Previous analyses from a randomised trial in women aged 24-45 years have shown the quadrivalent human papillomavirus (qHPV) vaccine to be efficacious in the prevention of infection, cervical ...intraepithelial neoplasia (CIN), and external genital lesions (EGLs) related to HPV 6/11/16/18. In this report, we present end-of-study efficacy, safety, and immunogenicity data with a median follow-up time of 4.0 years.
We enrolled 3819 24-45-year-old women with no history of cervical disease or genital warts in the past 5 years. Women received quadrivalent vaccine or placebo at day 1, and at months 2 and 6. Ascertainment of CIN/EGL was accomplished through Pap testing, genital inspection, and cervicovaginal sampling (every 6 months). The main analysis was conducted in a per-protocol efficacy population (that received three doses, was naive to the relevant HPV types at day 1, and remained free of infection through month 7). Efficacy was also estimated in other naive and non-naive populations.
Vaccine efficacy against the combined incidence of persistent infection, CIN/EGL related to HPV6/11/16/18 in the per-protocol population was 88.7% (95% CI: 78.1, 94.8). Efficacy for women who were seropositive and DNA negative for the relevant vaccine HPV type at the time of enrolment who received at least 1 dose was 66.9% (95% CI: 4.3, 90.6). At month 48, 91.5, 92.0, 97.4, and 47.9% of vaccinated women were seropositive to HPV 6/11/16/18, respectively. No serious vaccine-related adverse experiences were reported.
The qHPV vaccine demonstrated high efficacy, immunogenicity, and acceptable safety in women aged 24-45 years, regardless of previous exposure to HPV vaccine type.
We theoretically analyze the interaction between a viscoelastic fluid flow, whose constitutive equation is the simplified Phan–Thien–Tanner model, and a deformable slender shallow microchannel. The ...microchannel top wall displacement is analyzed considering two cases: a) as a thin plate, using the Kirchhoff–Love theory, and b) as a thick plate, based on the Reissner–Mindlin theory. The mathematical model is nondimensionalized, and dimensionless parameters related to problem physics arise that control the fluid–structure interaction. The governing equations that describe the hydrodynamic field are simplified using the lubrication theory, and the displacement of the top wall is analyzed for each plate theory, relating the hydrodynamic pressure and the volumetric flow rate. These equations are implicit in the pressure and are solved numerically. The effect of dimensionless parameters on the pressure drop-volumetric flow rate relationship is analyzed, showing that for a viscoelastic fluid flowing through deformable channels, the volumetric flow rate is higher than the case of a Newtonian fluid under the same pressure. Our results are compared against those published in the specialized literature, showing an excellent agreement.
•Fluid–structure interaction between a microchannel and sPTT fluid flow is studied.•The fluid rheology is described by the simplified Phan-Thien-Tanner (sPTT) model.•The relationship pressure drop-volumetric flow rate is determined.•Thin and thick plates theories for the microchannel soft top wall are considered.•As the viscoelasticity of the fluid increases, higher volumetric flows are achieved.
RESUMEN El uso de medidas de control no contaminante se ha incrementado en los últimos años, permitiendo reducir la aplicación de agroquímicos que afectan el medio ambiente. En este trabajo se evaluó ...las técnicas de biofumigación, solarización y bio-solarización en la producción de pepino americano, bajo condiciones de invernadero. La biofumigación es una técnica que utiliza materia orgánica, para el control de patógenos del suelo; mientras que la solarización consiste en el calentamiento del suelo a temperaturas tales que permiten el control de plagas y enfermedades; en tanto que a la combinación de ambas técnicas (biofumigación+solarización) se le denomina biosolarización. El experimento se desarrolló en un invernadero ubicado en el campo experimental del Departamento de Agricultura y Ganadería de la Universidad de Sonora, en Hermosillo, Sonora, México. El diseño fue de bloques al azar con cuatro tratamientos y cuatro repeticiones. Los tratamientos evaluados fueron: biofumigación, solarización, biosolarización y el testigo. Las variables evaluadas fueron: rendimiento (kg m-2, cajas ha-1 y frutos planta-1) y peso del fruto (g). Como parámetros de calidad se cuantificó la firmeza del fruto en kg cm-2, al igual que la longitud y el diámetro en cm. El mejor tratamiento fue la biofumigación, el que presentó un mayor número de frutos con 10,1 frutos planta-1 y un mayor rendimiento con 10,0 kg m-2 y 4.197 cajas ha-1; seguido por la biosolarización, con 9,3 frutos planta-1 y un rendimiento de 8,7 kg m-2 y 3.791 cajas ha-1. Los parámetros de calidad no presentaron diferencias significativas entre tratamientos.
