Tail Model Research Articles

Effective Disinfection of Rough Rice Using Infrared Radiation Heating

The objective of this study was to investigate the effect of infrared (IR) heating and tempering treatments on disinfection of Aspergillus flavus in freshly harvested rough rice and storage rice. Rice samples with initial moisture contents (IMCs) of 14.1 to 27.0% (wet basis) were infected with A. flavus spores before the tests. The infected samples were heated by IR radiation to 60°C in less than 1 min, and then samples were tempered at 60°C for 5, 10, 20, 30, 60, or 120 min. High heating rates and corresponding high levels of moisture removal were achieved using IR heating. The highest total moisture removal was 5.3% for the fresh rice with an IMC of 27.0% after IR heating and then 120 min of tempering. IR heating followed by tempering for 120 min resulted in 2.5- and 8.3-log reductions of A. flavus spores in rough rice with the lowest and highest IMCs, respectively. To study the effect on disinfection of rewetting dried storage rice, the surface of the dry rice was rewetted to achieve IMCs of 14.7 to 19.4% (wet basis). The rewetting process for the dry rice had a significant effect on disinfection. IR heating followed by tempering for 60 min resulted in 7.2-log reductions in A. flavus on rewetted rough rice. The log-linear plus tail model was applied to estimate the tempering time needed to achieve a 5-log reduction of A. flavus in rice of different IMCs. At least 30 and 20 min of tempering were needed for fresh rice and rewetted rice, respectively, with the highest IMCs. The recommended conditions of simultaneous disinfection and drying for fresh rice was IR heating to 60°C followed by tempering for 120 min and natural cooling, resulting in a final MC of 16.5 to 22.0%, depending on the IMC. For the rewetted dry rice with an IMC of 19.4%, the recommended condition for disinfection and drying involved only 20 min of tempering. The final MC of the sample was 13.8%, which is a safe MC for storage rice.

ON THE DUST ENVIRONMENT OF COMET C/2012 S1 (ISON) FROM 12 AU PRE-PERIHELION TO THE END OF ITS ACTIVITY AROUND PERIHELION

A Monte Carlo dust tail model has been applied to extract the dust environment parameters of the comet C/2012 S1 (ISON) from both Earth-based and SOHO LASCO C3 observations, performed from about six astronomical units (AU) inbound, to just after perihelion passage, when only a small portion of the original comet nucleus has survived in the form of a cloud of tiny particles. The early Afρ and image data are consistent with particle ejection from an extended active area located at latitudes 35°N to 90°N (for a prograde rotating nucleus), with the spin axis having a large obliquity (I ∼ 70°). This configuration nicely fits the early images and Afρ data until 3.9 AU inbound, when the emission should become isotropic in order to fit the data. The analysis of LASCO images reveals that, assuming an original nucleus of R{sub N} = 500 m with ρ = 1000 kg m{sup –3}, at least half of its mass was vaporized when the comet was at about 17 R {sub ☉} inbound. We conclude that at that time the nucleus suffered a cataclysmic fragmentation releasing a huge amount of material of 2.3 ×10{sup 11} kg, equivalent to a sphere of 380 m more » in radius with density 1000 kg m{sup –3}. The surviving material after perihelion passage consists of very small dust particles of 0.1-50 μm in radius with a total mass of just 6.7×10{sup 8} kg. « less

Topical bFGF Improves Secondary Lymphedema through Lymphangiogenesis in a Rat Tail Model.

