×1 surfaces. Design principles for silicon based electrodes of electrochemically biomolecular sensing instruments for label-free sensing of single or a few biomolecular molecules have also been discussed.

scholarly journals Yebes 40 m radio telescope and the broad band Nanocosmos receivers at 7 mm and 3 mm for line surveys

2021 ◽  
Vol 645 ◽  
pp. A37
Author(s):  
F. Tercero ◽  
J. A. López-Pérez ◽  
J. D. Gallego ◽  
F. Beltrán ◽  
O. García ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Signal To Noise Ratio ◽  
Broad Band ◽  
High Sensitivity ◽  
Lower Sensitivity ◽  
Molecular Chemistry ◽  
Long Baseline ◽  
New Instrumentation ◽  
Frequency Coverage ◽  
Technical Specifications

Context. Yebes 40 m radio telescope is the main and largest observing instrument at Yebes Observatory and is devoted to very long baseline interferometry (VLBI) and single-dish observations since 2010. It has been covering frequency bands between 2 GHz and 90 GHz in discontinuous and narrow windows in most cases in order to match the current needs of the European VLBI Network (EVN) and the Global Millimeter VLBI Array (GMVA). Aims. The Nanocosmos project, a European Union-funded synergy grant, has enabled an increase in the instantaneous frequency coverage of the Yebes 40 m radio telescope, making it possible to observe many molecular transitions with single tunings in single-dish mode. This reduces the observing time and maximises the output from the telescope. Methods. We present technical specifications of the recently installed 31.5−50 GHz (Q band) and 72−90.5 GHz (W band) receivers along with the main characteristics of the telescope at these frequency ranges. We observed IRC+10216, CRL 2688, and CRL 618, which harbour a rich molecular chemistry, to demonstrate the capabilities of the new instrumentation for spectral observations in single-dish mode. Results. Our results show the high sensitivity of the telescope in the Q band. The spectrum of IRC+10126 offers an unprecedented signal-to-noise ratio for this source in this band. On the other hand, the spectrum normalised by the continuum flux towards CRL 618 in the W band demonstrates that the 40 m radio telescope produces comparable results to those from the IRAM 30 m radio telescope, although with a lower sensitivity. The new receivers fulfil one of the main goals of Nanocosmos and open up the possibility to study the spectrum of different astrophysical media with unprecedented sensitivity.

scholarly journals Monitoring "mini-intensity" anticoagulation with warfarin: comparison of the prothrombin time using a sensitive thromboplastin with prothrombin fragment F1+2 levels

Blood ◽  
1992 ◽  
Vol 79 (8) ◽  
pp. 2034-2038 ◽  
Author(s):  
MM Millenson ◽  
KA Bauer ◽  
JP Kistler ◽  
S Barzegar ◽  
L Tulin ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
Factor Xa ◽  
High Sensitivity ◽  
International Normalized Ratio ◽  
Target Range ◽  
Lower Sensitivity ◽  
Sensitivity Index ◽  
Plasma Samples ◽  
Prothrombin Activation

Treatment with warfarin using a target International Normalized Ratio (INR) range of 1.7 to 2.5 is efficacious for many clinical indications, but the minimal intensity of anticoagulation required for antithrombotic protection has yet to be determined. To evaluate whether patients could be reliably monitored with a less intense regimen, we anticoagulated patients with warfarin for several months using a target INR range of 1.3 to 1.6 as determined by prothrombin time (PT) using a sensitive thromboplastin (Dade IS, International Sensitivity Index [ISI] = 1.3). Plasma measurements of F1+2, a marker of factor Xa action on prothrombin in vivo, were also obtained to determine the suppressive effect of warfarin on hemostatic system activity. Overall, 20 of 21 patients with a history of cerebrovascular events (mean age, 61 years) could be reliably regulated with warfarin in the target INR range. F1+2 levels were significantly suppressed from baseline in all patients, with a mean reduction of 49% (range, 28% to 78%). We found a significant relationship between the extent of suppression of prothrombin activation levels and the baseline measurements. A mean reduction of 65% was observed for those patients with baseline F1+2 greater than or equal to 1.5 nmol/L, but only 38% for baseline F1+2 less than or equal to 0.5 nmol/L. Overall, 68% of plasma samples obtained during stable anticoagulation were within the target INR range. PTs were also determined on all plasma samples with two thromboplastins of lower sensitivity (C+, ISI = 2.09; and automated simplastin, ISI = 2.10). Only 47% and 35% of PT determinations, respectively, were within the target range with these reagents. We conclude that prothrombin activation can be significantly suppressed in vivo with use of warfarin in an INR range of 1.3 to 1.6. This level of anticoagulation can be reliably achieved by monitoring PTs with a thromboplastin of high sensitivity.

