Evolutionary relationships within ‘pygmaeus’ group microphallids using genetic analysis and scanning electron microscopy

2004 ◽  
Vol 78 (3) ◽  
pp. 231-236 ◽  
Author(s):  
K.V. Galaktionov ◽  
S.A. Bulat ◽  
I.A. Alekhina ◽  
D.H. Saville ◽  
S.M. Fitzpatrick ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Host Species ◽  
Final Host ◽  
Geographic Region ◽  
Cross Hybridization ◽  
Pcr Product ◽  
Wide Range ◽  
Polymerase Chain ◽  
Scanning Electron

AbstractThere are four species of ‘pygmaeus’ microphallids, namely Microphallus pygmaeus, M. piriformes, M. pseudopygmaeus and M. triangulatus (Trematoda: Microphallidae) which are parasites of marine birds and their sporocysts give rise to transmissible metacercariae inside littoral gastropods (mostly littorines). Universally primed polymerase chain reaction (UP-PCR) showed no apparent pattern between genetic diversity of the metacercariae as estimated by genomic banding profiles and their geographic region or molluscan host species. At the same time UP-PCR product cross-hybridization showed that M. pseudopygmaeus and M. triangulatus are genetically very similar, indicating that these taxa represent one species complex. In contrast, M. pygmaeus and M. piriformes are genetically well separated from each other and also from the pseudopygmaeus–triangulatus complex. Scanning electron microscopy of ventral spines, and analyses of spine angles and the number of teeth per spine, showed that all species differed significantly from one another. It was concluded that M. piriformes represents the original western member of the ‘pygmaeus’ group. Microphallus pygmaeus probably diverged from M. piriformes as it progressively specialized for sea duck final hosts. Microphallus pseudopygmaeus and M. triangulatus diverged from each other and the piriformes–pygmaeus ancestral line relatively recently. Microphallus pseudopygmaeus specialized for adoption of a wide range of gastropod host species and M. triangulatus developed morpho-functional specialization associated with final host exploitation.

Delamination Behavior of Cu-Low-k Stack Under Different Slurries

2003 ◽  
Vol 767 ◽  
Author(s):  
A. K. Sikder ◽  
S. Thagella ◽  
P. B. Zantye ◽  
Ashok Kumar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Mechanical Polishing ◽  
Wear Behavior ◽  
Polished Surface ◽  
Cu Metallization ◽  
Wide Range ◽  
Low K ◽  
Delamination Behavior ◽  
Scanning Electron

AbstractLower mechanical strength, reduced cohesive strength and lack of compatibility with other interconnect materials, are the major challenges involved in chemical mechanical polishing (CMP) of Cu metallization with ultra low-k materials as interlayer dielectrics. In this study we have investigated the polishing behavior of patterned Cu samples with underneath different low-k materials using two different slurries and a wide range of machine parameters. CMP micro tribometer was used to polish the samples with different rotations of platen (50 to 250 RPM) and down forces (1-6 PSI). Friction co-efficient and wear behavior were also investigated at different conditions. Optical and scanning electron microscopy was used to investigate the polished surface. It was observed that the two different Cu slurries used for polishing have marked effects on the polishing of Cu-low-k stack with respect to wear and delamination.

scholarly journals Dry Sliding Tribological Properties of a Hard Anodized AA6082 Aluminum Alloy

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 207
Author(s):  
Eleonora Santecchia ◽  
Marcello Cabibbo ◽  
Abdel Magid Salem Hamouda ◽  
Farayi Musharavati ◽  
Anton Popelka ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Behavior ◽  
Structure Characterization ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Alumina Layer ◽  
Wide Range ◽  
Wear Tests ◽  
Scanning Electron

The applications of aluminum and its alloys are still limited by low hardness and low wear resistance properties. Surface modifications, such anodizing and plasma electrolytic oxidation, represent a feasible way to overcome these drawbacks. In this study, discs of AA6082 were subjected to the so-called G.H.A. hard anodizing process leading to an anodized layer having a honeycomb-like structure. Samples having alumina layer thicknesses of 10, 50 and 100 μm were subjected to unidirectional dry sliding wear tests, using bearing steel and silicon nitride as counterbody materials. Surface and structure characterization of the samples were performed before and after the tribological tests, using a wide range of techniques; atomic force microscopy and scanning electron microscopy techniques were used before the wear tests. The wear scars were characterized by scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy techniques. Results show that the different thickness of the anodized layer does not affect the pores dimensions but has an influence on the micrometric domains in which the pores are divided. These features coupled with the wear test conditions, show to have a strong influence on the wear behavior. The thinnest sample showed also the best performance against the ceramic counterbody.

