Miracle-dz/UniFAR-FTUs huggingface dataset:
SARS-CoV-2 induces a durable and antigen specific humoral immunity after asymptomatic to mild COVID-19 infection

Current SARS-CoV-2 serological assays generate discrepant results, and the longitudinal characteristics of antibodies targeting various antigens after asymptomatic to mild COVID-19 are yet to be established. This longitudinal cohort study including 1972 healthcare workers, of which 386 participants exhibited antibodies against the SARS-CoV-2 spike antigen at study inclusion, reveal that these antibodies remain detectable in the vast majority of participants, 98%, at least four months post infection, despite having had no or mild symptoms. These antibody levels did not differ from those found in 59 convalescent COVID-19 patients (p=0.7). Virus neutralization capacity was confirmed by microneutralization assay in 93% of study participants at least four months post infection. Contrary to antibodies targeting the spike protein, antibodies against the nucleocapsid protein were only detected in 68% of previously anti-nucleocapsid IgG positive healthcare workers, and these four-month follow-up levels were substantially lower in healthcare workers than in convalescent COVID-19 patients (p=2*10-5). Our findings support a durable and functional humoral response after SARS-CoV-2 infection, even after no or mild symptoms. We further demonstrate differences in antibody kinetics depending on the antigen, arguing against the use of the nucleocapsid protein as target antigen in population-based SARS-CoV-2 serological surveys.
Spatial-temporal relationship between population mobility and COVID-19 outbreaks in South Carolina: A time series forecasting analysis

Importance: Population mobility is closely associated with coronavirus 2019 (COVID-19) transmission, and it could be used as a proximal indicator to predict future outbreaks, which could inform proactive non-pharmaceutical interventions for disease control. South Carolina (SC) is one of the states which reopened early and then suffered from a sharp increase of COVID-19. Objective: To examine the spatial-temporal relationship between population mobility and COVID-19 outbreaks and use population mobility to predict daily new cases at both state- and county- levels in SC. Design, setting, and participants: This longitudinal study used disease surveillance data and Twitter-based population mobility data from March 6 to November 11, 2020 to describe their changes, examine their correlation, and forecast daily COVID-19 new cases in two-week window in SC and its top five counties with the largest number of cumulative confirmed cases. Poisson count time series model was employed to carry out the research goals. Main outcome and measure: The main outcome was daily new case which was calculated by subtracting the cumulative confirmed cases of previous day from the total cases. Population mobility was assessed using the number of users with travel distance larger than 0.5 mile which was calculated based on their geotagged twitters. Results: Population mobility was positively associated with state-level daily COVID-19 incidence and those of the top five counties (i.e., Charleston, Greenville, Horry, Spartanburg, Richland). At the state-level, final model with time window within the last 7-day had the smallest prediction error, and the prediction accuracy was as high as 98.7%, 90.9%, and 81.6% for the next 3-, 7-, 14- days, respectively. Among Charleston, Greenville, Horry, Spartanburg, and Richland counties, the best predictive models were established based on their observations in the last 9-, 14-, 28-, 20-, and 9- days, respectively. The 14-day prediction accuracy ranged from 60.3% to 74.5%. Conclusions and relevance: Population mobility was positively associated with COVID-19 incidences at both state- and county- levels in SC. Using Twitter-based mobility data could provide acceptable prediction for COVID-19 daily new cases. Population mobility measured via social media platform could inform proactive measures and resource relocations to curb disease outbreaks and their negative influences.
Conformation of Cyclics and Linear Chain Polymers in Bulk by SANS

Small-angle neutron scattering (SANS) has been used to investigate the conformation of linear and cyclic poly(dimethylsiloxane)s (PDMS) in chemically identical, undiluted blends. SANS measurements have been carried out on (1) linear hydrogenous (H) mixed with linear deuterated (D) PDMS and (2) cyclic H mixed with cyclic D PDMS. The conformational behavior of the cyclic and linear polymers is studied over a wide range of molar mass and composition. Isotopic blends of linear PDMS are shown to adopt conformations that agree well with theoretical predictions for Gaussian random-coil polymers and confirm previous SANS studies. As expected for chains obeying Gaussian statistics, the mean radii of gyration, Rg, scale with the weight-average molar mass as Rg ∝ Mw0.5. A detailed study of H/D cyclic PDMS mixtures is presented, and we demonstrate that, since Rg ∝ Mw0.4, highly flexible cyclic polymers in the melt adopt an even more compact conformation than that of unperturbed rings. This behavior confirms previous .
Numerical simulation of cyclic variability in reactivity-controlled compression ignition combustion with a focus on the initial temperature at intake valve closing