The dispersion coefficient of a passive solute in a steady-state pure electro-osmotic flow (EOF) of a viscoelastic liquid, whose rheological behaviour follows the simplified Phan-Thien–Tanner (sPTT) ...model, along a parallel flat plate microchannel, is studied. The walls of the microchannel are assumed to have modulated and low
$\unicodeSTIX{x1D701}$
potentials, which vary slowly in the axial direction in a sinusoidal manner. The flow field required to obtain the dispersion coefficient was solved using the lubrication approximation theory (LAT). The solution of the electric potential is based on the Debye–Hückel approximation for a symmetric
$(z:z)$
electrolyte. The viscoelasticity of the fluid is observed to notably amplify the axial distribution of the effective dispersion coefficients due to the variation in the
$\unicodeSTIX{x1D701}$
potentials of the walls. The problem was formulated for two cases: when the Debye layer thickness (EDL) was on the order of unity (thick EDL) and in the limit where the thickness of the EDL was very small compared with the height of the microchannel (thin EDL limit). Due to the coupling between the nonlinear governing equations and the sPTT fluid model, they were replaced by their approximate linearized forms and solved in the limit of
$\unicodeSTIX{x1D700}\ll 1$
using the regular perturbation technique. Here
$\unicodeSTIX{x1D700}$
is the amplitude of the sinusoidal function of the
$\unicodeSTIX{x1D701}$
potentials. Additionally, the numerical solution of the simplified governing equations was also obtained for
$\unicodeSTIX{x1D700}=O(1)$
and compared with the approximate solution, showing excellent agreement for
$0\leqslant \unicodeSTIX{x1D700}\leqslant 0.3$
. Note that the dispersion coefficient primarily depends on the Deborah number, on the ratio of the half-height of the microchannel to the Debye length, and on the assumed variation in the
$\unicodeSTIX{x1D701}$
potentials of the walls.
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The present study analyzes the combined viscoelectric and steric effects on the electroosmotic flow of Newtonian fluids in nano/microchannels. The governing equations that describe ...the flow field are the modified Poisson-Boltzmann equation for the electric potential, the mass conservation and momentum equations, which are solved numerically. On the channel walls, arbitrary and heterogeneous zeta potentials modulated via sinusoidal functions are imposed, being controlled by a phase angle, an amplitude and a wave number. The use of arbitrary zeta potentials leads to the study of the viscoelectric effect due to the fact that the viscosity near the walls of the channel increases drastically. Also, the presence of high ionic concentrations and large effective ionic sizes causes an excluded volume of the crowding of ions into the electric double layer; in this manner, the study of the steric effect is relevant in the present work. The results show that the viscoelectric effect produces a reduction in the magnitude of the velocity profiles when zeta potentials are magnified. On the contrary, the steric effect counteracts the aforementioned effect, increasing the velocity of the flow. In addition, the heterogeneous zeta potentials at the walls generate an induced pressure and recirculations on the flow. In particular, when the wave number is even leads to a condition with null volumetric flow rate; while for an odd wave number, a favorable volumetric flow rate is generated. This study extends the knowledge of electroosmotic flows under field effects for future mixing applications.
•Mass transport of a neutral solute in a pulsatile electroosmotic flow is studied.•Asymmetric zeta potentials of the microchannel walls are considered.•Velocity and concentration fields are ...analytically determined.•Effective dispersion coefficient is derived in terms of the angular Reynolds number.
In this work, we analyze theoretically the mass transport of a neutral solute in a pulsatile electroosmotic flow (PEOF), circulating in a parallel flat plate microchannel whose walls are characterized by asymmetric zeta potentials. The microchannel is connected to a two reservoirs having different concentrations. To analyze the mass transport in the PEOF, the Debye-Hückel approximation is assumed, and the electric potential in the Debye length is obtained from the Poisson-Boltzmann equation. Then, using the momentum and concentration equations, the flow and concentration fields are analytically determined for the periodic stage. Such field distributions depend principally on three dimensionless parameters: an angular Reynolds number, the Schmidt number, and the ratio between the half height of the channel and the Debye length. For obtaining insight on the physical aspects of the studied phenomenon, an asymptotic solution is additionally obtained in the limits of small and large values of the angular Reynolds number. Some important results derived from this analysis show the conditions for which the mass transport of a neutral solute can be enhanced and the circumstances whereby mixing of species is achieved.
