miniaturization
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With the current transformation of the pharmaceutical industry towards continuous manufacturing, there is an inherent need to embrace this concept already during the early stages of drug formulation. Therefore, this research paper investigated the feasibility of using miniaturized forced feeders on a high-speed rotary tablet press with the intention of downscaling the tableting process. Forced feeders with a reduced volume (up to 46% compared to the conventional two-compartment forced feeder) were designed by either sealing one compartment (i.e. R&D1) or lowering of the compartment height (i.e. R&D2). These feed frame designs were thoroughly analysed in combination with two paddle types over a wide range of process-settings (i.e. tableting speed, paddle speed, direction of paddle rotation, overfill-level). A poorly flowing model powder (i.e. MCC 101) was deliberately selected as challenging formulation. Empirical modelling of feed frame R&D1 revealed a positive impact on the die-filling variability when the radial curved cuboid paddles rotated in counterclockwise direction at high paddle speed. Moreover, a strong resemblance between the R&D2 feed frame and the conventional forced feeder was observed during multivariate data analysis, indicating that this miniaturized type could be used during downscaling studies of the conventional tableting process. The potential of this forced feeder was acknowledged by the similar trends in die-filling variability with respect to varying process settings, when a design-of-experiments (DOE) was performing including feed frame type as a qualitative factor. Overall, it was concluded that both types of miniaturized forced feeders can be used on a high-speed rotary tablet press when lower material consumption rates are desired while the R&D2 feed frame bears the highest predictability regarding the die-filling uniformity in the conventional larger two-compartment forced feeder.
- MeSH
- celulosa MeSH
- farmaceutická technologie metody MeSH
- miniaturizace MeSH
- pomocné látky MeSH
- tablety * MeSH
- Publikační typ
- časopisecké články MeSH
Miniaturizace je jedním z velkých témat současnosti a v chemii se také uplatňuje. Z chemických reakcí ve větších měřítkách, v baňkách, se přechází na miniaturizované systémy mikroreaktorů. Postupným vývojem byly optimalizovány materiály i techniky pro práci v mikroměřítku. Mnohé studie se zabývají rozborem dokonce jednotlivých molekul, často se jedná o makromolekuly typu DNA, nebo proteinu. Je možné vytvářet reaktory s objemem attolitrů. Některé experimenty slibují do budoucna užitečnou aplikaci v medicíně, ale i dalších oborech.
Today, miniaturization is one of the top topics and chemistry undergoes it as well. Chemical reactions were usually performed in flasks but at the present time, there are many endeavours to miniaturize them to microreactor systems. Used methods and materials are still being optimised to be able to work in this micro and nano-scale volume. There are many experiments studying even single molecules (often macromolecules like DNA or proteins). It is possible to create reactors even of attoliter volume. Therefore applications in medicine and other disciplines can be expected in the future.
The nondestructive identification of both inorganic and organic compounds without the need for chemical or mechanical sample preparation is an advantage of the Raman spectroscopic analytical technique when applied in situ using miniaturized equipment for the geosciences. This is critically assessed here for several real life geoscientific scenarios in which several groups of minerals were analyzed with emphasis on evaporites, carbonates, and selected types of dark minerals and weak Raman scatterers. The role of individual analytical instrumental parameters such as focal plane precision, exposure time, and ambient light conditions that can affect the acquisition and interpretation of spectroscopic data from these specimens in field conditions was also evaluated.