Background:Secondary lymphedema is a common complication of cancer therapy, but options for treating lymphedema are essentially ineffective and limited. On the contrary, lymphangiogenic growth factors accelerate lymphangiogenesis and improve lymphedema.Methods:Rat tail models of lymphedema were assigned to groups that received either daily topical basic fibroblast growth factor (bFGF) or saline (control) groups. Tail volume was measured, and the function of the lymphatic system was evaluated as the fluorescence intensity of indocyanine green every 3 days. The mRNA levels of vascular endothelial growth factor (VEGF)-C and VEGF-D and the protein levels of VEGF-C were evaluated at postoperative days (PODs) 7, 14, and 28. The subcutaneous and deep areas and lymphatic vessel density were histologically determined at PODs 7, 14, and 28.Results:Tail volume was significantly larger in the control than in the bFGF group (P < 0.05). The intensity of indocyanine green fluorescence significantly decreased earlier in the bFGF group (P < 0.05). The mRNA and protein levels of VEGF-C were upregulated in the bFGF group at POD 14 (P < 0.01). Both subcutaneous and deep tissues gradually withered in both groups but more rapidly in the bFGF, than in the control group, reaching statistically significant differences in the subcutaneous and deeper areas at POD 14 (P < 0.05). Lymphatic vessel density was significantly higher in the bFGF than in the control group at POD 14 (P < 0.05).Conclusions:Topical bFGF induces lymphangiogenesis and improves lymphedema in the rat tail model.

Extended focused information criterion for censored quantile regression model and averaging estimation

In this paper,we extend Claeskens and Hjort's focused information criterion(FIC) for the censored linear model based on quantile regression,and propose an extended FIC for focused vector.We model different quantiles of the censored response to depict the comprehensive character of the distribution of the response and deal with outliers and heavy tailed model error.We further develop a model selection and averaging estimation procedure based on the extended focused information criterion and show the asymptotical property of the proposed estimators.We conduct a simulation study to detect the behavior of the proposed method compared with least square based method with finite sample sizes and analyze the primary biliary cirrhosis data set to illustrate the proposed method in applications.

Solid lipid nanoparticles-loaded topical gel containing combination drugs: an approach to offset psoriasis

Aim: The primary aim of present work was to develop effective combination drug therapy for topical treatment of psoriasis.Methods: Betamethasone dipropionate and calcipotriol loaded solid lipid nanoparticles (CT-BD-SLNs) were prepared by hot melt high shear homogenization technique, which were then incorporated in Carbopol gel matrix. The anti-psoriatic potential was tested by sequential in vitro (skin permeation and dermal distribution, anti-proliferative effect in HaCaT cells) and in vivo (Draize patch irritation, transepidermal water loss (TEWL) and anti-psoriatic mouse tail studies) experiments.Results: A negligible amount in receptor compartment, yet confined distribution of drugs to epidermal and dermal region of skin was observed in case of SLNs, which is essential for safe and effective anti-psoriatic therapy. Draize patch test and TEWL demonstrated negligible skin irritation and better skin tolerability of SLNs. The in vitro HaCaT cell line study demonstrated that SLNs delayed the abrupt growth of keratinocytes, while in vivo mouse tail model showed that SLNs gel significantly decreased the epidermal thickness and increased melanocyte count in comparison to commercial Daivobet® ointment.Conclusions: The developed SLNs gel is expected to be potential strategies for treatment of psoriasis and other topical diseases.

Application of the Long Tail Economy to the Online News Market: Examining Predictors of Market Performance

The online news market worldwide has met several challenges, one of which is the lack of sustainable business models. The long tail is a concept defined by Chris Anderson to describe a business model used by the majority of Internet firms and ecommerce stores. Is the long tail model crucial to the news media's competitive market capacity today? The study integrates relevant economic concepts of production costs, distribution costs, search costs, and market performance to construct a long tail economy for online news. Using survey, third-party traffic metrics, and content analysis, this study found that the traffic performance of online news sites was significantly impacted by long tail forces, but the impact had not transferred to the news sites' financial performance. The synthesis provides rich explanations of how the long tail economy can be applied to online news to reveal the forces that both drive and constrain its performance.

Anti-Psoriatic Activity of Flavonoids from the Bark of Givotia rottleriformis Griff. Ex Wight.

