330 research outputs found
Preparation and Evaluation of Intravaginal Ring Containing Drospirenone
In the present study, we investigated the feasibility of the vaginal administration of drospirenone silicone IVR. The in vitro release characteristics of matrix-type and reservoir-type IVR were compared under sink conditions in 21 days. At the same time, API excipients compatibility and preformulation study was performed by HPLC, IR, and DSC methods. Biocompatibility of reservoir system was evaluated by tolerability on tissue level in rats. It was found that, under strong light exposure, high temperature, and high humidity conditions, drospirenone and excipients had no significant interactions. The daily release of reservoir-type IVR was about 0.5 mg/d sustaining 21 days, which significantly decreased the burst effect compared with the matrix system. When drospirenone was modified by the PVPk30 in the reservoir system formulation, the daily release rate increased to 1.0 mg/d sustaining 21 days. The cumulative release of reservoir-type IVR was fitted to zero release equation. In addition, biocompatibility of drospirenone IVR system in this dosage is safe. It is feasibility feasibile to further developed for safe, convenient, and effective contraceptive drug delivery with reduced dosing interval
Amplification of rotation velocity using weak measurements in Sagnac's interferometer
We study the amplification of rotation velocity with the Sagnac
interferometer based on the concept of weak-value amplification. By using a
different scheme to perform the Sagnac interferometer with the probe in
momentum space, we have demonstrated the new weak measure protocol to detect
the small rotation velocity by amplifying the phase shift of the Sagnac effect.
At the given the maximum incident intensity of the initial spectrum, the
detection limit of the intensity of the spectrometer and the accuracy of
angular velocity measurement, we can theoretical give the appropriate
potselection and the minimum of optical path area before experiment. In
addition, we put forward a new optical design to increase the optical path area
and decrease the size of the interferometer to overcome the limit of instrument
size. Finally, our modified Sagnac's interferometer based on weak measurement
is innovative and efficient probing the small rotation velocity signal.Comment: arXiv admin note: text overlap with arXiv:1203.0827 by other author
The design of a new fiber optic sensor for measuring linear velocity with pico meter/second sensitivity based on Weak-value amplification
We put forward a new fiber optic sensor for measuring linear velocity with
picometer/second sensitivity with Weak-value amplification based on generalized
Sagnac effect [Phys. Rev. Lett.\textbf{93}, 143901(2004)].The generalized
Sagnac effect was first introduced by Yao et al, which included the Sagnac
effect of rotation as a special case and suggested a new fiber optic sensor for
measuring linear motion with nanoscale sensitivity. By using a different scheme
to perform the Sagnac interferometer with the probe in momentum space, we have
demonstrated the new weak measure protocol to detect the linear velocity by
amplifying the phase shift of the generalized Sagnac effect. Given the maximum
incident intensity of the initial spectrum, the detection limit of the
intensity of the spectrometer, we can theoretically give the appropriate
pre-selection, post-selection, and other optical structures before the
experiment. Our numerical results show our scheme with Weak-value amplification
is effective and feasible to detect linear velocity with picometer/second
sensitivity which is three orders of magnitude smaller than the result
=4.8 m/s obtained by generalized Sagnac effect with
same fiber length.Comment: 3 figures; 9 pages. arXiv admin note: substantial text overlap with
arXiv:2105.1363
nonlocal quark condensate from Dyson-Schwinger Equation and its contributions to the gluon vacuum polarization based on OPE approach
The operator-product expansion(OPE) could be employed to obtain the
lowest-order, nonlocal quark scalar condensate component of gluon vacuum
polarization. In particular, nonlocal quark scalar condensate can be calculated
by solving Dyson-Schwinger Equation(DSE) of QCD. Then, field-theoretic aspects
of the gluon vacuum polarization and nonperturbative gluon propagator will be
considered in the Landau gauge of the Lorentz gauge fixing. The gluon
propagator we obtained is finite in the infrared domain where the single gluon
mass can be determined. Our results of the ratio
the range of that from 1.33 to 1.39 agree with previous determinations for this
ratio. Besides, the analytic structure of the gluon propagators from the OPE's
result is explored. Our numerical analysis of the gluon' Schwinger function
finds clear evidence of the positivity violations in the gluon propagator. In
addition, a new method for obtaining the chemical potential dependence of the
gluon vacuum polarization and the dressed gluon propagator is developed.Comment: 9 pages, 14 figures
A potential third-generation gravitational-wave detector based on autocorrelative weak-value amplification
Reducing noises and enhancing signal-to-noise ratios (SNRs) have become
critical for designing third-generation gravitational-wave (GW) detectors with
a GW strain of less than /. In this paper, we propose
a potential third-generation GW detector based on autocorrelative weak-value
amplification (AWVA) for GW detection with a strain of /. In our scheme, a GW event induces a phase difference
by passing through an 11-bounce delay line, 10-km arm-length,
zero-area Sagnac interferometer illuminated with a 1064-nm laser. Subsequently,
is amplified as the parameter of post-selection by choosing the
appropriate pre-selected state and coupling strength in AWVA. In particular, we
theoretically investigate the AWVA measurements for GW detection within the
frequency band of 200 Hz 800 Hz, considering Gaussian