Synthesis of Fe2O3/CNTs for the Fast Removal of Tetracycline from Aqueous Solutions

2014 ◽  
Vol 915-916 ◽  
pp. 933-941 ◽  
Author(s):  
Zhong Jie Zhang ◽  
Chang Yu Lu ◽  
Wei Huang ◽  
Wei Sheng Guan ◽  
Yue Xin Peng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnetic Measurements ◽  
Ferrite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Fast Removal ◽  
Scanning Electron

The effective remove to tetracycline still remains a big challenge for scientists. In this work, we used a new method for preparing functional magnetic CNTS with ferrite nanoparticles. A wide range of techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and magnetic measurements were applied to characterize the obtained Fe2O3/CNTs. Moreover, we have also studied the properties of adsorbent to tetracycline. In addition, we have found that the Fe2O3/CNTs are better reusable adsorbent than other traditional adsorbents by magnetic separation recycling method.

scholarly journals TO THE QUESTION OF AN INTEGRATED RESEARCH OF BIOLOGICAL DAMAGE TO FIBROUS MATERIALS BY THE METHOD OF RASTER ELECTRON MICROSCOPY

2019 ◽  
Vol 20 (2) ◽  
pp. 522-534
Author(s):  
T. Balinyan ◽  
L. Derecha ◽  
Yu. Nosatenko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Higher Plants ◽  
Morphological Characteristics ◽  
Fibrous Materials ◽  
Blue Green Algae ◽  
Biological Damage ◽  
Wide Range ◽  
Scanning Electron ◽  
Comprehensive Study

The article considers the need for a comprehensive study of biological damage to fibrous materials by scanning electron microscopy. The main types and characteristics of fibers and fibrous materials, their types of damage, in particular, biological, and the mechanism of their formation are described. It is shown that with modern methods for studying morphological characteristics, the most effective is the method of scanning electron microscopy, which makes it possible to directly study the object in a wide range of magnifications. The use of scanning electron microscopy makes it possible to identify qualitatively new volumetric microsigns when conducting studies of fibrous materials. Biological damage agents (biofactors) are considered — microbiological (bacteria, microbes, fungi, blue-green algae), phytological (mosses, lichens, higher plants, algae), zoological (insects, birds, mammals). Attention is focused on the study of injuries caused by mold caused by moths, dogs, etc. Conducting a comprehensive study of various types of damage to materials of various fibrous nature allows us to obtain an information database, the possibility of differentiating chemical, mechanical, thermal and biological damage, identifying microsigns that individualize one or another object (factor) of action, influence, increasing the potential for obtaining trace information about the actual data and circumstances of the event in those cases when only by external morphological features of the diagnosis It is not possible to repair damage. The data obtained indicate the effectiveness of the chosen research area. The results of the studies are positive for creating the optimal research scheme, methods of microscopic studies of damage to materials of fibrous nature in order to solve diagnostic, identification and situational tasks of forensic examination.

scholarly journals A Complex Assemblage of Crystal Habits of Pyrite in the Volcanic Hot Springs from Kamchatka, Russia: Implications for the Mineral Signature of Life on Mars

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 535 ◽  
Author(s):  
Min Tang ◽  
Yi-Liang Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hot Springs ◽  
Morphological Features ◽  
Nutritional Elements ◽  
Wide Range ◽  
Life On Mars ◽  
Continuous Deposition ◽  
Microbial Mediation ◽  
Scanning Electron

In this study, the crystal habits of pyrite in the volcanic hot springs from Kamchatka, Russia were surveyed using scanning electron microscopy. Pyrite crystals occur either as single euhedral crystals or aggregates with a wide range of crystal sizes and morphological features. Single euhedral crystals, with their sizes ranging from ~200 nm to ~40 µm, exhibit combinations of cubic {100}, octahedral {111}, and pyritohedral {210} and {310} forms. Heterogeneous geochemical microenvironments and the bacterial activities in the long-lived hot springs have mediated the development and good preservation of the complex pyrite crystal habits: irregular, spherulitic, cubic, or octahedral crystals congregating with clay minerals, and nanocrystals attaching to the surface of larger pyrite crystals and other minerals. Spherulitic pyrite crystals are commonly covered by organic matter-rich thin films. The coexistence of various sizes and morphological features of those pyrite crystals indicates the results of secular interactions between the continuous supply of energy and nutritional elements by the hot springs and the microbial communities. We suggest that, instead of a single mineral with unique crystal habits, the continuous deposition of the same mineral with a complex set of crystal habits results from the ever-changing physicochemical conditions with contributions from microbial mediation.