We tested the potential of a miniaturized Raman spectrometer for use in field detection of snow algae pigments. A miniature Raman spectrometer, equipped with an excitation laser at 532 nm, allowed for the detection of carotenoids in cells of Chloromonas nivalis and Chlamydomonas nivalis at different stages of their life cycle. Astaxanthin, the major photoprotective pigment, was detected in algal blooms originating in snows at two alpine European sites that differed in altitude (Krkonoše Mts., Czech Republic, 1502 m a.s.l., and Ötztal Alps, Austria, 2790 m a.s.l.). Comparison is made with a common microalga exclusively producing astaxanthin (Haematococcus pluvialis). The handheld Raman spectrometer is a useful tool for fast and direct field estimations of the presence of carotenoids (mainly astaxanthin) within blooms of snow algae. Application of miniature Raman instruments as well as flight prototypes in areas where microbes are surviving under extreme conditions is an important stage in preparation for successful deployment of this kind of instrumentation in the framework of forthcoming astrobiological missions to Mars. Key Words: Snow algae-Chloromonas nivalis-Chlamydomonas nivalis-On-site field detection-Raman spectroscopy-Astaxanthin. Astrobiology 16, 913-924.
- MeSH
- Chlamydomonas chemie MeSH
- Chlorophyta chemie MeSH
- karotenoidy analýza MeSH
- ledový příkrov MeSH
- miniaturizace přístrojové vybavení MeSH
- Ramanova spektroskopie přístrojové vybavení MeSH
- sníh mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
A miniaturized extraction/preconcentration method based on an aqueous biphasic system (μ-ABS) was developed with reagents commonly used as food additives: cholinium chloride (ChCl) as main extraction phase, K2HPO4 as salting-out agent, and water as the main component (being the sample for analyses). With the aim of obtaining high enrichment factors, miniaturization, and adequate analytical performance, a point in the biphasic region with the lowest amount of ChCl was selected, corresponding to 1.55% (w/w) of ChCl, 59.5% (w/w) of K2HPO4, and 38.95% (w/w) of water. The green μ-ABS (attending to its main elements and performance mode) was used in combination with high-performance liquid chromatography with diode-array detection (HPLC-DAD) for the determination of 9 personal care products in wastewater samples. The μ-ABS-HPLC-DAD method showed high enrichment factors (up to 100), and quantitative extraction efficiencies for those compounds containing OH groups in their structure, which can undergo hydrogen bonding with ChCl. Thus, limits of quantification down to 0.8 µg·L-1 and extraction efficiencies between 66.4 and 108% (concentration levels of 1.3 and 13 µg·L-1) were reached for the group of parabens and the UV-filter benzophenone-3. The method is characterized by the use of non-harmful reagents and the absence of organic solvents in the entire sample preparation procedure, while being simple, low-cost, easily compatible with HPLC, and highly efficient.
- MeSH
- chemické látky znečišťující vodu analýza MeSH
- chloridy analýza MeSH
- fosfáty analýza MeSH
- kosmetické přípravky analýza MeSH
- miniaturizace * MeSH
- odpadní voda chemie MeSH
- reprodukovatelnost výsledků MeSH
- rozpouštědla chemie MeSH
- voda analýza MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
Corneal allograft rejection is frequently studied in small rodent or rabbit models. To study mechanisms of rejection in a model that more closely mimics transplantation in humans, we performed orthotopic corneal transplantation in the miniature pig using a 7-mm diameter donor graft. Four groups of recipients were studied: 1) untreated naive, 2) untreated vascularized (high risk), 3) high-risk grafts treated by topical application of prednisolone, or 4) high-risk grafts treated with a combined systemic immunosuppression regime of oral prednisone, cyclosporine A, and mycophenolate mofetil. Both the clinical features and histological assessment of corneal graft rejection showed close similarities to graft rejection in humans. Interestingly, preliminary results indicated that topical steroid treatment was superior to systemic immunosuppression in significantly promoting graft survival. Thus, corneal transplantation in the pig represents an animal model most closely resembling corneal grafting in humans, and offers possibilities for testing various clinically applicable immunosuppressive treatments.
- MeSH
- financování organizované MeSH
- imunosupresiva terapeutické užití MeSH
- kombinovaná farmakoterapie MeSH
- miniaturní prasata MeSH
- modely u zvířat MeSH
- prasata MeSH
- přežívání štěpu účinky léků MeSH
- rejekce štěpu prevence a kontrola MeSH
- transplantace rohovky imunologie metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
