1,388 research outputs found
Development and investigation of implantable tablets for wound healing modulation after trabeculectomy
Modulation of wound healing is required to inhibit scar formation after trabeculectomy. Mitomycin C and 5-fluorouracil (5-FU) are the anti-proliferative drugs currently used in the clinic. Their effectiveness is limited due to their toxicity and suboptimal local tissue pharmacokinetics caused by rapid clearance within the subconjunctival space. Therefore, prolonged release of anti-scarring agents is needed. Ilomastat is a matrix metalloproteinase inhibitor that has been shown to moderate favorably the wound healing response after surgery. However, due to rapid local tissue clearance, several injections are necessary in a clinically relevant animal model.
The thesis describes the development and investigation of implantable ocular tablets for wound healing modulation after trabeculectomy. A tablet would be placed in the subconjunctival space called a bleb, which is caused by the outflow through the fistula made during surgery. While the bleb volume varies, the tablet is thought to dissolve in non-sink conditions. Tablet dissolution was evaluated in vitro using a flow chamber that mimics the liquid outflow conditions of the bleb. The in vitro release studies suggest that tablet dissolution would act to prolong drug release in comparison with injections. Tablet dissolution in the subconjunctival space is affected by many factors including the physical/chemical properties of the drug and tablet, temperature, the volume and flow rate of the dissolution media, and the surface area of the tablet. The efficacy of an excipient-free ilomastat tablet was evaluated using a clinically validated rabbit model. The tablet dissolution was examined using molecular dynamics simulations to consider the molecular interactions of ilomastat and 5-FU undergoing dissolution in non-sink conditions. A mathematical model was also developed to describe the dissolution of excipient-free tablets in the non-sink conditions with 94% confidence. In conclusion, we have established methods to investigate and simulate dissolution of excipientless tablets in non-sink conditions within the subconjunctival space
The Friedmann equation in modified entropy-area relation from entropy force
According to the formal holographic principle, a modification to the
assumption of holographic principle in Verlinder's investigation of entropy
force is obtained. A more precise relation between entropy and area in the
holographic system is proposed. With the entropy corrections to the
area-relation, we derivate Newton's laws and Einstein equation with a static
spherically symmetric holographic screen. Furthermore we derived the correction
terms to the modified Friedmann equation of the FRW universe starting from the
holographic principle and the Debye model.Comment: Mod. Phys. Lett. A26, 489-500 (2011
Quark deconfinement phase transition for improved quark mass density-dependent model
By using the finite temperature quantum field theory, we calculate the finite
temperature effective potential and extend the improved quark mass
density-dependent model to finite temperature. It is shown that this model can
not only describe the saturation properties of nuclear matter, but also explain
the quark deconfinement phase transition successfully. The critical temperature
is given and the effect of - meson is addressed.Comment: 18 pages, 7 figure
An analysis of the X-ray emission from the supernova remnant 3C397
The ASCA SIS and the ROSAT PSPC spectral data of the SNR 3C397 are analysed
with a two-component non-equilibrium ionization model. Besides, the ASCA SIS0
and SIS1 spectra are also fitted simultaneously in an equilibrium case. The
resulting values of the hydrogen column density yield a distance of \sim8\kpc
to 3C397. It is found that the hard X-ray emission, containing S and Fe
K lines, arises primarily from the hot component, while most of the
soft emission, composed mainly of Mg, Si, Fe L lines, and continuum, is
produced by the cool component. The emission measures suggest that the remnant
evolves in a cloudy medium and imply that the supernova progenitor might not be
a massive early-type star. The cool component is approaching ionization
equilibrium. The ages estimated from the ionization parameters and dynamics are
all much greater than the previous determination. We restore the X-ray maps
using the ASCA SIS data and compare them with the ROSAT HRI and the NRAO VLA
Sky Survey (NVSS) 20 cm maps. The morphology with two bright concentrations