Multi-Component One Pot assisted Synthesis, Anti-bacterial Capabilities and Scanning Electron Microscopy of Novel Corticosteroid Thiopyran

2020 ◽  
Vol 17 ◽  
Author(s):  
Sultanat ◽  
Anam Ansari ◽  
Mohd Qamar ◽  
Shafiullah ◽  
Sartaj Tabassum ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Disulphide ◽  
Building Blocks ◽  
Biologically Active ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Polycyclic Compounds ◽  
Wide Range ◽  
Scanning Electron

Background: Corticosteroids are important group of polycyclic compounds having a wide range of pharmacological and physiological properties. Thiopyran derivatives are important building blocks of many biologically active compounds. Objective: Keeping in mind the wide range of application of corticosteroid and thiopyran, herein we intend to develop a simple and efficient strategy to synthesize steroidal thiopyran derivatives starting with different commercially available corticosteroid and study their biological property. Materials and Methods: To achieve our aim, we employed a one-pot multicomponent synthesis of steroidal thiopyran derivatives by the reaction of corticosteriods, malononitrile and carbon disulphide in presence of triethyl amine as a catalyst. Results and Discussion : An array of novel thiopyran compounds were obtained with the highest product yield using Et3N. Scanning electron microscopy analysis manifested agglomeration pertaining to brick - shaped crystals of corticosteroid thiopyran. Synthesized compound were also found to be active as antibacterial agents. Conclusion: We describe a facile one-pot multicomponent synthesis of corticosteroid thiopyran derivatives which are found to possess antibacterial activity. Excellent yields of the products, simple work-up, easily available starting materials and non-chromatographic purification are some main advantages of this protocol.

scholarly journals Scanning electron microscopy and molecular dynamics of surfaces of growing and ablating hexagonal ice crystals

2010 ◽  
Vol 10 (6) ◽  
pp. 2927-2935 ◽  
Author(s):  
W. C. Pfalzgraff ◽  
R. M. Hulscher ◽  
S. P. Neshyba
Keyword(s):  
Electron Microscopy ◽  
Molecular Dynamics ◽  
Scanning Electron Microscopy ◽  
Ice Crystals ◽  
Variable Pressure ◽  
Free Standing ◽  
Hexagonal Ice ◽  
Ice Surface ◽  
Wide Range ◽  
Scanning Electron

Abstract. We present the first clearly resolved observations of surfaces of growing and ablating hexagonal ice crystals using variable-pressure scanning electron microscopy. The ice surface develops trans-prismatic strands, separated from one another by distances of 5–10 μm. The strands are present at a wide range of supersaturations, but are most pronounced at temperatures near the frost point. Pyramidal facets consistent with Miller-Bravais indices of 1011, and possibly also 2021, are associated with ice growth under these conditions. A molecular-dynamics model of a free-standing ice Ih nanocolumn containing 8400 water molecules does not develop trans-prismatic strands, suggesting these features originate at larger spatial or temporal scales. The possible relevance of these surface features to cirrus ice is discussed.

Melt electro written three-dimensional scaffolds engineered as oral microcosm models-an in vitro study.

2020 ◽  
Author(s):  
Srinivas Ramachandra ◽  
Abdulla Abdal-hay ◽  
Pingping Han ◽  
Ryan Lee ◽  
Saso Ivanovski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Confocal Microscopy ◽  
Pore Size ◽  
Next Generation ◽  
16S Sequencing ◽  
3 Dimensional ◽  
Wide Range ◽  
Scanning Electron ◽  
Medical Grade

<p><strong>Introduction</strong>: Biofilms are 3-dimensional (3D) aggregates of microorganisms that are associated with a wide range of diseases. Although there have been several studies investigating biofilm formation on two-dimensional substrates, the use of 3D substrates may result in more representative and clinically relevant models. Accordingly, the aim of this study was to compare the growth of biofilms in the 3D substrates against biofilms grown in 2D substrates.<br /><strong>Material and Methods:</strong> Two grams of medical grade polycaprolactone (PCL) were loaded into a plastic Luer-lock 3 ml syringe and a 23G needle was used as a spinneret. The syringe was placed in a melt electro-writing (MEW) device to obtain fine fibers under controlled parameters. The 3-dimensional MEW PCL scaffolds were manufactured and characterised with an overall thickness of ~ 0.8 mm, with ~ 15 μm diameter fibers and ordered pore sizes of either 100 or 250 µm. PCL films employed as 2D substrates were manufactured by dissolving 10 gms of PCL in 100 ml chloroform and stirred for 3 h to obtain a transparent solution. Then, the solution was cast in glass petri dishes and dried to remove all organic solvents. In addition, commercial hydroxyapatite discs were also used as 2D controls. Unstimulated saliva from six healthy donors (gingival health) were used to grow biofilms. The formed biofilms were assessed at day 4, day 7 and day 10 using crystal violet assay, confocal microscopy, scanning electron microscopy and next-generation 16s sequencing.<br /><strong>Results:</strong> The results demonstrates that 3D PCL scaffolds dramatically enhanced biofilm biomass and thickness growth compared to that of the 2D controls. Confocal microscopy of biofilms at day 4 stained with SYTO 9 and propidium iodide showed thickness of biofilms in 2D substrates were 39 µm and 81µm for hydroxyapatite discs and PCL films, respectively. Biofilms in 3D substrates were 250 µm and 338 µm for MEW PCL 100µm pore size and MEW PCL 250 µm pore size, respectively. Similar results were noticed at day 7 and day 10. Scanning electron microscopy showed biofilm bridges formed over the fibers of the MEW scaffolds. Pilot trials of next generation sequencing detected similar taxa in biofilms formed in 3D scaffolds compared to that of 2D substrates.<br /><strong>Discussion:</strong> We have successfully investigated a 3D biofilm growth model using 3D medical grade PCL scaffolds. Thicker biofilms can be conveniently grown using this inexpensive static model. This will facilitate 3D microbial community studies that are more clinically relevant and improve our understanding of biofilm-associated disease processes.</p> <p> </p>