Cyclic variations in dual-fuel reactivity-controlled compression ignition combustion were investigated using multi-dimensional simulations of a light-duty diesel engine. By comparing results with measured pressure traces from 300 consecutive cycles, it was found that the standard deviation of the 50% burn point in reactivity-controlled compression ignition combustion could be satisfactorily reproduced by monitoring the sensitivity of the 50% burn point to changes in initial in-cylinder temperature at intake valve closing in the simulations. Using this approach, the influences of fuel reactivity, diesel mass fraction, combustion mode, exhaust gas recirculation rate, intake pressure, and injection strategy on combustion stability were investigated. It was found that diesel/methanol reactivity-controlled compression ignition combustion exhibits larger cyclic variations than diesel/gasoline at the same operating conditions due to the lower reactivity of methanol. Compared to gasoline homogeneous charge compression ignition and diesel partially premixed combustion, diesel/gasoline reactivity-controlled compression ignition combustion showed the lowest cyclic variations for a given 50% burn point. When the 50% burn point was kept constant by adjusting the intake temperature, the introduction of exhaust gas recirculation and an increase in intake pressure resulted in decreased cyclic variations. Under the conditions tested in this study, with the employment of retarded injection timing, single injection, and increased injection pressure, the in-cylinder equivalence ratio becomes richer, which is helpful for the reduction in cyclic variations in reactivity-controlled compression ignition combustion. The overall results indicate that the present approach for describing cyclic variability is useful for practical applications.
Layered crystalline barium phosphate organofunctionalized for cation removal

The available hydroxide groups inside the lamellar cavity of barium phosphate (BaP) were reacted with the silyating agents (RO)3Si(CH2)3Lx (L1 = NH2, L2 = NH(CH2)2NH2, and L3 = NH(CH2)2NH(CH2)2NH2), to yield organofunctionalized nanomaterials BaPSiL1, BaPSiL2, and BaPSiL3. The amount of organofunctional groups covalently attached to the inorganic layer was 1.24, 1.46, and 1.23 mmol g-1, respectively. The basic nitrogen center atoms attached to the pendant organic chains adsorb FeCl3, CuCl2, and ZnCl2 from ethanol solutions to give well-established isotherms at 298 ± 1 K. The results obtained in flow experiments showed a retention and recovery of ca. 100% of the metal ion with packed BaPSiLx columns from solution containing a mixture of these cations. The energetic effect caused by iron, copper, and zinc ion interactions was determined through calorimetric titration at the solid−liquid interface and gave a net thermal effect that enabled the calculation of the exothermic enthalpic values and the equilibriu.
LONG-TERM FIELD COMPARISON OF CERAMIC AND POLY(TETRAFLUOROETHENE) POROUS CUP SOIL-WATER SAMPLERS

The validity of porous cup soil water samplers to extract soil solutions is most often evaluated in short-term laboratory studies. Such laboratory studies differ significantly from the situation in the field. Therefore the aim of the present study was to compare ceramic and PTFE porous cup soil water samplers under natural conditions in a long-term field experiment. Soil solutions were sampled from two depths (E, horizon and BC horizon) in an acidified, sandy forest soil in Denmark. Taking the spatial variability of the forest into account, the mean concentrations of base cations, S042-, Cl-, H+, and nonpurgeable organic carbon (NPOC) obtained with the two sampler types are compared. In most cases the concentrations of solutes and NF’OC in the PTFE cups were higher than the concentrations in the ceramic cups. The differences in mean concentrations of K+, Mg2+, Na+, Cl-, S042-, and NO, obtained with the two samplers were generally within the variability of the PTFE samplers whereas the concentrations of Ca2+, H+, and NPOC obtained with the PTFE samplers were significantly higher than those obtained with the ceramic samplers. The difference in NPOC in the E, horizon is concluded to be caused by filtering. The difference in Ca2+ may to some extent be ascribed to dissolution of “glass pellets” in the PTFE sampler matrix, whereas the difference in H+ concentration between the sampler types remains unexplained.
Plasma metanephrines responses to adreno-sympathetic stress