Givotia rottleriformis has been used in the indigenous systems of medicine for the treatment of inflammatory diseases like rheumatism and psoriasis. In order to evaluate this information, antipsoriatic activity of three flavonoids isolated from the ethanol extract of the bark of Givotia rottleriformis were investigated using in-vitro and in-vivo model, namely Rutin (I), Luteolin-7-O-β-D-Glucuronide (II) and Kaempferol 3-O-[2-O-(6-O-feruloyl)-β-D-glucopyranosyl]-β-D-galactopyranoside (III). The extract was standardized by HPLC using chemical markers. In vitro antiproliferant assay of the ethanol extract and isolated flavonoids were done on HaCaT cell lines. Mouse tail test was used for the evaluation of antipsoriatic activity of ethanol extract (100, 200 and 400 mg/kg b.w.) and bioactive flavonoids (50 mg/kg b.w.) in Swiss albino mice. In the HPLC analysis, 4 flavonoids were identified by comparison with retention time of standard marker viz., Rutin, Quercetin, Kaempferol and Luteolin. Maximum antiproliferant activity was shown by isolated flavonoids II and III (56.50±12.84μg/ml and 76.50±8.60μg/ml). In mouse tail model, a significant reduction in epidermal thickness with respect to control was observed in groups treated with isolated flavonoids II, III and significant orthokeratosis was observed in groups treated with ethanol extract (200 and 400 mg/kg) and isolated flavonoids II, III.

Modelling the thermal inactivation of five Campylobacteraceae species

Abstract This study investigated the thermal inactivation of five Campylobacteraceae species (Campylobacter coli, Campylobacter helveticus, Campylobacter concisus, Campylobacter fetus subsp. fetus and Arcobacter butzleri) at 55 and 60 °C using an immersed coil heating apparatus. The applicability of nine different models, including log linear and Weibull type models, some of which accounted for shoulders and tailing populations at the start or end of the heat treatment, was assessed to describe the thermal inactivation of each species. The Weibull model with tailing effect provided a good fit with low RMSE value (0.07–0.27), AICc (−88.12 to −6.82) and high R2 values (0.97–0.99) depending on the temperature and the species. The Weibull + tail model showed a significantly high D value for Arcobacter butzerli (180.2 s) at 55 °C and a low D value for C. helveticus (23.9 s) at 60 °C, with a high degree of variability in thermal tolerance noted across the species. Moreover, the Weibull + tail model also indicated high thermal sensitivity for C. fetus subsp. fetus at both temperatures investigated. This study highlights the value of assessing various inactivation models to describe the D value to get the model which best describes the survival data. These model predictions enhance knowledge about the survival characteristics and behaviour of fastidious Campylobacteraceae in the food chain.

Piracy and Movie Revenues: A Critical Review of a Tale of the Long Tail

A recent study on piracy entitled Piracy and Movie Revenues: Evidence from Megaupload: A Tale of the Long Tail? serves up the counter-intuitive claim that piracy may increase box office sales for some films. To reach this conclusion, Tale of the Long Tail uses as an "experiment" the January 2012 shutdown of what was likely the single largest online distributor of pirated content — the file sharing website Megaupload. Using data on weekend box office revenues for thousands of films shown in about fifty countries, the authors split this data into pre- and post-shutdown periods, and then apply econometric methods to test for a difference between the two samples, attributed any observed change to the shutdown. Upon close inspection the "piracy helps box office sales" result if found to be an artifact of a poorly designed statistical model, which is, in part, a consequence of the study's authors ignoring the basic economics of the box office. The defect in the Tale of the Long Tail's model is revealed in the dubious implication of that model that a "blockbuster" movie (as the authors define it) will earn no more revenue than a "small movie" and far less revenue than a "mid size" movie. In fact, according to the analysis in Tale of the Long Tail, what the authors define to be a "blockbuster" movie makes only one-fourth (1/4) of the revenues of mid-sized movies. The bizarre result about the benefits of piracy is based upon this dubious implication of the statistical model. In this PERSPECTIVE, I detail this problem with Tale of the Long Tail, and outline a few other defects. There are far too many problems with the study's empirical approach to cover them all in detail, including the fundamental question regarding whether the general "before" and "after" approach can identify the effect of piracy generally, and whether the authors have estimated a model capable of capturing the effect. A thorough analysis of the study is unnecessary since the study's central (and most controversial) finding is easily dismissed.

