scholarly journals Luminescent Composites on the Base of Microcrystalline Cellulose: Synthesis, Fabrication and Properties

2018 ◽  
Author(s):  
S.G. Nedilko ◽  
S. Hamamda ◽  
M.S. Nedielko ◽  
O.M. Alekseev ◽  
Yu.E. Grabovskyi ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Cellulose Synthesis

A promising energetic biopolymer based on azide-functionalized microcrystalline cellulose: Synthesis and characterization

2020 ◽  
Vol 249 ◽  
pp. 116820
Author(s):  
Ahmed Fouzi Tarchoun ◽  
Djalal Trache ◽  
Thomas M. Klapötke ◽  
Burkhard Krumm ◽  
Kamel Khimeche ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Synthesis And Characterization ◽  
Cellulose Synthesis

scholarly journals Low And Highly Substituted Carboxymethyl Cellulose Synthesis From Powdered And Microcrystalline Cellulose

2020 ◽  
Vol 02 (10) ◽  
pp. 83-96
Author(s):  
Yuldoshov Sherzod Abdullaevich ◽  
◽  
Sarymsakov Abdushkur Abdukhalilovich ◽  
Keyword(s):  
Microcrystalline Cellulose ◽  
Carboxymethyl Cellulose ◽  
Degree Of Substitution ◽  
Water Soluble ◽  
Cellulose Synthesis ◽  
One Stage ◽  
Powder Cellulose ◽  
Substitution Degree ◽  
High Degree

The conditions for low and highly substituted water-soluble carboxymethyl cellulose synthesis based on microcrystalline and powder cellulose by the suspension method have been investigated. Accordingly, it was obtained CMC water-soluble samples with 0.38-0.40 substitution degree based on microcrystalline and powder cellulose. And at one stage, there were obtained CMC samples with a high degree of substitution (1.4) by carboxymethylation so called polyanionic cellulose.

Single molecule optical diffraction: A tool for understanding the structure of triple stranded left-hand helical cellulose

1989 ◽  
Vol 47 ◽  
pp. 1024-1025
Author(s):  
George C. Ruben ◽  
William Krakow
Keyword(s):  
Single Molecule ◽  
Helical Structure ◽  
Optical Diffraction ◽  
Maximum Diameter ◽  
Primary Cell Wall ◽  
Cellulose Synthesis ◽  
Left Hand ◽  
Left Handed ◽  
Freeze Dried ◽  
Diffraction Patterns

Tobacco primary cell wall and normal bacterial Acetobacter xylinum cellulose formation produced a 36.8±3Å triple-stranded left-hand helical microfibril in freeze-dried Pt-C replicas and in negatively stained preparations for TEM. As three submicrofibril strands exit the wall of Axylinum , they twist together to form a left-hand helical microfibril. This process is driven by the left-hand helical structure of the submicrofibril and by cellulose synthesis. That is, as the submicrofibril is elongating at the wall, it is also being left-hand twisted and twisted together with two other submicrofibrils. The submicrofibril appears to have the dimensions of a nine (l-4)-ß-D-glucan parallel chain crystalline unit whose long, 23Å, and short, 19Å, diagonals form major and minor left-handed axial surface ridges every 36Å.The computer generated optical diffraction of this model and its corresponding image have been compared. The submicrofibril model was used to construct a microfibril model. This model and corresponding microfibril images have also been optically diffracted and comparedIn this paper we compare two less complex microfibril models. The first model (Fig. 1a) is constructed with cylindrical submicrofibrils. The second model (Fig. 2a) is also constructed with three submicrofibrils but with a single 23 Å diagonal, projecting from a rounded cross section and left-hand helically twisted, with a 36Å repeat, similar to the original model (45°±10° crossover angle). The submicrofibrils cross the microfibril axis at roughly a 45°±10° angle, the same crossover angle observed in microflbril TEM images. These models were constructed so that the maximum diameter of the submicrofibrils was 23Å and the overall microfibril diameters were similar to Pt-C coated image diameters of ∼50Å and not the actual diameter of 36.5Å. The methods for computing optical diffraction patterns have been published before.

Structural aspects of tracheary element differentiation in suspension cultures of Zinnia elegans

1989 ◽  
Vol 47 ◽  
pp. 768-769
Author(s):  
C. H. Haigler ◽  
A. W. Roberts
Keyword(s):  
Tracheary Element ◽  
Vesicle Fusion ◽  
Zinnia Elegans ◽  
Cellulose Synthesis ◽  
Tracheary Elements ◽  
Animal Cells ◽  
Mesophyll Cells ◽  
Fixation Techniques ◽  
Localized Patterns ◽  
Structural Aspects