Abstract 15928: Relative Sparing of Apical Longitudinal Strain for Detection of Cardiac Amyloidosis: Intervendor Variation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Julia M Simkowski ◽  
Michael Jiang ◽  
NADIA El HANGOUCHE ◽  
Jeesoo Lee ◽  
Milica Marion ◽  
...  
Keyword(s):  
Cardiac Amyloidosis ◽  
Longitudinal Strain ◽  
Global Longitudinal Strain ◽  
High Sensitivity ◽  
High Specificity ◽  
Left Ventricular ◽  
Control Group ◽  
Lower Sensitivity ◽  
Medical Systems ◽  
Roc Curve Analysis

Introduction: Relative apical longitudinal strain (RALS) is defined as (average apical LS/(average basal & mid-ventricular LS)). A threshold of 2 has been found to have high sensitivity and specificity for differentiating cardiac amyloidosis (CA) from other causes of left ventricular hypertrophy (LVH). This threshold was developed using General Electric (GE) software, and its reproducibility among different software vendors is unknown. Hypothesis: In patients with CA, regional segmental LS patterns and relative apical longitudinal strain will vary among software vendors. Methods: Speckle-tracking echocardiography was retroactively performed by an experienced technician on two patient cohorts, CA (n=52) and LVH (n=52), using software from two independent vendors: EchoPAC (GE Medical Systems) and TomTEC (TOMTEC Imaging Systems GMBH). For each vendor and patient, strain values for the basal, mid, and apical segments were averaged to obtain three regional LS values which were then used to calculate global longitudinal strain (GLS) and RALS. Results: EchoPAC demonstrated greater average apical LS (-16.5±5.7 vs -13.1±6.6, p<0.001) and RALS (2.1±0.9 vs 1.7±0.7, p<0.001) compared to TomTEC. Bland-Altman analysis yielded a mean bias of -0.4 with limit of agreement 2.2 (p<0.001) in RALS between the two vendors. ROC curve analysis using a RALS cutoff of 2 to differentiate CA from the overall control group showed similarly high specificity (EchoPAC 85%, TomTEC 83%) between vendors but lower sensitivity for TomTEC (23% vs 45%) (Figure 1). LVH subgroup analysis showed similar comparisons. Overall difference in area-under-curve (AUC) was significant (AUC = 0.78 EchoPAC vs AUC = 0.52 TomTEC, p < 0.001). Conclusions: Software measurements of regional LS and thus RALS vary between vendors. Further efforts are needed for intervendor regional strain fidelity. For now, different RALS thresholds to diagnose CA may be needed for various vendors.

scholarly journals Lactate Stress Testing in 155 Patients with Mitochondriopathy

2002 ◽  
Vol 29 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Josef Finsterer ◽  
Erika Milvay
Keyword(s):  
Sensitivity And Specificity ◽  
Oxidative Metabolism ◽  
Neurological Disorders ◽  
Stress Testing ◽  
Diagnostic Yield ◽  
Stress Test ◽  
High Sensitivity ◽  
Serum Lactate ◽  
Reference Limits ◽  
Few Data

Objective:Few data are available about the diagnostic yield of the lactate stress test (LST) in a large group of patients with mitochondriopathy (MCP).Methods:Serum lactate was determined once before, three times during, and once after a 15-minute, constant 30W workload on a bicycle in 62 controls, aged 17 to 84 years, 155 patients with MCP, aged 17 to 87 years, and 31 patients with neurological disorders other than MCP.Results:Lactate's upper reference limits at rest, 5, 10, 15 minutes after starting, and 15 minutes after finishing the exercise were 2.0, 2.1, 2.1, 2.1 and 1.8 mmol/l respectively. The test was regarded abnormal if more than two of the five lactate values exceeded the cut-off levels. Among the 103 patients with abnormal LST, 64 (62 %) had normal resting lactate. The sensitivity of the test was 67% and the specificity 94%.Conclusion:The LST proved to have a high sensitivity and specificity in the detection of patients with MCP, being thus a simple but powerful tool to assess the impaired oxidative metabolism in MCP patients.

scholarly journals Monitoring "mini-intensity" anticoagulation with warfarin: comparison of the prothrombin time using a sensitive thromboplastin with prothrombin fragment F1+2 levels

Blood ◽  
1992 ◽  
Vol 79 (8) ◽  
pp. 2034-2038 ◽  
Author(s):  
MM Millenson ◽  
KA Bauer ◽  
JP Kistler ◽  
S Barzegar ◽  
L Tulin ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
Factor Xa ◽  
High Sensitivity ◽  
International Normalized Ratio ◽  
Target Range ◽  
Lower Sensitivity ◽  
Sensitivity Index ◽  
Plasma Samples ◽  
Prothrombin Activation