Reinvestigating the Uncovered Interest Rate Parity Puzzle Via Analysis of Multivariate Tail Dependence in Currency Carry Trades

The currency carry trade is the investment strategy that involves selling low interest rate currencies in order to purchase higher interest rate currencies, thus profiting from the interest rate differentials. This is a well known financial puzzle to explain, since assuming foreign exchange risk is uninhibited and the markets have rational risk-neutral investors, then one would not expect profits from such strategies. That is uncovered interest rate parity (UIP), the parity condition in which exposure to foreign exchange risk, with unanticipated changes in exchange rates, should result in an outcome that changes in the exchange rate should offset the potential to profit from the interest rate differentials. Given foreign exchange market equilibrium, the interest rate parity condition implies that the expected return on domestic assets will equal the exchange rate-adjusted expected return on foreign currency assets. However, it has been shown empirically, that investors can actually earn profits by borrowing in a country with a lower interest rate, exchanging for foreign currency, and investing in a foreign country with a higher interest rate, whilst allowing for any losses (or gains) from exchanging back to their domestic currency at maturity. Therefore trading strategies that aim to exploit the interest rate differentials can be profitable on average. The intention of this paper is therefore to reinterpret the currency carry trade puzzle in light of heavy tailed marginal models coupled with multivariate tail dependence features. We analyse the returns of currency carry trade portfolios adjusting for tail dependence risk. To achieve this analysis of the multivariate extreme tail dependence we develop several parametric models and perform detailed model comparison. It is thus demonstrated that tail dependencies among specific sets of currencies provide other justifications to the carry trade excess return and also allow us to detect construction and unwinding periods of such carry portfolios.

Notochordal cell disappearance and modes of apoptotic cell death in a rat tail static compression-induced disc degeneration model

IntroductionThe intervertebral disc has a complex structure originating developmentally from both the mesenchyme and notochord. Notochordal cells disappear during adolescence, which is also when human discs begin to show degenerative signs. During degeneration later in life, disc cells decline because of apoptosis. Although many animal models have been developed to simulate human disc degeneration, few studies have explored the long-term changes in cell population and phenotype. Our objective was to elucidate the time-dependent notochordal cell disappearance and apoptotic cell death in a rat tail static compression-induced disc degeneration model.MethodsTwenty-four 12-week-old male Sprague–Dawley rat tails were instrumented with an Ilizarov-type device and loaded statically at 1.3 MPa for up to 56 days. Loaded and distal-unloaded discs were harvested. Changes in cell number and phenotype were assessed with histomorphology and immunofluorescence. Apoptosis involvement was determined with terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and immunohistochemistry.ResultsThe number of disc nucleus pulposus and annulus fibrosus cells decreased with the loading period; particularly, the decrease was notable at day 7 in larger, vacuolated, cytokeratin-8- and galectin-3-co-positive cells, indicating notochordal origin. Subsequently, the proportion of cells positive for TUNEL and cleaved caspase-3, markers of apoptosis induction, increased from day 7 through day 56. Although the percentage of cells immunopositive for cleaved caspase-8, a marker of apoptosis initiation through the death-receptor pathway, increased only at day 7, the percentage of cells immunopositive for cleaved caspase-9 and p53-regulated apoptosis-inducing protein 1 (p53AIP1), markers of apoptosis initiation through the p53-mediated mitochondrial pathway, increased from day 7 through day 56. The percentage of cells immunopositive for B-cell lymphoma 2 (Bcl-2) and silent mating type information regulation 2 homolog 1 (SIRT1), antiapoptotic proteins, decreased consistently with compression.ConclusionsThis rat tail model mimics notochordal cell disappearance and apoptotic cell death in human disc aging and degeneration. Sustained static compression induces transient activation of apoptosis through the death-receptor pathway and persistent activation of apoptosis through the p53-mediated mitochondrial pathway in disc cells. The increased proapoptotic and decreased antiapoptotic proteins observed at all time points signify static compression-induced disc cell death and degeneration.

