A trajectory generation and system characterization model for cislunar low-thrust spacecraft. Volume 2: Technical manual

The documentation of the Trajectory Generation and System Characterization Model for the Cislunar Low-Thrust Spacecraft is presented in Technical and User's Manuals. The system characteristics and trajectories of low thrust nuclear electric propulsion spacecraft can be generated through the use of multiple system technology models coupled with a high fidelity trajectory generation routine. The Earth to Moon trajectories utilize near Earth orbital plane alignment, midcourse control dependent upon the spacecraft's Jacobian constant, and capture to target orbit utilizing velocity matching algorithms. The trajectory generation is performed in a perturbed two-body equinoctial formulation and the restricted three-body formulation. A single control is determined by the user for the interactive midcourse portion of the trajectory. The full spacecraft system characteristics and trajectory are provided as output

Formulation and evaluation of floating mucoadhesive alginate beads for targetingHelicobacter pylori

Objectives: There are various obstacles in the eradication of Helicobacter.pylori (H. pylori) infections, including low antibiotic levels and poor accessibility of the drug at the site of the infection. This study describes the preparation and characterisation of novel floating-mucoadhesive alginate beads loaded with clarithromycin (CMN) for delivery to the gastric mucosa to improve the eradication of this micro-organism. Methods: Calcium alginate beads were prepared by ionotropic gelation. The formulation was modified through addition of oil and coating with chitosan in order to improve floating, mucoadhesion and modify drug release. Key findings: SEM confirmed the sphericity of the beads with X-ray microtomography (XμMT) showing the 3D structure of the beads with the layered internal structure of the bead and the even distribution of the drug within the bead. This formulation combined two gastro-retentive strategies and these formulations produced excellent in vitro floating, mucoadhesive and drug release characteristics. Enhanced stability of the beads in phosphate buffer raises a potential for the modified formulations to be targeted to regions of higher pH within the gastrointestinal tract with a higher pH. Drug release from these beads was sustained through an unstirred mucin layer simulating in vivo conditions under which the H. pylori resides in the gastric mucosa. Conclusions: This novel formulation will ensure retention for a longer period in the stomach than conventional formulations and control drug release, ensuring high local drug concentrations, leading to improved eradication of the bacteria

Razvoj i optimizacija sustava za isporuku metoprolol sukcinata sa zadržavanjem u želucu

Metoprolol succinate (MS) gastroretentive (GR) controlled release system was formulated to increase gastric residence time leading to improved drug bioavailability. Box-Behnken model was followed using novel combinations of sodium alginate (SA), sodium carboxymethylcellulose (NaCMC), magnesium alumino metasilicate (MAS) as independent variables. Floating lag time (Flag), t25, t50, t75, diffusion exponent as dependent variables revealed that the amount of SA, NaCMC and MAS have a significant effect (p < 0.05) on t25, t50, t75 and Flag. MSGR tablets were prepared and evaluated for mass, thickness, hardness, friability, drug content and floating property. Tablets were studied for dissolution for 24 h and exhibited controlled release of MS with floating for 16 h. The release profile of the optimized batch MS01 fitted first-order kinetics (R2 = 0.9868, n = 0.543), indicating non-Fickian diffusion or anomalous transport by diffusion and swelling.U radu je opisan razvoj sustava za isporuku metoprolol sukcinata (MS) s kontroliranim oslobađanjem i produljenim vremenom zadržavanja u želucu (GR), u svrhu poboljšanja bioraspoloživosti. Primijenjen je Box-Behnkenov model, a kao zavisne varijable izabrane su nove kombinacije natrijevog alginata (SA), natrijeve soli karboksimetilceluloze (NaCMC) i magnezijevog aluminometasilikata (MAS). Vrijeme plutanja (Flag), t25, t50, t75 i difuzijski eksponent kao zavisne varijable otkrili su da količina SA, NaCMC i MAS ima značajan učinak (p < 0,05) na t25, t50, t75 i Flag. Pripravljenim tabletama određena je masa, debljina, tvrdoća, lomljivost, sadržaj ljekovite tvari i sposobnost plutanja. Oslobađanje MS praćeno je 24 h. Rezultati pokazuju da je oslobađanje kontrolirano, a vrijeme plutanja 16 h. Oslobađanje iz optimiranog pripravka MS01 slijedi kinetiku prvog reda (R2 = 0,9868, n = 0,543), što ukazuje na difuziju koja ne slijedi Fickov zakon već anomalni transport difuzijom i bubrenjem

Asher Lev at the Israel Museum: Stereotyping art and craft

Jesper Svartvik and Jakob Wirén (Eds.), Religious stereotyping and interreligious relations. New York: Palgrave Macmillan, 2013, reproduced with permission of Palgrave Macmillan. This extract is taken from the author's original manuscript and has not been edited. The definitive, published version of record is available here: http://www.palgrave.com/page/detail/religious-stereotyping-and-interreligious-relations-jesper-svartvik/?K=9781137344601 and http://www.palgraveconnect.com/pc/doifinder/10.1057/978113734267