Tracheary elements, the water-conducting cells in plants, are characterized by their reinforced walls that became thickened in localized patterns during differentiation (Fig. 1). The synthesis of this localized wall involves abundant secretion of Golgi vesicles that export preformed matrix polysaccharides and putative proteins involved in cellulose synthesis. Since the cells are not growing, some kind of endocytotic process must also occur. Many researchers have commented on where exocytosis occurs in relation to the thickenings (for example, see), but they based their interpretations on chemical fixation techniques that are not likely to provide reliable information about rapid processes such as vesicle fusion. We have used rapid freezing to more accurately assess patterns of vesicle fusion in tracheary elements. We have also determined the localization of calcium, which is known to regulate vesicle fusion in plant and animal cells.Mesophyll cells were obtained from immature first leaves of Zinnia elegans var. Envy (Park Seed Co., Greenwood, S.C.) and cultured as described previously with the following exceptions: (a) concentration of benzylaminopurine in the culture medium was reduced to 0.2 mg/l and myoinositol was eliminated; and (b) 1.75ml cultures were incubated in 22 x 90mm shell vials with 112rpm rotary shaking. Cells that were actively involved in differentiation were harvested and frozen in solidifying Freon as described previously. Fractures occurred preferentially at the cell/planchet interface, which allowed us to find some excellently-preserved cells in the replicas. Other differentiating cells were incubated for 20-30 min in 10(μM CTC (Sigma), an antibiotic that fluoresces in the presence of membrane-sequestered calcium. They were observed in an Olympus BH-2 microscope equipped for epi-fluorescence (violet filter package and additional Zeiss KP560 barrier filter to block chlorophyll autofluorescence).

Effects of release modifier on Carvedilol release from Kollidon SR based matrix

2012 ◽  
Vol 1 (8) ◽  
pp. 186 ◽  
Author(s):  
Urmi Das ◽  
Mohammad Salim Hossain
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Microcrystalline Cellulose ◽  
Matrix Tablets ◽  
Dissolution Time ◽  
Release Mechanism ◽  
Matrix Tablet ◽  
Weight Variation ◽  
The Matrix ◽  
Tablet Formulations

<p>Sustained release Carvedilol matrix tablets constituting Kollidon SR were developed in this study in an attempt to investigate the effect of release modifiers on the release profile of Carvedilol from matrix. Three matrix tablet formulations were prepared by direct compression of Kollidon SR in combination with release modifier (HPMC and Microcrystalline Cellulose) and magnesium stearate. Tablets containing only Kollidon SR with the active ingredient demonstrated a rapid rate of drug release. Incorporation of HPMC in the matrix tablet prolonged the release of drug but incorporation of Microcrystalline Cellulose showed superimposable release pattern with an initial burst effect as confirmed by mean dissolution time and Higuchi release rate data. After 7 hours of dissolution, Carvedilol release from the matrix systems were 91.42%, 83.41%, from formulation F1 and F2 respectively. Formulation F3 exhibited 100 % release at 4 hours. All the tablet formulations showed acceptable pharmaco-technical properties and complied with the in-house specifications for tablet weight variation, friability, hardness, thickness, and diameter. Prepared tablets also showed sustained release property for carvedilol. The drug release mechanism from the matrix tablets of F1 and F2 was found to be followed by Fickian and F3 by Non-Fickian mechanism.</p><p>DOI: <a href="http://dx.doi.org/10.3329/icpj.v1i8.11095">http://dx.doi.org/10.3329/icpj.v1i8.11095</a></p> <p>International Current Pharmaceutical Journal 2012, 1(8): 186-192</p>

Optimization of Microcrystalline Cellulose PH 101, Lactose, and Kollidon® K 30 To Obtain Co-Processed Excipient Through Spray Drying

2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Kusuma P. ◽  
Syukri Y ◽  
Sholehuddin F. ◽  
Fazzri N. ◽  
Romdhonah . ◽  
...  
Keyword(s):  
Spray Drying ◽  
Microcrystalline Cellulose ◽  
Chemical Change ◽  
Direct Compression ◽  
Flow Properties ◽  
Scanning Calorimetry ◽  
Compression Process ◽  
Infrared Spectrophotometer ◽  
Physical Mixtures ◽  
Spray Dried

The most efficient tablet processing method is direct compression. For this method, the filler-binder can be made by coprocessing via spray drying method. The purpose of this study was to investigate the effect of spray dried co-processing on microcrystalline cellulose (MCC) PH 101, lactose and Kollidon® K 30 as well as to define the optimum proportions. Spray dried MCC PH 101, lactose, and Kollidon® K 30 were varied in 13 different mixture design proportions to obtain compact, free-flowing filler-binder co-processed excipients (CPE). Compactibility and flow properties became the key parameters to determine the optimum proportions of CPE that would be compared to their physical mixtures. The result showed that the optimum proportion of CPE had better compactibility and flow properties than the physical mixtures. The optimum CPE, consisting of only MCC PH 101 and Kollidon® K 30 without lactose, that were characterized using infrared spectrophotometer, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscope (SEM) indicated no chemical change therein. Therefore, this study showed that spray dried MCC PH 101, lactose and Kollidon® K 30 could be one of the filler-binder alternatives for direct compression process.

β-Cyclodextrin Polymers on Microcrystalline Cellulose as a Granular Media for Organic Micropollutant Removal from Water

2018 ◽  
Author(s):  
Diego Alzate-Sanchez ◽  
Yuhan Ling ◽  
Chenjun Li ◽  
Benjamin Frank ◽  
Reiner Bleher ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Continuous Flow ◽  
Granular Media ◽  
Anaerobic Biodegradation ◽  
Thin Coating ◽  
Micropollutant Removal ◽  
Cyclodextrin Polymers ◽  
Flow Experiments ◽  
Aerobic And Anaerobic ◽  
Cellulose Composite

This manuscript describes cyclodextrin polymers formed as a thin coating on microcrystalline cellulose. The resulting polymer/cellulose composite shows promising performance for removing organic pollutants from water and can be packed into columns for continuous-flow experiments. The polymer/cellulose composite also shows excellent resistance to aerobic and anaerobic biodegradation.

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