Effects of enoxaparin and rivaroxaban on tissue survival in skin degloving injury: an experimental study.

The aim of this study was to evaluate the effects of the antithrombotic agents enoxaparin and rivaroxaban on tissue survival following skin degloving injury in an experimental rat tail model. The study included 24 rats divided into three equal groups of 8; the enoxaparin group (Group 1), the rivaroxaban group (Group 2) and the saline control group (Group 3). A degloving injury was created by making a circular incision 5 cm distal to the base of the tail; manual traction was applied to the tail skin distal to the incision. After 15 minutes, the ends of the incision were sutured back in place. Antithrombotic agents were administered immediately after suturing and repeated once a day for 15 days. At the end of Day 15, the experiment was terminated. Gross morphological tissue survival and histopathology were evaluated. Histopathological examination of the enoxaparin and rivaroxaban groups revealed that the skin was mostly normal or intact with minimal inflammation. The mean length of necrotic area was significantly higher in the saline group compared to the enoxaparin and rivaroxaban groups (p<0.05). No statistically significant differences were noted between the rivaroxaban and enoxaparin groups (p=0.451). The mean extent of skin necrosis was significantly higher in the control group than the study groups (p<0.05), while there was no significant difference in the length of necrotic area between Group 1 and 2 (p=0.722). Rivaroxaban and enoxaparin improved tissue survival in skin degloving injuries in terms of gross morphological and histopathological findings in a rat tail model.

Analysis and interpretation of 15 quarters ofKeplerdata of the disintegrating planet KIC 12557548 b

The Kepler object KIC 12557548 shows irregular eclipsing behaviour with a constant 15.685 hr period, but strongly varying transit depth. In this paper we fit individual eclipses, in addition to fitting binned light curves, to learn more about the process underlying the eclipse depth variation. Additionally, we put forward observational constraints that any model of this planet-star system will have to match. We find two quiescent spells of ~30 orbital periods each where the transit depth is <0.1%, followed by relatively deep transits. Additionally, we find periods of on-off behaviour where >0.5% deep transits are followed by apparently no transit at all. Apart from these isolated events we find neither significant correlation between consecutive transit depths nor a correlation between transit depth and stellar intensity. We find a three-sigma upper limit for the secondary eclipse of 4.9*10^-5, consistent with a planet candidate with a radius of less than 4600 km. Using the short cadence data we find that a 1-D exponential dust tail model is insufficient to explain the data. We improved our model to a 2-D, two-component dust model with an opaque core and an exponential tail. Using this model we fit individual eclipses observed in short cadence mode. We find an improved fit of the data, quantifying earlier suggestions by Budaj (2013) of the necessity of at least two components. We find that deep transits have most absorption in the tail, and not in a disk-shaped, opaque coma, but the transit depth and the total absorption show no correlation with the tail length.

