scholarly journals Neutralizing and binding antibody kinetics of COVID-19 patients during hospital and convalescent phases

2021 ◽  
Author(s):  
Xiang-Yang Yao ◽  
Wei Liu ◽  
Zhi-Yong Li ◽  
Hua-Long Xiong ◽  
Ying-Ying Su ◽  
...  
Keyword(s):  
Regression Coefficient ◽  
Control Strategies ◽  
Illness Onset ◽  
Relative Contribution ◽  
Long Time ◽  
Iga Antibody ◽  
Binding Antibody ◽  
Blood Specimens ◽  
Antibody Kinetics ◽  
Kinetics Of

Abstract Background: Knowledge of host immune response after natural SARS-CoV-2 infection is essential for the direction of vaccination and epidemiological control strategies against COVID-19.Methods: Thirty-four COVID-19 patients were enrolled with 244 serial blood specimens (38.1% after hospital discharge) collected to explore the chronological evolution of neutralizing (NAb), total (TAb), IgM, IgG and IgA antibody in parallel.Results: IgG titers reached a peak later (35 days postonset) than those of Nab, Ab, IgM and IgA (25 days postonset). IgM levels declined with an estimated half-life of 35 days postonset, which was more rapid than those of IgA and IgG (73-76 days postonset). All patients remained positive for NAb, IgG and IgA up to 3 months after illness onset. The relative contribution of IgM to NAb was higher than that of IgG (standardized β regression coefficient: 0.53 vs 0.48). However, the relative contribution of IgG to NAb increased and that of IgM further decreased after 6 weeks postonset.Conclusions: This study suggests that SARS-CoV-2 infection induces robust neutralizing and binding antibody responses in patients. Humoral immunity against SARS-CoV-2 acquired by infection may persist for a relatively long time.

scholarly journals Neutralizing and binding antibody kinetics of COVID-19 patients during hospital and convalescent phases

2020 ◽  
Author(s):  
Xiang-Yang Yao ◽  
Wei Liu ◽  
Zhi-Yong Li ◽  
Hua-Long Xiong ◽  
Ying-Ying Su ◽  
...  
Keyword(s):  
Half Life ◽  
Control Strategies ◽  
Disease Onset ◽  
Rapid Decline ◽  
Relative Contribution ◽  
Long Time ◽  
Iga Antibody ◽  
Binding Antibody ◽  
Blood Specimens ◽  
Antibody Kinetics

Knowledge of the host immune response after natural SARS-CoV-2 infection is essential for informing directions of vaccination and epidemiological control strategies against COVID-19. In this study, thirty-four COVID-19 patients were enrolled with 244 serial blood specimens (38.1% after hospital discharge) collected to explore the chronological evolution of neutralizing (NAb), total (TAb), IgM, IgG and IgA antibody in parallel. IgG titers reached a peak later (approximately 35 days postonset) than those of Nab, Ab, IgM and IgA (20~25 days postonset). After peaking, IgM levels declined with an estimated average half-life of 10.36 days, which was more rapid than those of IgA (51.25 days) and IgG (177.39 days). Based on these half-life data, we estimate that the median times for IgM, IgA and IgG to become seronegative are 4.59 (IQR 4.12-5.03), 7.78 (IQR 6.71-9.16) and 42.72 (IQR 33.75-47.96) months post disease onset. The relative contribution of IgM to NAb was higher than that of IgG (standardized β regression coefficient: 0.53 vs 0.48), so the rapid decline in NAb may be attributed to the rapid decay of IgM in acute phase. However, the relative contribution of IgG to NAb increased and that of IgM further decreased after 6 weeks postonset. It's assumed that the decline rate of NAb might slow down to the same level as that of IgG over time. This study suggests that SARS-CoV-2 infection induces robust neutralizing and binding antibody responses in patients and that humoral immunity against SARS-CoV-2 acquired by infection may persist for a relatively long time.

scholarly journals Antibody response among COVID-19 patient with and without re-detectable positive RT-PCR results in convalescent phases

2021 ◽  
Author(s):  
Jing Peng ◽  
Zhi-Yong Liu ◽  
Xiaojuan YU ◽  
Xiao-Yan Chen ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Antibody Response ◽  
Statistical Significance ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Blood Samples ◽  
Illness Onset ◽  
Antibody Titers ◽  
Iga Antibody ◽  
Antibody Kinetics ◽  
Kinetics Of

