Purpose: Thickening polymers have been used as excipients in nasal formulations to avoid nasal run-off (nasal drip) post-administration. However, increasing the viscosity of the formulation can have a negative impact on the quality of the aerosols generated. Therefore, the study aims to investigate the use of a novel smart nano-cellulose excipient to generate suitable droplets for nasal drug delivery that simultaneously has only marginally increased viscosity while still reducing nasal drips.
Methods: Nasal sprays containing nano-cellulose at different concentrations were investigated for the additive’s potential as an excipient. The formulations were characterized for their rheological and aerosol properties. This was then compared to conventional nasal spray formulation containing the single-component hydroxyl-propyl methyl cellulose (HPMC) viscosity enhancing excipient.
Results: The HPMC-containing nasal formulations behave in a Newtonian manner while the nano-cellulose formulations have a yield stress and shear-thinning properties. At higher excipient concentrations and shear rates, the nano-cellulose solutions have significantly lower viscosities compared to the HPMC solution, resulting in improved droplet formation when actuated through conventional nasal spray.
Conclusions: Nano-cellulose materials could potentially be used as a suitable excipient for nasal drug delivery, producing consistent aerosol droplet size, and enhanced residence time within the nasal cavity with reduced run-offs compared to conventional polymer thickeners. 相似文献
Inspired by the highly versatile natural motors, artificial micro‐/nanomotors that can convert surrounding energies into mechanical motion and accomplish multiple tasks are devised. In the past few years, micro‐/nanomotors have demonstrated significant potential in biomedicine. However, the practical biomedical applications of these small‐scale devices are still at an infant stage. For successful bench‐to‐bed translation, biocompatibility of micro‐/nanomotor systems is the central issue to be considered. Herein, the recent progress in micro‐/nanomotors in biocompatibility is reviewed, with a special focus on their biomedical applications. Through close collaboration between researches in the nanoengineering, material chemistry, and biomedical fields, it is expected that a promising real‐world application platform based on micro‐/nanomotors will emerge in the near future. 相似文献
One of the hardest points in context-aware applications is deciding what reactions a system has to a certain context. In
this paper, we introduce an architecture used in two context-aware museum guides. We discuss how the context is modelled and
we briefly present a rule-based mechanism to trigger system actions. A rule-based system offers the flexibility required to
be context-sensitive in the broadest sense since many context features can be considered and evaluated at the same time. This
architecture is very flexible and easily supports a fast prototyping approach. 相似文献
This paper concerns mixed-initiative interaction between users and agents. After classifying agents according to their task and their interactivity with the user, the critical aspects of delegation-based interaction are outlined. Then MASMA, an agent system for distributed meeting scheduling, is described, and the solutions developed to control interaction are explained in detail. The issues addressed concern: the agent capability of adapting its behavior to the user it is supporting; the solution adopted to control the shift of initiative between personal agents, their users and other agents in the environment; the availability of features, e.g. the inspection mechanism, that endow the user with a further level of control to enhance his sense of trust in the agent. 相似文献
Groundwater investigations in Linz have shown, that the temperature in the groundwater reservoir has increased significantly compared to the temperature of the environment. To investigate whether the existing groundwater facilities for cooling have a quantifiable impact on groundwater temperatures all given permissions regarding groundwater usage for cooling premises were analyzed in detail. Therefore data on the yearly amount and type of groundwater usage were collected and sorted for further analyses. Based on these data the length and the width of the temperature flags in the groundwater reservoir were calculated with the thermal formula of Ingerle (1988), modified by Rauch (1992) and corresponding to the ÖVAW technical rule 207. The temperature flags of every groundwater user with cooling purposes were visualized with the software ARCMAP 10.1 and compared with real data from field measurements. Furthermore an analyses of uncertainty for the length of the temperature flags was involved in the study. With this method the areas where a thermic impact to the groundwater reservoir is of a high likelihood because of existing groundwater usage for cooling purposes were identified. Based on this in a next step different alternatives for district cooling were developed involving both central (covering all existing groundwater users) and semi central (covering only parts of existing users) solutions. To compare and evaluate the difference an efficiency analysis was undertaken. In this article the calculation and results of the thermal flag analysis of all relevant groundwater users are presented. Two of the seven alternatives for district cooling are then introduced more detailed. Further the efficiency analysis of the different alternatives is described using economical, ecological and social criteria. 相似文献
Accurate assessment of phytoplankton chlorophyll-a (chla) concentrations in turbid waters by means of remote sensing is challenging due to the optical complexity of case 2 waters. We have applied a recently developed model of the form [Rrs? 1(λ1) ? Rrs? 1(λ2)] × Rrs(λ3) where Rrs(λi) is the remote-sensing reflectance at the wavelength λi, for the estimation of chla concentrations in turbid waters. The objectives of this paper are (a) to validate the three-band model as well as its special case, the two-band model Rrs? 1(λ1) × Rrs(λ3), using datasets collected over a considerable range of optical properties, trophic status, and geographical locations in turbid lakes, reservoirs, estuaries, and coastal waters, and (b) to evaluate the extent to which the three-band model could be applied to the Medium Resolution Imaging Spectrometer (MERIS) and two-band model could be applied to the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate chla in turbid waters.The three-band model was calibrated and validated using three MERIS spectral bands (660–670 nm, 703.75–713.75 nm, and 750?757.5 nm), and the 2-band model was tested using two MODIS spectral bands (λ1 = 662–672, λ3 = 743–753 nm). We assessed the accuracy of chla prediction in four independent datasets without re-parameterization (adjustment of the coefficients) after initial calibration elsewhere. Although the validation data set contained widely variable chla (1.2 to 236 mg m? 3), Secchi disk depth (0.18 to 4.1 m), and turbidity (1.3 to 78 NTU), chla predicted by the three-band algorithm was strongly correlated with observed chla (r2 > 0.96), with a precision of 32% and average bias across data sets of ? 4.9% to 11%. Chla predicted by the two-band algorithm was also closely correlated with observed chla (r2 > 0.92); however, the precision declined to 57%, and average bias across the data sets was 18% to 50.3%. These findings imply that, provided that an atmospheric correction scheme for the red and NIR bands is available, the extensive database of MERIS and MODIS imagery could be used for quantitative monitoring of chla in turbid waters. 相似文献
Studies of computational scientists developing software for high-performance computing systems indicate that these scientists face unique software engineering issues. Previous failed attempts to transfer SE technologies to this domain haven't always taken these issues into account. To support scientific-software development, the SE community can disseminate appropriate practices and processes, develop educational materials specifically for computational scientists, and investigate the large-scale reuse of development frameworks. 相似文献
A simple and novel potentiometric biosensor for urea detection was prepared by employing an electrosynthesized polymer with buffering capability. It was obtained by deposition of a weighed amount of urease (Ur) at a glassy carbon (GC) electrode followed by immobilization by an electrosynthesized poly-o-phenylenediamine (PPD) film. An unconventional “upside-down” (UD) geometry was employed for the electrochemical cell. The response of GC/Ur/PPD sensor is linear with urea concentration in the range 10 μM to 1 mM (15 mV/mM, R2 = 0.9999) due to buffering capability of PPD film, which represents a novel role of electrosynthesized polymers in their application to biosensors. At higher concentrations, the more common Nernstian response (28 mV/decade, R2 = 0.9987) is observed. The sensor exhibits a sufficient sensitivity for practical determinations, rapid response and long term stability. 相似文献