Micromorphological Differences Research Articles

In vitro microtomography evaluation of the implant-abutment interface - Gap microtomography evaluation/ Avaliação da microtomografia in vitro da interface implante-pilar - Avaliação da microtomografia de Gap

Objectives: To evaluate in vitro the micromorphological differences of the prosthetic implant-abutment interface in two screw implant systems and a friction one.Materials and methods: Two screw implants (Group 1- Crossfit Internal Connection, Group 2- Tapered Internal Connection), a compressed friction implant (Group 3 - Frictional Connection), and their corresponding prosthetic components were used. The implants were individually fixed in an acrylic resin cylinder and the abutments were positioned with the torque recommended by the manufacturer and taken into a SkyScan 1173 microtomograph. In each implant-abutment image, the regions of interest evaluated were cervical area, abutment area, screw area, and abutment and screw area (G1-G2). In group 3, the cervical and abutment areas were measured. Statistical analysis was performed with ANOVA, Robust ANOVA, and Post Hoc Tukey’s test.Results: In the cervical region, only the samples from group 2 presented maladaptation (12.5 ± 7.0 µm). In the abutment area, the samples from groups 1 (159.6 ± 6.2 µm) and 2 (149.9 ± 9.1 µm) were statistically similar. In the screw area and the abutment and screw area, group 1 had a larger contact surface compared to group 2 but they were statistically similar.Conclusion: The samples from groups 1 and 3 did not present micro-spaces in the cervical third. Nevertheless, the samples from group 2 presented a mismatch in this region but within the acceptable limits found in the literature.

Comparison of Amorphous Solid Dispersions of Spironolactone Prepared by Spray Drying and Electrospinning: The Influence of the Preparation Method on the Dissolution Properties.

This research aimed to compare two solvent-based methods for the preparation of amorphous solid dispersions (ASDs) made up of poorly soluble spironolactone and poly(vinylpyrrolidone-co-vinyl acetate). The same apparatus was used to produce, in continuous mode, drug-loaded electrospun (ES) and spray-dried (SD) materials from dichloromethane and ethanol-containing solutions. The main differences between the two preparation methods were the concentration of the solution and application of high voltage. During electrospinning, a solution with a higher concentration and high voltage was used to form a fibrous product. In contrast, a dilute solution and no electrostatic force were applied during spray drying. Both ASD products showed an amorphous structure according to differential scanning calorimetry and X-ray powder diffraction results. However, the dissolution of the SD sample was not complete, while the ES sample exhibited close to 100% dissolution. The polarized microscopy images and Raman microscopy mapping of the samples highlighted that the SD particles contained crystalline traces, which can initiate precipitation during dissolution. Investigation of the dissolution media with a borescope made the precipitated particles visible while Raman spectroscopy measurements confirmed the appearance of the crystalline active pharmaceutical ingredient. To explain the micro-morphological differences, the shape and size of the prepared samples, the evaporation rate of residual solvents, and the influence of the electrostatic field during the preparation of ASDs had to be considered. This study demonstrated that the investigated factors have a great influence on the dissolution of the ASDs. Consequently, it is worth focusing on the selection of the appropriate ASD preparation method to avoid the deterioration of dissolution properties due to the presence of crystalline traces.

A review of Convolvulus acanthocladus and its allies in Iran

The morphology and distribution of Convolvulus acanthocladus and its allies are reviewed. The group consists of C. acanthocladus, C. argyracanthus, C. iranicus and C. spinosus and a new species, C. hormodensis Ranjbar & Ezazi (Convolvulaceae), from Hormozgan province, southern Iran, which is described and illustrated. The paper highlights the macro- and micro-morphological differences between the five species and shows the value of trichome characters in distinguishing between species. The paper is illustrated with tables and photographs.