Cell transplantation therapy for a rat model of secondary lymphedema

BackgroundAlthough lymphedema is a progressive and lifelong condition, substantial advances in therapeutic intervention are limited. The development of a novel therapy for lymphedema is urgent for those patients suffering from it. The aim of this study was to investigate the usefulness of a new cell transplantation therapy in the rat tail model of secondary lymphedema. Materials and methodsWe prepared two cell sources, human dermal microvascular endothelial cells (HDMECs) and lymphatic endothelial cells (LECs), which were collected from the resected normal dermis of patients with breast cancer. After the animal model of secondary lymphedema of the nude rats' tails was established, phosphate-buffered saline, purified LECs, or unpurified HDMECs were injected in the rats' tails five times for more than 14 d. The evaluations were performed by measuring the circumference, fluorescence lymphography, and histologic analysis of the rats' tails between each group. ResultsThe isolated cells by the simple immunomagnetic sorting from HDMECs were positive for a pan-endothelial marker (CD31) and lymphatic-specific markers (podoplanin, lymphatic vessel endothelial hyaluronan receptor-1 [LYVE-1], and prospero homebox 1 [Prox-1]), and were considered to be LECs. In the cell transplantation group, which was injected with human LECs, the circumference, lymphatic flow, and thickness of the skin of the rat tail became thinner than the groups injected with unpurified HDMECs or phosphate-buffered saline. Immunohistochemistry of the rat tails showed that the number of own lymphatic vessels was increased in the purified LEC transplantation group compared with the other groups. Furthermore, in the LEC transplantation group, some vessels were immunopositive for human-podoplanin or -LYVE-1 and the areas adjacent to the vessels were rat-podoplanin or -LYVE-1 immunopositive. ConclusionsOur findings indicate that cell transplantation therapy using human LECs improved the secondary lymphedema in the nude rat tail. This therapeutic strategy may merit clinical investigation in patients with lymphedema.

What’s in a Niche? Exploring the Business Model of Online Journalism

There has been much discussion about a shift from general news towards a marketplace of niche. We have examined the business models of 69 journalistic online-only startups in 2011–12 in ten countries operating a sustainable niche. We correlate our findings against Chris Anderson’s long-tail Internet model to explore if it can explain the marketplace of niche journalism. We find that the long tail model goes some way to explain the business model of journalistic content creation. However, it does not allow for the complexities around niche that generate revenues around platforms, selling technology or information on a business-tobusiness basis.

The open long tail model between new culture and digital technology

Purpose of the study . The aim of this paper is to describe an emerging business model that comes from the digitalization of the world of making tangible objects. Methodology . The creation of niche products , their production and sales in an open business model is analyzed through the literature review of both models and sustained by the analysis of practice cases. Findings . This new business model , defined by the authors as the open long tail model, includes the features of both the open business model and the long tail model because it sustains the collaborative trend of the web generation and creates a large number of niche, physical things rather that “just pixels on screens”. Research limits . Given its focus on the empirical evidence from the diffusion of new digital and flexible technologies , our analysis has identified a new trend in the manufacturing industry business model that seems to have a positive effect on the organization as well as the costumer. Practical implications . The future of this emerging business model looks promising thanks to its democratization of creativity and manufacturing trajectory and its capability to create more revenue for anyone who wants to undertake this venture. Novelty of the paper . This new stream of creativity democratization and innovation is possible thanks to the open long tail model based the new user that wants to make objects, the emergence of digital tools for design and production, the collaboration between actors.

Mathematical quantification of microbial inactivation of Escherichia coli O157:H7 and Salmonella spp. on stainless steel surfaces soiled with different vegetable juice substrates

Microbial survival on inert surfaces should be considered as an important factor to understand and quantify bacterial transfer to foods (i.e. cross contamination). The present work studied the survival of Escherichia coli O157:H7 and Salmonella spp. on stainless steel surfaces with different soiling substrates based on leafy vegetable juices. Furthermore, predictive models were proposed to describe survival patterns shown by both pathogens in the different substrates. E. coli O157:H7 and Salmonella spp. could be recovered until 192 and 168h, respectively from surfaces soiled with chard, red cabbage, iceberg lettuce and romaine lettuce. However, in spinach and parsley juice substrates, microorganisms were not detected after 48h. This survival 10/5/2013; Time:1:31:57time was much lower than that obtained in saline solution (120h), used to simulate clean surfaces. The reduction rates observed in a period of time of 2 and 24h for E. coli O157:H7 depended on the type of substrate and ranged 1.03–2.27 and 0.14–0.27logcfu/cm2h, respectively. For Salmonella spp. results showed slightly lower drops, with 0.89–1.62 and 0.15–0.25logcfu/cm2h, for 2 and 24h, respectively. The Weibull model and Weibull+tail model seemed to be the most suitable mathematical functions describing survival of both microorganisms in the different substrates (adj-R2=0.94–0.99). Experiments were developed simulating environmental conditions given in fresh-cut vegetable factories. Therefore, results and models generated in this study could be applied in quantitative risk assessment studies to obtain a more accurate representation of cross contamination, in addition to enabling the assessment of control strategies of both pathogens in the fresh-cut vegetable industry.

