Quality Indicators of Ammonium Nitrate with Nanoporous Surface Structure: Final Drying Stage

Author(s):  
Nadiia Artyukhova ◽  
Jan Krmela ◽  
Vladimira Krmelova
2016 ◽  
Vol 31 (6) ◽  
pp. 807-818 ◽  
Author(s):  
Sungwon Kim ◽  
Cheonil Park ◽  
Byeong-Seok Moon ◽  
Hyoun-Ee Kim ◽  
Tae-Sik Jang

Owing to the excellent bioactive properties of recombinant human bone morphogenetic proteins (rhBMPs), dentistry considers them as a fascinating adjuvant alternative for enhancing bone regeneration and bone-to-implant junction in the early implantation stages. However, stable loading and delivery efficiency of rhBMPs on the implant surfaces involve major concerns because of the harsh wearing condition under load during implantation. In this study, to achieve successful rhBMP-2 delivery, a nanoporous surface structure is introduced on the sandblasting with large grit and acid-etching (SLA)-treated titanium (Ti) surface via the tantalum (Ta) target-ion induced plasma sputtering (TIPS) technique. Unlike oxidation-induced surface nanoporous fabrications on a Ti surface, TIPS-treated surfaces provide excellent structural unity of the nanoporous structure with the substrate due to their etching-based fabrication mechanism. SLA/TIPS-treated Ti exhibits distinct nanoporous structures on the microscale surface geometry and better hydrophilicity compared with SLA-treated Ti. A sufficiently empty nanoporous surface structure combined with the hydrophilic property of SLA/TIPS-treated Ti facilitates the formation of a thick and uniform coating layer of rhBMP-2 on the surface without any macro- and microcoagulation. Compared with the SLA-treated Ti surface, the amount of coated rhBMP-2 increases up to 63% on the SLA/TIPS-treated Ti surface. As a result, the in vitro pre-osteoblast cell response of the SLA/TIPS-treated Ti surface, especially cell adhesion and differentiation behaviors, improves remarkably. A bone-regenerating direct comparison between the rhBMP-2-coated SLA-treated and SLA/TIPS-treated Ti is conducted on a defective dog mandible model. After 8 weeks of implantation surgery, SLA/TIPS-treated Ti with rhBMP-2 exhibits a better degree of contact area for the implanted bone, which mineralizes new bones around the implant. Quantitative results of bone-in-contact ratio and new bone volume also show significantly higher values for the SLA/TIPS-treated Ti with the rhBMP-2 specimen. These results confirm that an SLA/TIPS-treated surface is a suitable rhBMP-2 carrier for a dental implant to achieve early and strong osseointegration of Ti dental implants.


2021 ◽  
Vol 16 (4) ◽  
pp. 38-41
Author(s):  
Kseniya Zayceva

The purpose of the study is to identify the effectiveness of various types of fertilizers and biologics Bisolbifit on the yield and quality indicators of spring barley grain. Experiments were conducted in 2015-2017 in Ulyanovsk region. The soil of the experimental site is represented by leached Chernozem, heavy loam. The scheme of experience included two factors. Factor A-control; pre-sowing seed treatment with Bisolbifit; NPK in pure form at a dose of 15 kg of active substance per hectare; modified NPK (NPKm) at a dose of 15 kg of active substance per hectare; modified NPK (1/2 NPKm) at a dose of 7.5 kg of active substance per hectare. Factor B (background): zero-without fertilizers; pure ammonium nitrate (NH4NO3) at a dose of 40 kg of active substance per hectare; modified ammonium nitrate (1/2 NH4NO3m) at a dose of 20 kg of active substance per hectare. Inoculation of seeds with a biological preparation was performed by semi-dry etching 1...2 days before sowing at a dose of 400...600 g per hectare of seeds. For the preparation of modified NPK and ammonium nitrate, the biological preparation Bisolbifit was used in a dose of 4 kg per 1 ton of fertilizers. The drug was applied to mineral fertilizer granules on the day of sowing. All types of fertilizers and biologics studied led to an increase in yield. The use of mineral fertilizers in pure form (untreated with biologics) increased the yield by 0.26...0.41 t/ha, modified – by 0.38...0.54 t/ha, biologics – by 0.06...0.19 t/ha, compared with the control (2.67 t/ha). The use of fertilizers and biologics increased the weight of 1000 grains – the best options were with modified NPK at a dose of 15 kg d. V./ha-49.4...53.0 g. the quality indicators of the studied agricultural practices did not have a significant impact. The highest payback of fertilizers by increasing the yield was recorded in the variant with pre-sowing treatment of seeds with Bisolbifit biologics and amounted to 7.7...11.4 kg/kg