Background: Plasma metanephrines measurement is a highly sensitive method for the diagnosis of catecholamine producing tumors. Pre-analytical factors such as non specific adrenosympathetic stimulations may alter the specificity of the test. Methods: Free catecholamines and metanephrines were determined in plasma after three adrenosympathetic stimulations: postural change from supine to standing position, insulin-induced hypoglycaemia test and a cold pressure test. Results: Sympatho-neuronal stimulation such as orthostatic stimulation and cold exposure mainly stimulated the release of norepinephrine (+61% and +34%, respectively) and in a weaker way of adrenaline (+28% and +16%, respectively). The resulting rise in normetanephrine and metanephrine is much more attenuated after orthostatic change (+30% and +22%, respectively) and cold exposure (+19% without change for metanephrine). Insulin-induced hypoglycaemia elicited a massive release of epinephrine from the adrenal medulla (+1587 %) and to a lesser extent that of norepinephrine from sympathetic neurons (+134%). Plasma normetanephrine and metanephrine peaked 15 minutes later and peaks were more attenuated (+375% and +58%, respectively). Plasma concentrations exceeded the threshold of the paragangliome detection test in 15% of patients for normetanephrine after orthostatic stimulation and 76% of patients for metanephrine after hypoglycemic stress. Conclusion: A moderate sympatho-excitatory stimulation such as exposure to cold has little influence on plasma metanephrines. In contrast, postural changes and metabolic stresses can lead to falsely positive interpretations of the detection test confirming the requirement of blood sampling after at least 30 minutes of rest in supine position.
Evaluated activity and osmotic coefficients for aqueous solutions: iron chloride and the bi‐univalent compounds of nickel and cobalt

A critical evaluation of the mean activity and osmotic coefficients in aqueous solutions of iron chloride, nickel chloride, perchlorate, and nitrate and twenty‐nine bi‐univalent compounds of cobalt at 298.15 K is presented. Osmotic coefficients were calculated from direct vapor pressure measurements, from isopiestic measurements, from freezing point depression measurements, and from vapor pressure osmometry measurements. Given are empirical coefficients for three different correlating equations, obtained by a weighted least squares fit of the experimental data, and tables consisting of the activity coefficients of the compounds, the osmotic coefficients and activity of water, and the excess Gibbs energy of the solution as functions of the molality for each electrolyte system. The literature coverage is through the computerized version of Chemical Abstracts of April 1979.
The thermodynamic equilibrium between cis- and trans-isomers in stilbene and some derivatives

The thermodynamic cis⇌trans equilibrium in stilbene and its derivatives can be established at room temperature only by the use of catalysts such as atomic iodine. The latter has now been used to determine the above equilibrium in a number of cases. The fraction of cis-isomer at equilibrium is ca. 0·002 in stilbene and the para-substituted derivatives investigated, but increases to 0·07 in αβ-difluorostilbene and 2,4,6-trimethylstilbene, and to 0·20 in α-methylstilbene. These values were used to calculate the respective differences in free energy. Catalysed isomerization, in particular if the catalyst is a product of irradiation, may, under certain conditions, occur concurrently with direct or sensitized photoisomerization, and distort the results of the latter reactions. It is therefore important to distinguish between true photoisomerization, involving the excited states of the molecules undergoing isomerization, and photocatalysed isomerization, involving only the ground states of these molecules.
Hydrogenation of Nitrate in Water to Nitrogen over Pd–Cu Supported on Active Carbon