UV-C light inactivation and modeling kinetics of Alicyclobacillus acidoterrestris spores in white grape and apple juices

In the present study, the effect of short wave ultraviolet light (UV-C) on the inactivation of Alicyclobacillus acidoterrestris DSM 3922 spores in commercial pasteurized white grape and apple juices was investigated. The inactivation of A. acidoterrestris spores in juices was examined by evaluating the effects of UV light intensity (1.31, 0.71 and 0.38mW/cm2) and exposure time (0, 3, 5, 7, 10, 12 and 15min) at constant depth (0.15cm). The best reduction (5.5-log) was achieved in grape juice when the UV intensity was 1.31mW/cm2. The maximum inactivation was approximately 2-log CFU/mL in apple juice under the same conditions. The results showed that first-order kinetics were not suitable for the estimation of spore inactivation in grape juice treated with UV-light. Since tailing was observed in the survival curves, the log-linear plus tail and Weibull models were compared. The results showed that the log-linear plus tail model was satisfactorily fitted to estimate the reductions. As a non-thermal technology, UV-C treatment could be an alternative to thermal treatment for grape juices or combined with other preservation methods for the pasteurization of apple juice.

Development and wind tunnel evaluation of a shape memory alloy based trim tab actuator for a civil aircraft

This paper presents the development and wind tunnel evaluation of a shape memory alloy (SMA) based smart trim tab for a typical two seater civil aircraft. The SMA actuator was housed in the port side of the elevator for the purpose of actuating the trim tab. Wind tunnel tests were conducted on a full scale horizontal tail model with elevator and trim tab at free stream speeds of 25, 35 and 45 m s−1, and also for a number of deflections of the elevator (30° up, 0° neutral and 25° down) and trim tab (11° and 21° up and 15° and 31° down). To measure the hinge moment experienced by the trim tab under various test conditions, two miniaturized balances were designed and fabricated. A gain scheduled proportional integral (GSPI) controller was developed to control the SMA actuated smart trim tab. It was confirmed during the tests that the trim tab could be controlled at the desired position against the aerodynamic loads acting on it for the various test conditions.

Nano-lipoidal carriers of tretinoin with enhanced percutaneous absorption, photostability, biocompatibility and anti-psoriatic activity

Tretinoin (TRE) is a widely used retinoid for the topical treatment of acne, psoriasis, skin cancer and photoaging. Despite unmatchable efficacy, it is associated with several vexatious side effects like marked skin erythema, peeling and irritation, eventually leading to poor patient compliance. Its photo-instability and high lipophilicity also pose challenges in the development of a suitable topical product. The present study, therefore, aims to develop biocompatible lipid-based nanocarriers of TRE to improve its skin delivery, photostability, biocompatibility and pharmacodynamic efficacy. The TRE-loaded liposomes, ethosomes, solid lipid nanoparticles (SLNs) and nanostructured lipidic carriers (NLCs) were prepared and characterized for micromeritics, surface charge, percent drug efficiency and morphology. Bioadhesive hydrogels of the developed systems were also evaluated for rheological characterization, photostability, ex vivo skin permeation and retention employing porcine skin, and anti-psoriatic activity in mouse tail model. Nanoparticulate carriers (SLNs, NLCs) offered enhanced photostability, skin transport and anti-psoriatic activity vis-à-vis the vesicular carriers (liposomes, ethosomes) and the marketed product. However, all the developed nanocarriers were found to be more biocompatible and effective than the marketed product. These encouraging findings can guide in proper selection of topical carriers among diversity of such available carriers systems.