•Mass transport by oscillatory electroosmotic flow in a microannulus is analyzed.•Oscillatory electroosmotic flow of a Maxwell fluid is considered.•Separation of electro neutral species is ...studied.•Conditions for better mixing and separation of species are found.
In this work we develop a theoretical analysis for the mass transfer of an electroneutral solute in a concentric-annulus microchannel driven by an oscillatory electroosmotic flow (OEOF) of a fluid whose behavior follows the Maxwell model. The annular microchannel connects two reservoirs that have different concentrations of the solute. For the mathematical modeling of the OEOF, we assume the Debye-Hückel approximation and that the wall zeta potentials of the micro-annulus can be symmetric or asymmetric. The governing equations are nondimensionalized, from which the following dimensionless parameters appear: an angular Reynolds number, the ratio of the wall zeta potentials of the annular microchannel, the electrokinetic parameter, the dimensionless gap between the two cylinders, the Schmidt number and the elasticity number. The results indicate that the velocity and concentration distributions across the annular microchannel become non-uniform as the angular Reynolds number increases, and depend notably on the elasticity number. It is also revealed that with a suitable combination of values of the elasticity number and gap between the two cylinders, together with the angular Reynolds number, the total mass transport rate can be increased and the species separation can be controlled.
In this work, we theoretically analyze how a passive solute is transported by an oscillating electro-osmotic flow along a parallel flat plate microchannel connecting two reservoirs with different ...concentrations. Three distinct periodic functions of the applied external electric field are considered: sawtooth, square, and parabolic waveforms, which are expressed as Fourier series. For each case, the dimensionless velocity and concentration fields are found analytically and, subsequently, the transport of the solute was obtained numerically. We distinguish four dimensionless parameters that govern the studied phenomenon: an angular Reynolds number, the Schmidt and Péclet numbers, and an electrokinetic parameter, this latter representing the ratio of the half-height of the microchannel to the Debye length. As has been reported in the specialized literature, the mass transport and separation of species in oscillating flows under the effect of an oscillatory pressure gradient can be increased with the angular frequency. For the present study, instead of a pressure gradient, we use oscillatory electro-osmotic forces, together with symmetric and asymmetric wall zeta potentials in the microchannel. For this condition, we prove that the transport of the solute is affected notably. In this paper, we show that controlling the type of the external electrical signal can also improve the mentioned tasks, depending on the Schmidt number, the electrokinetic parameter, and the angular Reynolds number.
•The energy equation is extended for including the ionic displacement due to advection, diffusion, and thermodiffusion effects.•The coupled set of the Poisson-Boltzmann, momentum and energy equations ...were simplified in the limit of the lubrication approximation theory and solved numerically using the SIMPLE algorithm and the ADI method.•Thermodiffusion causes adverse and favorable pressure gradients given rise to concave and convex shapes of the velocity profiles.•Joule heating causes an axial and transversal ionic rearrangement and distortions of the hydrodynamics field.•Thermodiffusion modifies the hydrodynamics of the electroosmotic flow, causing that the local Debye length varies in the axial direction of the microchannel.
This work theoretically studies the influence of the thermodiffusive effect on the local Debye length thickness in a purely electroosmotic flow in a parallel flat plate microchannel. An imposed electric field between the ends of the microchannel interacts with an ionized viscoelastic fluid causing Joule heating, which induces a temperature gradients along the microchannel, affecting the fluid’s physical properties, and in a notable manner, the ionic distribution into the electric double layer (EDL), resulting in thermodiffusion. Consequently, an induced pressure field counterbalances the axial variation of the plug-like electroosmotic velocity to maintain the fluid mass continuity. Also, the ionic distribution and electrical potential based on the non-isothermal Poisson-Boltzmann equation are modified. To estimate the local Debye length thickness, the coupled set of the Poisson-Boltzmann, momentum, and energy equations are solved numerically in the limit of the lubrication approximation theory (LAT). Our results indicate that the thermodiffusion has an important effect on the thickness of the local Debye-length, particularly in the warm zone of the fluid. Besides, the ionic response to thermal fields is given by a positive Soret coefficient, which indicates that the ionic particles move from warm to cold regions in the fluid, giving place to a thinner Debye length and lower ionic concentration around the warming zone; this migration of ions confirms that the dimensionless mass-flow rate is affected with the Soret coefficient compared with the non-thermodiffusion case.
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