3D Structure and Processing Methods Direct the Biological Attributes of ECM-Based Cardiac Scaffolds

High hopes are held for cardiac regenerative therapy, driving a vast research effort towards the development of various cardiac scaffolds using diverse technologies and materials. Nevertheless, the role of factors such as fabrication process and structure in determining scaffold’s characteristics is yet to be discovered. In the present study, the effects of 3D structure and processing method on cardiac scaffolds are addressed using three distinct scaffolds made through different production technologies from the same biomaterial: decellularized porcine cardiac extracellular matrix (pcECM). pcECM patch, injectable pcECM hydrogel, and electrospun pcECM scaffolds were all proven as viable prospective therapies for MI, thus generally preserving pcECM beneficial properties. Yet, as we demonstrate, minor differences in scaffolds composition and micro-morphology as well as substantial differences in their mechanical properties, which arise from their production process, highly affect the interactions of the scaffold with both proliferating cells and functional cells. Hence, the rates of cell attachment, survival, and proliferation significantly vary between the different scaffolds. Moreover, major differences in cell morphology and alignment as well as in matrix remodeling are obtained. Overall, the effects revealed herein can guide a more rational scaffold design for the improved cellular or acellular treatment of different cardiac disease scenarios.

Ketidaksinambungan Litologi dan Karakteristik Pedogenetik pada Beberapa Andisols di Jawa Barat

Andisols developed from parent materials of volcanic eruptions. Volcanic eruptions can occur within several periods, resulting in a sequence of soil layers that can differ from each period and produced lithologic discontinuity in the soil profile. Lithologicac discontinuity was investigated in Andisols developed from the eruptions of Mt. Tangkuban Parahu (Holocene, andesitic) and Mt. Tilu (Pleistocene, basaltic) in West Java through morphological observations of three profiles at each location. The results showed that there was lithologic discontinuity in all profiles indicated by changed in color by Munsell Soil Colour Chart, organic carbon, texture and structure as the specific A buried horizon that developed from the parent material of the earlier eruption period than the horizons above. It is recommended to carry out the mineralogical and micromorphological analyses to determine the differences in minerals and micromorphology of the discontinue horizons and carbon-dating analysis in the buried layer to determine the age of the soil and the period of eruption that developed the soil. Keywords: A buried horizon, Munsell Soil Colour Chart, organic carbon, soil mineralogy, soil morphology

Catabolic changes of rat temporomandibular joint discs induced by unilateral anterior crossbite.

The temporomandibular joint (TMJ) disc plays a role in joint movement and in load absorbance and distribution. An experimental unilateral anterior crossbite (UAC) prosthesis induces mandibular condylar cartilage degeneration in rats. However, the changes in the articular disc are still unknown. To describe changes in the TMJ discs of UAC rats. The discs of fifty-four Sprague-Dawley rats, equally distributed into a UAC group and an age-matched sham-operated control group at 4, 12 and 20weeks (n=9), were evaluated by gross and histomorphological observation and by detection at the mRNA or protein expression levels of the markers related to the matrix elements. No macro- or micro-morphological differences were observed between groups. However, there were catabolic degradative changes at the molecular level in the UAC group, showing a significant reduction in the mRNA and/or protein expression levels of many molecules. The reduction became worse with time (P<0.05). The reduced molecules included: (a) those related to the extracellular matrix, such as type I collagen, decorin and fibromodulin; (b) those related to chondrogenesis, such as type II collagen and aggrecan; and (c) those related to osteogenesis, such as alkaline phosphatase and runt-related transcription factor 2. The mRNA expression of vascular endothelial growth factor did not change. In contrast, fibronectin, which can promote wound healing, and its N-terminal fragment, which can induce cartilage degradation, were accumulated (P<0.05). TMJ discs were stimulated to catabolic changes by the aberrant dental occlusion and seemed to go to inanimate with time.

Sobre el reconocimiento de Passiflora hibiscifolia (Passifloraceae, sección Dysosmia)

Antecedentes y Objetivos: Passiflora sección Dysosmia es considerado uno de los grupos más complicados dentro del género de pasionaria, debido en parte a la dificultad en delimitar adecuadamente sus taxa. Uno de esos ejemplos, actualmente reconocido como Passiflora ciliata var. hibiscifolia, ha sufrido una serie de cambios nomenclaturales basados en diversas opiniones taxonómicas desde su circunscripción en 1789. Hasta el presente, pocos investigadores han estudiado objetivamente la naturaleza única de este taxon o su afinidad con otros taxa similares en la sección. El objetivo de este estudio fue caracterizar el taxon actualmente conocido como P. ciliata var. hibiscifolia y proveer evidencia para su reconocimiento taxonómico.Métodos: Se realizaron estudios morfológicos intensos de 217 especímenes de herbario, incluyendo material tipo, además de 27 observaciones en iNaturalist.Resultados clave: Los resultados muestran diferencias significativas consistentes a nivel macro y micro morfológico entre el taxon conocido como P. ciliata var. hibiscifolia y todos los demás taxa en la sección Dysosmia.Conclusiones: La entidad estudiada es suficientemente distinta para concederle el reconocimiento de especie como Passiflora hibiscifolia.

