2,361 research outputs found
Comparison of three assays for total and free PSA using hybritech and WHO calibrations
Publisher Copyright: © 2021 International Institute of Anticancer Research. All rights reserved.Background/Aim: Lack of interchangeability between prostate-specific antigen (PSA) assays could have a clinical impact. We compared PSA assays from different manufacturers and calibrations. Patients and Methods: A total of 233 men who underwent prostate biopsy (PSA: 2-10 ng/ml; Beckman Coulter Access® Hybritech® as reference) were enrolled. Total (tPSA) and free PSA (fPSA) were also measured using the Roche cobas® and the Abbott Architect® methods. Results: Roche tPSA values were ≈ 1% higher than Beckman, while Abbott values were ~5% lower. Roche had the highest diagnostic sensitivity (92%) compared to Beckman Coulter (87%) and Abbott (85%). Roche fPSA was ≈3% lower and Abbott ≈17% higher than that of Beckman. For the percentage of fPSA, Roche had the highest sensitivity (98%). Conclusion: Roche cobas® and Beckman Coulter Access® Hybritech® tPSA were almost interchangeable. While the agreement was acceptable for tPSA, this did not happen with fPSA and greater efforts for harmonization are required.publishersversionpublishe
The enthalpies of dissociation of the N-O bonds in two quinoxaline derivatives
The present work reports the first experimental thermochemical study of mono-N-oxides derived from quinoxaline, namely, 3-methoxycarbonyl-2-methyl-quinoxaline N-oxide and 3-ethoxycarbonyl-2-methyl-quinoxaline N-oxide. The values of the enthalpies of formation, in the condensed state, and of the enthalpies of sublimation, derived from static bomb calorimetry and Calvet microcalorimetry measurements, respectively, are combined to derive the standard molar enthalpies of formation in the gaseous phase for these two compounds. From the latter values, the first and second N-O bond dissociation enthalpies for the corresponding di-N-oxides have been obtained. The gas-phase experimental results are also compared with calculated data obtained with a density functional theory approach. Copyright (c) 2008 John Wiley & Sons, Ltd
Quality Assessment of Photoplethysmography Signals For Cardiovascular Biomarkers Monitoring Using Wearable Devices
Photoplethysmography (PPG) is a non-invasive technology that measures changes
in blood volume in the microvascular bed of tissue. It is commonly used in
medical devices such as pulse oximeters and wrist worn heart rate monitors to
monitor cardiovascular hemodynamics. PPG allows for the assessment of
parameters (e.g., heart rate, pulse waveform, and peripheral perfusion) that
can indicate conditions such as vasoconstriction or vasodilation, and provides
information about microvascular blood flow, making it a valuable tool for
monitoring cardiovascular health. However, PPG is subject to a number of
sources of variations that can impact its accuracy and reliability, especially
when using a wearable device for continuous monitoring, such as motion
artifacts, skin pigmentation, and vasomotion. In this study, we extracted 27
statistical features from the PPG signal for training machine-learning models
based on gradient boosting (XGBoost and CatBoost) and Random Forest (RF)
algorithms to assess quality of PPG signals that were labeled as good or poor
quality. We used the PPG time series from a publicly available dataset and
evaluated the algorithm s performance using Sensitivity (Se), Positive
Predicted Value (PPV), and F1-score (F1) metrics. Our model achieved Se, PPV,
and F1-score of 94.4, 95.6, and 95.0 for XGBoost, 94.7, 95.9, and 95.3 for
CatBoost, and 93.7, 91.3 and 92.5 for RF, respectively. Our findings are
comparable to state-of-the-art reported in the literature but using a much
simpler model, indicating that ML models are promising for developing remote,
non-invasive, and continuous measurement devices.Comment: 9 page
Predictors of high-quality cord blood units
BACKGROUNDAnalysis of umbilical cord blood (UCB) transplants shows a correlation between engraftment and total number of infused cells. Thus, it is worth evaluating what maternal and neonatal characteristics and collection techniques may affect the quality of UCB units. STUDY DESIGN AND METHODSA cross-sectional study was performed with 7897 donors sequentially selected in three health care institutions in Brazil from October 2004 to March 2012, in which both quantitative and qualitative approaches were applied. All donors were considered suitable for cord blood collection. RESULTSThe maternal and neonatal characteristics and techniques of collection that influenced the total number of nucleated cells (TNCsp<0.001) were type of delivery, newborn weight and sex, and institution of UCB collection. The TNC count was associated with gestational age (p=0.008), type of delivery (p<0.001), newborn sex (p<0.001), newborn weight (p<0.001), and UCB collection technique (p=0.003). Center B presented the largest number of nucleated cells in its results (p<0.001), followed by Center A (p=0.001). Other characteristics, such as maternal age, were analyzed but were not relevant for the nucleated cell number. CONCLUSIONThis study provides elements for a model that allows an efficient selection of UCB donors, prioritizing candidates who have a better chance to lead to an optimized use of cord blood cells units.Univ Fed Sao Paulo UNIFESP, Escola Paulista Enfermagem, Sao Paulo, BrazilInst Nacl Cardiol, Rio De Janeiro, BrazilInst Israelita Ensino & Pesquisa Albert Einstein, Sao Paulo, BrazilHosp Israelita Albert Einstein, Dept Hemoterapia, Sao Paulo, BrazilUniv Fed Sao Paulo UNIFESP, Escola Paulista Enfermagem, Sao Paulo, BrazilWeb of Scienc
ENERGETIC AND STRUCTURAL EFFECTS ON OXYGEN OR SULFUR HETEROPOLYCYCLIC COMPOUNDS