suggests a bipolar remnant encountering a denser medium in the west.Comment: 20 pages, aasms4.sty, 3 figures To appear in ApJ (1999
Exraction and separation of CERIUM(IV)/FLUORINE in fluoride-bearing cerium sulfate solution with fluoride coordination agent
In this paper the extraction and separation of cerium/fluorine in fluoride-bearing cerium sulfate solution with fluoride coordination agent has been studied. The UV-vis spectra suggest that Zr6+ and Al3+ can scrub the F- from [CeF2] 2+ complex. The separation and conductivity studies show that aluminum salt is the most suitable fluoride coordination agent, and an ion-exchange reaction is involved between Ce4+/ [CeF2] 2+ and hydrogen ion
Exraction and separation of CERIUM(IV)/FLUORINE in fluoride-bearing cerium sulfate solution with fluoride coordination agent
In this paper the extraction and separation of cerium/fluorine in fluoride-bearing cerium sulfate solution with fluoride coordination agent has been studied. The UV-vis spectra suggest that Zr6+ and Al3+ can scrub the F- from [CeF2] 2+ complex. The separation and conductivity studies show that aluminum salt is the most suitable fluoride coordination agent, and an ion-exchange reaction is involved between Ce4+/ [CeF2] 2+ and hydrogen ion
Removal of fluoride from fluoride-bering cerium sulfate solution by hydrous zirconium oxide
In this paper the removal of fluoride from fluoride-bearing cerium sulfate solution by amorphous hydrous zirconium oxide was studied. The FTIR, SEM, EDS and UV-vis spectra show that fluoride is successfully adsorbed on hydrous zirconium oxide, and cerium exists as Ce4+ in solution. The study indicates that it is feasible to separate fluorine and cerium from fluorine-bearing rare earth sulfate solution using hydrous zirconium oxide, and eliminate the influence of fluoride on the extraction separation of rare earths
Association Between EEG Microarousal During Nocturnal Sleep and Next-Day Selective Attention in Mild Sleep-Restricted Healthy Undergraduates
Diguo Zhai,1,2 Qingwei Chen,1,2 Ying Yao,3 Taotao Ru,1,2 Guofu Zhou1,2 1Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, People’s Republic of China; 2National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, People’s Republic of China; 3Anhui Provincial Library, Hefei, 230000, People’s Republic of ChinaCorrespondence: Taotao Ru; Qingwei Chen, Lab of Light and Physio-Psychological Health-National Center for International Research on Green Optoelectronics-South China Academy of Advanced Optoelectronics-South China Normal University, No. 55, West Zhongshan Road, Tianhe District, Guangzhou, 510631, People’s Republic of China, Tel +86 15603063417 ; +86 15521094813, Email [email protected]; [email protected]: To explore whether sleep electroencephalogram (EEG) microarousals of different standard durations predict daytime mood and attention performance in healthy individuals after mild sleep restriction.Participants and Methods: Sixteen (nine female) healthy college students were recruited to examine the correlations between nocturnal EEG microarousals of different standard durations (≥ 3 s, ≥ 5 s, ≥ 7 s, ≥ 9 s) under mild sleep restriction (1.5 h) and the following morning’s subjective alertness, mood, sustained attention, and selective attention task performance.Results: Results revealed that mild sleep restriction significantly reduced subjective alertness and positive mood, while having no significant effect on negative mood, sustained attention and selective attention performance. The number of microarousals (≥ 5 s) was negatively associated with positive mood at 6:30. The number of microarousals was significantly and positively correlated with the response time difference value of disengagement component of the selective attention task at around 7:30 (≥ 5 s and ≥ 7 s) and 9:00 (≥ 5 s). The number of microarousals (≥ 7 s) was significantly and positively correlated with the inaccuracy difference value of orientation component of the selective attention task at around 9:00.Conclusion: The number of EEG microarousals during sleep in healthy adults with mild sleep restriction was significantly and negatively related to their daytime positive affect while positively associated with the deterioration of disengagement and orientation of selective attention performance, but this link is dependent on the standard duration of microarousals, test time and the type of task.Keywords: microarousal, alertness, sustained attention, selective attention, sleep restrictio
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