Abstract Objective: To analyze the dynamic of total, IgA, IgM and IgG antibody of the confirmed COVID-19 patients during convalescent phases to understand the kinetics of antibody response among recovered patients.Methods: From March 4 to April 29, 2020, a total of 143 recovered COVID-19 patients with clear date of illness onset available were enrolled in this study. Nasopharyngeal and anal swabs were collected for SARS-CoV-2 RNA testing. Blood samples were collected for antibodies testing. Results: A total of 275 blood samples up to 96 days after illness onset were collected from 143 recovered patients. High titers of total and IgG antibodies continued to persist for over 3 months, with 100% and 99.3% patients remaining positive for total and IgG antibody. IgM antibody declined rapidly with a median time to seronegative at 67 (95%CI: 59, 75) days after illness onset. Around 25% patients were seronegative for IgA antibody at month 3 after illness onset. No statistical significance difference was founded in the antibody kinetics between patients with and without re-detectable positive RT-PCR results during in convalescent phases. Conclusion: Similar high antibody titers of total and IgG antibody continued to persist for over 3 months among recovered COVID-19 patients with and without re-detectable positive RT-PCR results.

scholarly journals Single entity electrochemistry and the electron transfer kinetics of hydrazine oxidation

Nano Research ◽  
2021 ◽  
Author(s):  
Ruiyang Miao ◽  
Lidong Shao ◽  
Richard G. Compton
Keyword(s):  
Electron Transfer ◽  
Bulk Solution ◽  
Relative Contribution ◽  
Rate Determining Step ◽  
Multistep Process ◽  
Ph Range ◽  
Electro Catalytic Oxidation ◽  
Single Particle Impact ◽  
The Impact ◽  
Kinetics Of

AbstractThe mechanism and kinetics of the electro-catalytic oxidation of hydrazine by graphene oxide platelets randomly decorated with palladium nanoparticles are deduced using single particle impact electrochemical measurements in buffered aqueous solutions across the pH range 2–11. Both hydrazine, N2H4, and protonated hydrazine N2H5+ are shown to be electroactive following Butler-Volmer kinetics, of which the relative contribution is strongly pH-dependent. The negligible interconversion between N2H4 and N2H5+ due to the sufficiently short timescale of the impact voltammetry, allows the analysis of the two electron transfer rates from impact signals thus reflecting the composition of the bulk solution at the pH in question. In this way the rate determining step in the oxidation of each specie is deduced to be a one electron step in which no protons are released and so likely corresponds to the initial formation of a very short-lived radical cation either in solution or adsorbed on the platelet. Overall the work establishes a generic method for the elucidation of the rate determining electron transfer in a multistep process free from any complexity imposed by preceding or following chemical reactions which occur on the timescale of conventional voltammetry.

scholarly journals Multifaceted phase ordering kinetics of an antiferromagnetic spin-1 condensate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joanna Pietraszewicz ◽  
Aleksandra Seweryn ◽  
Emilia Witkowska
Keyword(s):  
Scaling Laws ◽  
Study Phase ◽  
One Dimensional ◽  
Phase Domain ◽  
Ordering Kinetics ◽  
Domain Coarsening ◽  
Long Time ◽  
Phase Ordering ◽  
Kinetics Of ◽  
Antiferromagnetic Spin

AbstractWe study phase domain coarsening in the long time limit after a quench of magnetic field in a quasi one-dimensional spin-1 antiferromagnetic condensate. We observe that the growth of correlation length obeys scaling laws predicted by the two different models of phase ordering kinetics, namely the binary mixture and vector field. We derive regimes of clear realization for both of them. We demonstrate appearance of atypical scaling laws, which emerge in intermediate regions.

Luminescence kinetics of semiconductor doped glasses in the long time region

1992 ◽  
Vol 71 (2) ◽  
pp. 942-945 ◽  
Author(s):  
S. Burkitbaev ◽  
M. Bertolotti ◽  
E. Fazio ◽  
A. Ferrari ◽  
G. Liakhou ◽  
...  
Keyword(s):  
Luminescence Kinetics ◽  
Long Time ◽  
Doped Glasses ◽  
Time Region ◽  
Kinetics Of

Kinetics of antigen-specific IgM/IgG/IgA antibody responses during Zika virus natural infection in two patients

2018 ◽  
Vol 91 (5) ◽  
pp. 872-876 ◽  
Author(s):  
Ling-Zhai Zhao ◽  
Wen-Xin Hong ◽  
Jian Wang ◽  
Lei Yu ◽  
Feng-Yu Hu ◽  
...  
Keyword(s):  
Zika Virus ◽  
Natural Infection ◽  
Antibody Responses ◽  
Iga Antibody ◽  
Kinetics Of

scholarly journals Increasing autophagy does not affect neurogenic muscle atrophy