The present article involves a comparative study of the influence of oxygen or sulfur heteroatoms present in the central ring of polycyclic compounds, in order to clarify the correlation between the respective thermophysical or thermochemical properties and structural characteristics. Considering the importance of these types of compounds for their broad spectrum of application in diverse fields, from pharmacology to the development of new materials, the critical interpretation of such properties for their crucial role in the reactivity of these substances is of great interest. Knowledge on these thermodynamic data for key compounds is also relevant to the prediction and understanding of the properties and behavior of other parent compounds
Strong enhancement of magnetic ordering temperature and structural/valence transitions in EuPd3S4 under high pressure
We present a comprehensive study of the mixed valent compound, EuPd3S4, by
electrical transport, X-ray diffraction, time-domain 151Eu synchrotron
M\"ossbauer spectroscopy, and X-ray absorption spectroscopy measurements under
high pressure. The electrical transport measurements show that the
antiferromagnetic ordering temperature, TN, increases rapidly from 2.8 K at
ambient pressure to 23.5 K at ~19 GPa and plateaus between ~19 and ~29 GPa
after which no anomaly associated with TN is detected. A pressure-induced first
order structural transition from cubic to tetragonal is observed, with a rather
broad coexistence region (~20 GPa to ~32 GPa) that corresponds to the TN
plateau. M\"ossbauer spectroscopy measurements show a clear valence transition
from approximately 50:50 Eu2+:Eu3+ to fully Eu3+ at ~28 GPa, consistent with
the vanishing of the magnetic order at the same pressure. X-ray absorption data
show a transition to a fully trivalent state at a similar pressure. Our results
show that pressure first greatly enhances TN, most likely via enhanced
hybridization between the Eu 4f states and the conduction band, and then,
second, causes a structural phase transition that coincides with the conversion
of the europium to a fully trivalent state.Comment: 28 pages, 6 figures in main manuscript, 10 figures in S
Ixonnexin from Tick Saliva Promotes Fibrinolysis by Interacting with Plasminogen and Tissue-Type Plasminogen Activator, and Prevents Arterial Thrombosis
Tick saliva is a rich source of modulators of vascular biology. We have characterized Ixonnexin, a member of the “Basic-tail” family of salivary proteins from the tick Ixodes scapularis. Ixonnexin is a 104 residues (11.8 KDa), non-enzymatic basic protein which contains 3 disulfide bonds and a C-terminal rich in lysine. It is homologous to SALP14, a tick salivary FXa anticoagulant. Ixonnexin was produced by ligation of synthesized fragments (51–104) and (1–50) followed by folding. Ixonnexin, like SALP14, interacts with FXa. Notably, Ixonnexin also modulates fibrinolysis in vitro by a unique salivary mechanism. Accordingly, it accelerates plasminogen activation by tissue-type plasminogen activator (t-PA) with Km 100 nM; however, it does not affect urokinase-mediated fibrinolysis. Additionally, lysine analogue ε-aminocaproic acid inhibits Ixonnexin-mediated plasmin generation implying that lysine-binding sites of Kringle domain(s) of plasminogen or t-PA are involved in this process. Moreover, surface plasmon resonance experiments shows that Ixonnexin binds t-PA, and plasminogen (KD 10 nM), but not urokinase. These results imply that Ixonnexin promotes fibrinolysis by supporting the interaction of plasminogen with t-PA through formation of an enzymatically productive ternary complex. Finally, in vivo experiments demonstrates that Ixonnexin inhibits FeCl3-induced thrombosis in mice. Ixonnexin emerges as novel modulator of fibrinolysis which may also affect parasite-vector-host interactions
Comparative Analysis of the Global Transcriptome of Anopheles funestus from Mali, West Africa
Background: Anopheles funestus is a principal vector of malaria across much of tropical Africa and is considered one of the most efficient of its kind, yet studies of this species have lagged behind those of its broadly sympatric congener, An. gambiae. In aid of future genomic sequencing of An. funestus, we explored the whole body transcriptome, derived from mixed stage progeny of wild-caught females from Mali, West Africa. Principal Findings: Here we report the functional annotation and comparative genomics of 2,005 expressed sequence tags (ESTs) from An. funestus, which were assembled with a previous EST set from adult female salivary glands from the same mosquito. The assembled ESTs provided for a nonredundant catalog of 1,035 transcripts excluding mitochondrial sequences. Conclusions/Significance: Comparison of the An. funestus and An. gambiae transcriptomes using computational and macroarray approaches revealed a high degree of sequence identity despite an estimated 20–80 MY divergence time between lineages. A phylogenetically broader comparative genomic analysis indicated that the most rapidly evolving proteins – those involved in immunity, hematophagy, formation of extracellular structures, and hypothetical conserved proteins – are those that probably play important roles in how mosquitoes adapt to their nutritional and externa
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Genomics of Loa loa, a Wolbachia-free filarial parasite of humans
Loa loa, the African eyeworm, is a major filarial pathogen of humans. Unlike most filariae, Loa loa does not contain the obligate intracellular Wolbachia endosymbiont. We describe the 91.4 Mb genome of Loa loa, and the genome of the related filarial parasite Wuchereria bancrofti, and predict 14,907 Loa loa genes based on microfilarial RNA sequencing. By comparing these genomes to that of another filarial parasite, Brugia malayi, and to several other nematode genomes, we demonstrate synteny among filariae but not with non-parasitic nematodes. The Loa loa genome encodes many immunologically relevant genes, as well as protein kinases targeted by drugs currently approved for humans. Despite lacking Wolbachia, Loa loa shows no new metabolic synthesis or transport capabilities compared to other filariae. These results suggest that the role played by Wolbachia in filarial biology is more subtle than previously thought and reveal marked differences between parasitic and non-parasitic nematodes
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