Optimizing cellulose fibrillation for the production of cellulose nanofibrils by a disk grinder

Holzforschung ◽  
2015 ◽  
Vol 69 (8) ◽  
pp. 993-1000 ◽  
Author(s):  
Chuanshuang Hu ◽  
Yu Zhao ◽  
Kecheng Li ◽  
J.Y. Zhu ◽  
Roland Gleisner
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Consumption ◽  
Cellulose Nanofibrils ◽  
Solid Loading ◽  
Cumulative Energy ◽  
Microscopy Imaging ◽  
Rotating Speed ◽  
Wide Range ◽  
Scanning Electron

Abstract The fibrillation of a bleached kraft eucalyptus pulp was investigated by means of a laboratory-scale disk grinder for the production of cellulose nanofibrils (CNF), while the parameters disk rotating speed, solid loading, and fibrillation duration were varied. The cumulative energy consumption was monitored during fibrillation. The degree of polymerization (DP) and water retention value (WRV) of the resultant cellulose fibrils were determined as measures of the degree of fibrillation, which was also visualized by scanning electron microscopy, field emission-scanning electron microscopy, and transmission electron microscopy imaging. A higher rotating speed than 1500 rpm did not improve the fibrillation judged by DP and WRV measurements. Solid loading has an insignificant effect on fibrillation in a wide range. The energy consumption (E) was determined as a function of the DP and WRV. The optimal grinding conditions were between 1200 and 1500 rpm at 2.0%–2.2% solid loading.

scholarly journals ULTRAMICROSCOPIC CHARACTERISTICS OF ERYTHROCYTES IN INDIVIDUALS WITH BORRELIOSIS, RHEUMATOID ARTHRITIS AND TOXOPLASMOSIS AS A MARKER, COMORBID OR CONCOMITANT PATHOLOGY FOR BABESIOSIS

2021 ◽  
Vol 74 (9) ◽  
pp. 2066-2069
Author(s):  
Inna I. Torianyk
Keyword(s):  
Rheumatoid Arthritis ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polymerase Chain Reaction ◽  
Diagnostic Criteria ◽  
Constant Number ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Group 2 ◽  
Scanning Electron

The aim is to determine the ultramicroscopic characteristics of erythrocytes in individuals with rheumatoid arthritis, borreliosis or toxoplasmosis as a marker, comorbid or concomitant pathology for babesiosis. Materials and methods: Blood samples from the patients with revealed borreliosis (Lyme disease) (19 cases), toxoplasmosis (15 cases), rheumatoid arthritis in the stage ofexacerbation (10 cases) served as the study material (group 2). In all patients of group 2, positive results for babesiosis were obtained during the polymerase chain reaction. The group of comparative control (group 1) consisted of clinically healthy people (n=31), who underwent the blood cytological examination (light microscopy) preceding the scanning electron microscopy, followed by verification of the results by resources of molecular genetic research (polymerase chain reaction). Scanning electron microscopy was used in this study. Results: In patients with babesiosis and marker, comorbid and concomitant conditions for this disease (rheumatoid arthritis, borreliosis, toxoplasmosis) it was identified the specific diagnostic criteria for the presence of extraerythrocyte forms of babesia, constant number of erythrocytes and their regenerative forms, the appearance of degenerative forms of erythrocytes with their size and shape pathology. The latter lead to hemodynamic disorders, the development of ischemic and hypoxic changes in tissues of different organs of human body. Conclusions: Scanning electron microscopy of erythrocytes in patients with babesiosis and marker, comorbid and concomitant conditions for this disease (rheumatoid arthritis, borreliosis, toxoplasmosis) plays the role of an objective method of verifying the results of previous clinical and laboratory diagnosis. The use of scanning electron microscopy allow us to determine in these patients the specific diagnostic criteria for the presence of extraerythrocyte forms of babesia, constant number of erythrocytes and their regenerative forms, degenerative forms of erythrocytes with their size and shape pathology.

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