2018 ◽  
Vol 28 (3) ◽  
Author(s):  
Eva Pigna ◽  
Krizia Sanna ◽  
Dario Coletti ◽  
Zhenlin Li ◽  
Ara Parlakian ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Muscle Atrophy ◽  
Ubiquitin Proteasome System ◽  
Autophagic Flux ◽  
Molecular Pathways ◽  
Muscle Loss ◽  
Relative Contribution ◽  
Ubiquitin Proteasome ◽  
Muscle Mass Loss ◽  
Kinetics Of

Physiological autophagy plays a crucial role in the regulation of muscle mass and metabolism, while the excessive induction or the inhibition of the autophagic flux contributes to the progression of several diseases. Autophagy can be activated by different stimuli, including cancer, exercise, caloric restriction and denervation. The latter leads to muscle atrophy through the activation of catabolic pathways, i.e. the ubiquitin-proteasome system and autophagy. However, the kinetics of autophagy activation and the upstream molecular pathways in denervated skeletal muscle have not been reported yet. In this study, we characterized the kinetics of autophagic induction, quickly triggered by denervation, and report the Akt/mTOR axis activation. Besides, with the aim to assess the relative contribution of autophagy in neurogenic muscle atrophy, we triggered autophagy with different stimuli along with denervation, and observed that four week-long autophagic induction, by either intermitted fasting or rapamycin treatment, did not significantly affect muscle mass loss. We conclude that: i) autophagy does not play a major role in inducing muscle loss following denervation; ii) nonetheless, autophagy may have a regulatory role in denervation induced muscle atrophy, since it is significantly upregulated as early as eight hours after denervation; iii) Akt/mTOR axis, AMPK and FoxO3a are activated consistently with the progression of muscle atrophy, further highlighting the complexity of the signaling response to the atrophying stimulus deriving from denervation.

scholarly journals Kinetics of the cercaria-schistosomul um transformation in vivo: 2. The effect of oxamniquine

1985 ◽  
Vol 18 (4) ◽  
pp. 251-255 ◽  
Author(s):  
A. L. Melo ◽  
L.H. Pereira
Keyword(s):  
Peritoneal Cavity ◽  
Abdominal Cavity ◽  
Long Time ◽  
Peritoneal Washings ◽  
High Doses ◽  
Kinetics Of

To study the cercaria-schistosomulum transformation in vivo, underthe influence of an antischistosomal compound (oxamniquine), a model using cercarial infections into the abdominal cavity of mice was chosen. This procedure provided easy and reproducible recoveries of larvae from peritoneal washings with appropriate solutions for a long time (30 to 180 min) after inoculation. The results show that high doses of oxamniquine (given intramuscularly one hour before the infection) produce a marked delay in the kinetics of the cercaria-schistosomulum transformation. Cercariae, tail-less cercarial bodies and schistosomula were recovered from the peritoneal cavity ofdrug treated mice in numbers significantly different from those recovered from untreated mice.

scholarly journals Safety and Antibody Kinetics of COVID-19 Convalescent Plasma for the Treatment of Moderate to Severe Cases of SARS-CoV-2 Infection in Pediatric Patients

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Antonio Arrieta ◽  
Alvaro E. Galvis ◽  
Tricia Morphew ◽  
Louis Ehwerhemuepha ◽  
Stephanie Osborne ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Antibody Kinetics ◽  
Kinetics Of

scholarly journals The effect of loading frequency on the cyclic mechanical behavior of polyethylene

2015 ◽  
Vol 18 (4) ◽  
pp. 162-169
Author(s):  
Thao Song Thanh Nguyen ◽  
Nhung Thi Tuyet Le
Keyword(s):  
Experimental Investigation ◽  
Mechanical Behavior ◽  
Hysteresis Loop ◽  
Room Temperature ◽  
Tensile Tests ◽  
Loading Frequency ◽  
Ratcheting Strain ◽  
Accumulated Strain ◽  
Long Time ◽  
Kinetics Of

An experimental investigation into ratcheting strain and stress-strain hysteresis loop in stress-controlled cyclic tensile tests at room temperature was performed to determine the effect of loading frequency on the cyclic mechanical behavior of highdensity polyethylene (HDPE). It was found that frequencies ranging from 0.01 Hz up to 1 Hz mostly affects the accumulated strain over related time scales (i.e that of the cycle itself) and not over long time scale (i.e. during the full test). In addition, the higher the frequency is, the more closed and vertical the loops are. Furthermore, the frequency affects only on the kinetics of stabilization of ratcheting strain but not on one of hysteresis loop.

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