Catalytic removal of nitrate in water by hydrogenation was investigated by using supported Pd–Cu catalysts at 333 K in a flow system. Active carbon (AC) was superior in conversion, selectivity, and insolubility to other supports. Pd and Cu were not dissolved when supported on AC, even at low pH reaction conditions, while they were considerably released from the surface of γ-Al2O3, SiO2, and ZrO2. The contact time dependence of the reactant and products suggested that the hydrogenation of NO3− is a consecutive reaction with NO2− as an intermediate product and that the hydrogenation of NO2− is a key step in determining selectivity to N2 and NH3. The conversion of NO3− was enhanced greatly by the addition of a small amount of Cu to 5 wt% Pd/AC or of Pd to 3 wt% Cu/AC, indicating that the Pd–Cu site was indispensable to activate the nitrate ion. The yield of N2 went through a maximum at 0.6 wt% Cu in the 5 wt% Pd–Cu/AC. A similar dependence of the N2 yield on Cu content for NO2− hydrogenation strongly supports the proposed reaction pathways. The enhancement of N2 selectivity by the addition of small amounts of Cu can be explained by the selective poisoning of the edge or corner sites of the Pd particles by Cu atoms.
The effect of the Thymus vulgaris extracts on the physicochemical characteristics of cedar wood using angle contact measurement

The aim of the study was to investigate the effect of crude extracts of Thymus vulgaris on wood surface physicochemical characteristics. Thus, the Lifshitz-van der Waals (), acid–base (surface tension components ΔGiwi, electron donor () and electron acceptor () parameters of untreated and treated wood were assessed using contact angle measurement. The main results showed that all T. vulgaris extracts are able to change wood surface properties. Indeed, the samples treated with the product obtained by maceration and ultrasound indicated the hydrophilic character (θw = 29.7 ± 0.3°, ΔGiwi = 17. 78 ± 0.48 mJ/m2 and θw = 18.2 ± 0.2°, ΔGiwi = 30.62 ± 0.31 mJ/m2) respectively, and had less contact angle values than that of untreated wood (θw = 86.0 ± 0.2°). In addition, this treatment has made the wood more donor ( = 44.76 ± 0.3 mJ/m2 and = 53.80 ± 0.3 mJ/m2) than the electron acceptor compared to sample control ( = 2.03 ± 0.04 mJ/m2). Finally, the effect of the extract obtained by ultrasound was found to be more important and significant than those recovered by classical extraction.
Laplacian of charge density for binuclear complexes : terminal vs bridging carbonyls

SCF wave functions have been computed for the ground state of Fe 2 (CO) 9 , Fe 2 (CO) 6 (C 2 H 2 ) and Mn 2 (CO) 10 complexes. These wave functions were the starting point for theoretical studies of the topology of the charge density of several carbonyl types. An analysis of the Laplacian of ρ shows that a bridging carbonyl shows a distribution of the electron density similar to that of a keto group, whereas in the terminal coordination the CO fragment retains the axial symmetry. The integration of the electron density suggests a large transfer of charge from the metal atom to each bridging CO. According to the back-bonding model, the electron density in a bridging carbon is more concentrated in the coordination plane. The atomic properties of equatorial and axial carbonyls in Mn 2 (CO) 10 present some differences
The effects of packaging film and storage temperature on the quality of a dry coleslaw mix packaged in a modified atmosphere

Summary The effects of six packaging treatments on the quality of dry coleslaw packaged in modified atmospheres and stored at 4 and 8 � C for 9 days were determined. The coleslaw was packaged within either oriented polypropylene (OPP) or one of four microperforated OPP films, PA-120, PA-160, PA-190, and PA-210. It was also stored within punctured OPP (i.e. in air). Packaging within OPP resulted in an atmosphere with very low O2 (<1%) and extremely high CO2 (25–35%) levels. These storage conditions had detrimental effects on the quality of coleslaw: loss of firmness, falling pH, high cell permeability and exudate, high surface moisture and poor acceptability of aroma. By contrast, the microperforated films generated less atmosphere modification; in some cases this was insufficiently modified to be technically useful. The relatively high O2 levels in these microperforated packs resulted in lower appearance and colour scores, increased surface dryness and higher firmness values. Increasing storage temperature from 4 to 8 � C resulted in a reduction in shelf-life for all film types. While still not optimal, packaging within microperforated films allowed better preservation of quality and reduced cell membrane damage.
Polymeric Nanoparticles Stabilized by Surfactants: Kinetic Studies