Scientific Exploration of Near-Earth Objects via the Crew Exploration Vehicle

The concept of a crewed mission to a Near-Earth Object (NEO) has been analyzed in depth in 1989 as part of the Space Exploration Initiative. Since that time two other studies have investigated the possibility of sending similar missions to NEOs. A more recent study has been sponsored by the Advanced Programs Office within NASA's Constellation Program. This study team has representatives from across NASA and is currently examining the feasibility of sending a Crew Exploration Vehicle (CEV) to a near-Earth object (NEO). The ideal mission profile would involve a crew of 2 or 3 astronauts on a 90 to 120 day flight, which would include a 7 to 14 day stay for proximity operations at the target NEO. One of the significant advantages of this type of mission is that it strengthens and validates the foundational infrastructure for the Vision for Space Exploration (VSE) and Exploration Systems Architecture Study (ESAS) in the run up to the lunar sorties at the end of the next decade (approx.2020). Sending a human expedition to a NEO, within the context of the VSE and ESAS, demonstrates the broad utility of the Constellation Program s Orion (CEV) crew capsule and Ares (CLV) launch systems. This mission would be the first human expedition to an interplanetary body outside of the cislunar system. Also, it will help NASA regain crucial operational experience conducting human exploration missions outside of low Earth orbit, which humanity has not attempted in nearly 40 years

Evaluacija svojstava vezanja sluzi sjemenki biljke Plantago psyllium

Mucilage extracted from Plantago psyllium seeds was evaluated for inertness and safety parameters. The suitability of psyllium mucilage for a pharmaceutical binder was assessed in paracetamol tablets. Properties of the granules prepared using different concentrations of psyllium mucilage was compared with PVP and tragacanth. Psyllium mucilage at 5 % (m⁄m) level was found to be comparable with 3 % (m⁄m) of PVP. Investigated paracetamol tablets indicated that psyllium mucilage can retard the drug release.U radu je ispitivana neškodljivost i sigurnost uporabe sluzi ekstrahirane iz sjemenki biljke Plantago psyllium. Primjenjivost te sluzi kao veziva u farmaceutskim pripravcima ispitana je na tabletama paracetamola. Granule pripravljene s različitim koncentracijama sluzi uspoređene su s granulama s PVP-om i tragakantom. Sluz s udjelom 5 % (m/m) usporediva je s otopinom PVP-a masenog udjela 3 %. Pripravljene tablete paracetamola ukazuju na to da ispitivana sluz može usporiti oslobađanje lijeka

Termoreverzibilni mukoadhezivni in situ hidrogel za oftalmičku primjenu: dizajniranje i optimizacija koristeći kombinaciju polimera

The purpose of the study was to develop an optimized thermoreversible in situ gelling ophthalmic drug delivery system based on Pluronic F 127, containing moxifloxacin hydrochloride as a model drug. A 32 full factorial design was employed with two polymers Pluronic F 68 and Gelrite as independent variables used in combination with Pluronic F 127. Gelation temperature, gel strength, bioadhesion force, viscosity and in vitro drug release after 1 and 10 h were selected as dependent variables. Pluronic F 68 loading with Pluronic F 127 was found to have a significant effect on gelation temperature of the formulation and to be of importance for gel formation at temperatures 3336 ºC. Gelrite loading showed a positive effect on bioadhesion force and gel strength and was also found helpful in controling the release rate of the drug. The quadratic mathematical model developed is applicable to predicting formulations with desired gelation temperature, gel strength, bioadhesion force and drug release properties.Cilj rada bio je razvoj i optimizacija termoreverzibilnog sustava za isporuku lijekova koji gelira in situ. Sustav je napravljen na bazi Pluronic F 127, a sadrži moksifloksacin hidroklorid kao modelni lijek. U radu je primjenjeno 32 potpuno faktorijsko dizajniranje s dva polimera, Pluronic F 68 i Gelrite kao nezavisnim varijablama koji su kombinirani s Pluronic F 127. Kao zavisne varijable odabrane su temperatura geliranja, čvrstoća gela, jačina bioadhezije, viskoznost i in vitro oslobađanje lijeka nakon 1 i 10 h. Pronađeno je da Pluronic F 68 u kombinaciji s Pluronic F 127 ima značajan učinak na temperaturu geliranja u rasponu od 33 do 36 C. S druge strane, Gelrite ima povoljan učinak na jačinu bioadhezije, čvrstoću gela i oslobađanje lijeka. Razvijen je kvadratni matematički model pomoću kojeg se može predvidjeti temperatura geliranja, čvrstoća gela, jačina bioadhezije i oslobađanje ljekovite tvari