noises with negative-decibel SNRs. The peak response of the AWVA sensitivity
occurs at frequency = 500 Hz, which falls within the
frequency band of interest of the current third-generation GW detectors. Our
simulation results indicate that AWVA can demonstrate a measurable sensitivity
of within the frequency band of interest. Moreover, the
robustness of WVA shows promising potential in mitigating the effects of
Gaussian noises.Comment: 21 pages, 6 figure
Auto-correlative weak-value amplification under strong noise background
In the general optical metro-logical protocols based on the weak-value
amplification(WVA) approach, it is beneficial to choose the pre-selected state
and the post-selected one to be nearly orthogonal for improving the
sensitivity. However, the orthogonality of the post-selection decreases the
probability of detecting photons and makes the weak measurement difficult,
especially when there is strong noise background and the pointer is drowned in
noise. In this article, we investigate a modified weak measurement protocol
with a temporal pointer, namely, the auto-correlative weak-value amplification
(AWVA) approach. We find it can significantly improve the precision of optical
metrology under Gaussian white noise, especially with a negative
signal-to-noise ratio. With the AWVA approach, a small longitudinal time delay
(tiny phase shift) of a Gaussian pulse is measured by implementing two
auto-correlative weak measurements. The small quantities are obtained by
measuring the auto-correlation coefficient of the pulses instead of fitting the
shift of the mean value of the probe. Simulation results show that the AWVA
approach outperforms the standard WVA technique in the time domain, remarkably
increasing the precision of weak measurement under strong noise background.Comment: 15 pages, 10 figure
A Facile Strategy for the Fabrication of Cell-Laden Porous Alginate Hydrogels based on Two-Phase Aqueous Emulsions
Porous alginate (Alg) hydrogels possess many advantages as cell carriers. However, current pore generation methods require either complex or harsh fabrication processes, toxic components, or extra purification steps, limiting the feasibility and affecting the cellular survival and function. In this study, a simple and cell-friendly approach to generate highly porous cell-laden Alg hydrogels based on two-phase aqueous emulsions is reported. The pre-gel solutions, which contain two immiscible aqueous phases of Alg and caseinate (Cas), are cross-linked by calcium ions. The porous structure of the hydrogel construct is formed by subsequently removing the Cas phase from the ion-cross-linked Alg hydrogel. Those porous Alg hydrogels possess heterogeneous pores ≈100 μm and interconnected paths. Human white adipose progenitors (WAPs) encapsulated in these hydrogels self-organize into spheroids and show enhanced viability, proliferation, and adipogenic differentiation, compared to non-porous constructs. As a proof of concept, this porous Alg hydrogel platform is employed to prepare core-shell spheres for coculture of WAPs and colon cancer cells, with WAP clusters distributed around cancer cell aggregates, to investigate cellular crosstalk. This efficacious approach is believed to provide a robust and versatile platform for engineering porous-structured Alg hydrogels for applications as cell carriers and in disease modeling
Investigation of the morbidity of dry eye among special crowd in Shunde district
AIM: To investigate the morbidity of dry eye in policeman of Shunde district, and to analyze the related factors and proposed methods of preventing and treating dry eye.<p>METHODS:Totally 650 policemen who came for physical examination in Shunde district recived questionnaire survey. The patients with dye eye disease were finally diagnosed through slit lamp examination, Schirmer test, tear film break-up time(BUT)measurement and keratoconjunctival fluorescent staining. The morbidity among different policemen was further analyzed and stasticed.<p>RESULTS:The results showed that 152 in 650 policemen suffered from dry eye disease, the ratio was 23.4%. Comparied with security police and crimanl police, the ratio in traffic police, patrolman,and back office police was significantly higher. The prevalence was higher when the ages were greater than 40.<p>CONCLUSION: Unsuitable working environment, air contamination are high risk factors of dry eye disease
A Facile Strategy for the Fabrication of Cell-Laden Porous Alginate Hydrogels based on Two-Phase Aqueous Emulsions
Porous alginate (Alg) hydrogels possess many advantages as cell carriers. However, current pore generation methods require either complex or harsh fabrication processes, toxic components, or extra purification steps, limiting the feasibility and affecting the cellular survival and function. In this study, a simple and cell-friendly approach to generate highly porous cell-laden Alg hydrogels based on two-phase aqueous emulsions is reported. The pre-gel solutions, which contain two immiscible aqueous phases of Alg and caseinate (Cas), are cross-linked by calcium ions. The porous structure of the hydrogel construct is formed by subsequently removing the Cas phase from the ion-cross-linked Alg hydrogel. Those porous Alg hydrogels possess heterogeneous pores ≈100 µm and interconnected paths. Human white adipose progenitors (WAPs) encapsulated in these hydrogels self-organize into spheroids and show enhanced viability, proliferation, and adipogenic differentiation, compared to non-porous constructs. As a proof of concept, this porous Alg hydrogel platform is employed to prepare core-shell spheres for coculture of WAPs and colon cancer cells, with WAP clusters distributed around cancer cell aggregates, to investigate cellular crosstalk. This efficacious approach is believed to provide a robust and versatile platform for engineering porous-structured Alg hydrogels for applications as cell carriers and in disease modeling
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