Abstract Treatment with warfarin using a target International Normalized Ratio (INR) range of 1.7 to 2.5 is efficacious for many clinical indications, but the minimal intensity of anticoagulation required for antithrombotic protection has yet to be determined. To evaluate whether patients could be reliably monitored with a less intense regimen, we anticoagulated patients with warfarin for several months using a target INR range of 1.3 to 1.6 as determined by prothrombin time (PT) using a sensitive thromboplastin (Dade IS, International Sensitivity Index [ISI] = 1.3). Plasma measurements of F1+2, a marker of factor Xa action on prothrombin in vivo, were also obtained to determine the suppressive effect of warfarin on hemostatic system activity. Overall, 20 of 21 patients with a history of cerebrovascular events (mean age, 61 years) could be reliably regulated with warfarin in the target INR range. F1+2 levels were significantly suppressed from baseline in all patients, with a mean reduction of 49% (range, 28% to 78%). We found a significant relationship between the extent of suppression of prothrombin activation levels and the baseline measurements. A mean reduction of 65% was observed for those patients with baseline F1+2 greater than or equal to 1.5 nmol/L, but only 38% for baseline F1+2 less than or equal to 0.5 nmol/L. Overall, 68% of plasma samples obtained during stable anticoagulation were within the target INR range. PTs were also determined on all plasma samples with two thromboplastins of lower sensitivity (C+, ISI = 2.09; and automated simplastin, ISI = 2.10). Only 47% and 35% of PT determinations, respectively, were within the target range with these reagents. We conclude that prothrombin activation can be significantly suppressed in vivo with use of warfarin in an INR range of 1.3 to 1.6. This level of anticoagulation can be reliably achieved by monitoring PTs with a thromboplastin of high sensitivity.

scholarly journals Replication and cross-validation of T2D subtypes based on clinical variables: an IMI-RHAPSODY study

2020 ◽  
Author(s):  
Roderick C Slieker ◽  
Louise A Donnelly ◽  
Hugo Fitipaldi ◽  
Gerard A Bouland ◽  
Giuseppe N. Giordano ◽  
...  
Keyword(s):  
Cross Validation ◽  
High Sensitivity ◽  
Cross Sectional Study ◽  
Lower Sensitivity ◽  
Sectional Study ◽  
Cross Sectional ◽  
C Peptide ◽  
Clinical Variables ◽  
Insulin Resistant

ABSTRACTAims/hypothesisFive clusters based on clinical characteristics have been suggested as diabetes subtypes: one autoimmune and four subtypes of type 2 diabetes (T2D). In the current study we replicate and cross-validate these T2D clusters in three large cohorts using readily measured variables in the clinic.MethodsIn this cross-sectional study, 15,940 individuals were clustered based on age, BMI, HbA1c, random or fasting C-peptide and HDL in three independent cohorts. Clusters were cross-validated against the original clusters based on HOMA measures. In addition, between cohorts, clusters were cross-validated by re-assigning people based on each cohort’s cluster centres.ResultsFive distinct T2D clusters were identified and mapped back to the original four ANDIS clusters. Using C-peptide and HDL instead of HOMA-B and HOMA-S three of the clusters mapped with high sensitivity (80.6 – 90.7%) to the previously identified Severe Insulin Deficient (SIDD), Severe insulin resistant (SIRD) and Obese (MOD) clusters. The previously described ANDIS MARD cluster could be mapped to the two milder groups in our study – one characterised by high HDL, and the other having not any extreme characteristic (MDH cluster). When these two milder groups were combined they mapped well to the previously labelled MARD cluster (sensitivity 79.4%). In the cross-validation between cohorts, particularly the SIDD and MDH cluster cross-validated well with sensitivities ranging from 73.3% to 97.1%. SIRD and MD showed a lower sensitivity ranging from 36.1% to 92.3% where individuals shifted from SIRD to MD and vice versa.Conclusions/interpretationClusters based on C-peptide instead of HOMA measures result in clusters that resemble those based on HOMA measures, especially for SIDD, SIRD and MOD. By adding HDL, the MARD cluster based upon HOMA measures resulted in the current clustering in two clusters with one cluster having high HDL levels. Cross-validation between cohorts showed generally a good resemblance between cohorts. Together, our results show that the clustering based on clinical variables readily measured in the clinic (age, HbA1c, HDL, BMI and C-peptide) results in informative clusters that are representative of the original ANDIS clusters and stable across cohorts.

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