A kinetic study was carried out to monitor the time-dependent formation of surfactant-stabilized polymeric nanoparticles prepared by controlled phase separation. The nanoparticles were made of poly(methylmethacrylate) or polystyrene and several ionic and nonionic surfactants. The dispersion was prepared by fast mixing a solution of the polymers in organic solvents with a solution of a surfactant in water. We observed the formation of well-defined nanoparticles measured by time-resolved small-angle x-ray scattering (TR-SAXS). Our results suggest that the kinetics for the formation of nanoparticles comprising ionic surfactants is much faster (in the range of milliseconds) than that for nanoparticles comprising nonionic surfactants (on the time scales of several seconds). We were able to observe the transformation of particle surface from transient structure to hard sphere one in real time. Some systems manifest a plethora of structural changes that demands further experimental research.
Real-time focal modulation microscopy

Focal modulation microscopy is a novel microscopy method that can achieve a large penetration depth with single photon excited fluorescence. In this method, excitation intensity within the focal volume is modulated by the use of a time dependent spatial phase modulator. The resultant fluorescence emission is filtered by the spatial gating provided by the pinhole and demodulated with a lock-in amplifier. Previous implementation of the spatial modulator is realised through a mechanical tilt plate phase modulator. This mechanical implementation affords stable modulation and provides satisfactory image quality. However, the slow modulation rate(in kHz range) depreciates the prospect of its employment in real time imaging. A new modulation scheme is proposed in which an acoustic optical modulator(AOM) is utilised. This new arrangement boost the modulation speed and makes real time imaging possible. We report on the development of such a modulation system together with the accompanying electronics. Images obtained with this new modulation system will also be presented
Current-monitoring method for measuring the electroosmotic flow rate in capillary zone electrophoresis

Capillary zone electrophoresis (CZE) is attracting much attention (1-4) as a new separation technique that can complement high-performance liquid chromatography (HPLC). In CZE a migration channel of capillary dimensions is filled with electrolyte; a sample to be analyzed is injected at one end of the channel; and a high voltage is applied across the channel. When the electrolyte contacts the walls of the capillary, the inner surface of the capillary becomes charged, either through the ionization of surface groups on the capillary walls or through the adsorption of charged species from the electrolyte onto the inner surface. In either case, the electrolyte inside the capillary is no longer electroneutral but acquires a net charge, which may be positive or negative. Under the action of the applied electric field, the electrolyte moves toward one end of the capillary, and this movement is referred to as electroosmotic (electroendosmotic) flow. In addition to the bulk flow of the electrolyte, electrophoresis also takes place; that is, the applied electric field exerts a force on positively charged species to cause them to move to the negatively charged electrode and on negatively charged species to cause them to move to the positively charged electrode. As a result, the components in the injected sample separate into distinct zones, based on their different mobilities. However, in many cases, the rate of electrophoretic flow is typically less than the rate of electroosmotic flow. Consequently, species in the injected sample move in one direction-the direction of the electroosmotic flow-and thus the different species can be detected as each zone passes through some suitable detector located downstream from the capillary inlet. Clearly, a precise characterization of the electroosmotic flow is highly desirable not only for understanding CZE but also for optimizing the operation of CZE in analyzing a given sample. One way to measure the electroosmotic flow rate is to record the elution time of an injected uncharged marker solute, which will be carried through the capillary under the action of only electroosmotic flow (4-6). For this purpose it is necessary that the marker solute be truly neutral, that it have negligible interaction with the capillary walls, and that it be readily detected. Another way is to weigh the mass of electrolyte transferred from the capillary inlet to the capillary outlet over a timed interval (7). For this purpose, losses caused by evaporation must be eliminated and the use of a digital balance appears to be recommended. Both of these procedures have been demonstrated to give reliable measurements of the electroosmotic flow rate, provided that some care is taken. We describe here what we believe might be a simpler procedure for measuring the electroosmotic flow rate. I t is based on recording the time history of the current during CZE operation. Thus the new method requires no special type of injected solute or detector, and it can be used by anyone carrying out CZE separations.