Author(s):  
Sanford H. Vernick ◽  
Anastasios Tousimis ◽  
Victor Sprague

Recent electron microscope studies have greatly expanded our knowledge of the structure of the Microsporida, particularly of the developing and mature spore. Since these studies involved mainly sectioned material, they have revealed much internal detail of the spores but relatively little surface detail. This report concerns observations on the spore surface by means of the transmission electron microscope.


Author(s):  
Robert M. Glaeser ◽  
Thea B. Scott

The carbon-replica technique can be used to obtain information about cell-surface structure that cannot ordinarily be obtained by thin-section techniques. Mammalian erythrocytes have been studied by the replica technique and they appear to be characterized by a pebbly or “plaqued“ surface texture. The characteristic “particle” diameter is about 200 Å to 400 Å. We have now extended our observations on cell-surface structure to chicken and frog erythrocytes, which possess a broad range of cellular functions, and to normal rat lymphocytes and mouse ascites tumor cells, which are capable of cell division. In these experiments fresh cells were washed in Eagle's Minimum Essential Medium Salt Solution (for suspension cultures) and one volume of a 10% cell suspension was added to one volume of 2% OsO4 or 5% gluteraldehyde in 0.067 M phosphate buffer, pH 7.3. Carbon replicas were obtained by a technique similar to that employed by Glaeser et al. Figure 1 shows an electron micrograph of a carbon replica made from a chicken erythrocyte, and Figure 2 shows an enlarged portion of the same cell.


Author(s):  
S. S. Breese ◽  
H. L. Bachrach

Models for the structure of foot-and-mouth disease virus (FMDV) have been proposed from chemical and physical measurements (Brown, et al., 1970; Talbot and Brown, 1972; Strohmaier and Adam, 1976) and from rotational image-enhancement electron microscopy (Breese, et al., 1965). In this report we examine the surface structure of FMDV particles by high resolution electron microscopy and compare it with that of particles in which the outermost capsid protein VP3 (ca. 30, 000 daltons) has been split into smaller segments, two of which VP3a and VP3b have molecular weights of about 15, 000 daltons (Bachrach, et al., 1975).Highly purified and concentrated type A12, strain 119 FMDV (5 mg/ml) was prepared as previously described (Bachrach, et al., 1964) and stored at 4°C in 0. 2 M KC1-0. 5 M potassium phosphate buffer at pH 7. 5. For electron microscopy, 1. 0 ml samples of purified virus and trypsin-treated virus were dialyzed at 4°C against 0. 2 M NH4OAC at pH 7. 3, deposited onto carbonized formvar-coated copper screens and stained with phosphotungstic acid, pH 7. 3.


Author(s):  
D. Johnson ◽  
P. Moriearty

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.


Author(s):  
O.L. Krivanek ◽  
G.J. Wood

Electron microscopy at 0.2nm point-to-point resolution, 10-10 torr specimei region vacuum and facilities for in-situ specimen cleaning presents intere; ing possibilities for surface structure determination. Three methods for examining the surfaces are available: reflection (REM), transmission (TEM) and profile imaging. Profile imaging is particularly useful because it giv good resolution perpendicular as well as parallel to the surface, and can therefore be used to determine the relationship between the surface and the bulk structure.


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