Differences in micromorphology of the implant–abutment junction for original and third-party abutments on a representative dental implant

Statement of problemEvidence for micromorphology and precision of fit of third-party prosthetic components compared with the original manufacturer’s components is lacking. PurposeThe purpose of this in vitro pilot study was to evaluate the micromorphological differences among different commercial brands of zirconia, titanium, and gold abutments for dental implants in terms of tight surface contact. Material and methodsThe following abutments (n=3 per type) were preloaded on Straumann Bone Level implants according to the manufacturer’s instructions for zirconia (Zr, Zr2, Zr3), titanium (Ti and Ti2), and gold (Gold 1, Gold 2). The micromorphology of the implant–abutment units was investigated by using scanning electron microscopy (original magnification ×10 to ×500) after microtome sectioning. After we calibrated, the length of the areas with tight contact (TC) (discrepancy ≤3 μm) was calculated at the level of conical connection (CC), lower internal connection (LIC), and screw threads (STs). The interexaminer agreement was assessed by using intraclass correlation coefficient(s) (ICC). One-way ANOVA was used for the overall comparison of the Zr groups, and the Student paired t test was used for pairwise comparisons of the abutments of the same group. After we adjusted for multiple comparisons, the significance level for the overall and pairwise comparisons of Ti and Gold groups was set at a P value of .008 and a P value of .003 for the Zr groups. ResultsMajor differences were found among the different abutment types in terms of design and extent of surface contact. The TC showed significant differences among the abutments of Zr group, depending on the side and level of evaluation (Zr1 > Zr2 > Zr3 on the left side for CC; Zr1, Zr2 > Zr3 on the right side for CC, and, Zr2 > Zr3 on the right side for LIC; P<.003). In Ti group, no significant differences were found (P>.008). The Gold and Gold 2 groups had significantly greater contact on the left side of CC (P<.008). ConclusionsA difference in design of the abutments was apparent. The tight surface contact was significantly different among the examined abutments or abutment screws and the respective area of the inner surface of the implants.

Subchondral bone morphology in the metacarpus of racehorses in training changes with distance from the articular surface but not with age.

The repetitive large loads generated during high-speed training and racing commonly cause subchondral bone injuries in the metacarpal condyles of racehorses. Adaptive bone modelling leads to focal sclerosis at the site of highest loading in the palmar aspect of the metacarpal condyles. Information on whether and how adaptive modelling of subchondral bone changes during the career of a racehorse is sparse. The aim of this cross-sectional study was to describe the changes in subchondral bone micromorphology in the area of highest loading in the palmar aspect of the metacarpal condyle in thoroughbred racehorses as a function of age and training. Bone morphology parameters derived from micro-CT images were evaluated using principal component analysis and mixed-effects linear regression models. The largest differences in micromorphology were observed in untrained horses between the age of 16 and 20months. Age and duration of a training period had no influence on tissue mineral density, bone volume fraction or number and area of closed pores to a depth of 5.1mm from the articular surface in 2- to 4-year-old racehorses in training. Horses with subchondral bone injuries had more pores in cross-section compared with horses without subchondral bone injuries. Differences in bone volume fraction were due to the volume of less mineralised bone. Tissue mineral density increased and bone volume fraction decreased with increasing distance from the articular surface up to 5.1mm from the articular surface. Further research is required to elucidate the biomechanical and pathophysiological consequences of these gradients of micromorphological parameters in the subchondral bone.

Micro-morphological adaptations of the wing nodus to flight behaviour in four dragonfly species from the family Libellulidae (Odonata: Anisoptera)

Adult dragonflies can be divided into two major groups, perchers and fliers, exhibiting notably different flight behaviour. Previous studies have yielded conflicting results regarding the link between the wing macro-morphology and flight style in these two groups. In this study, we present the first systematic investigation of the micro-morphological differences of wings of percher and flier dragonflies in four closely related species from the family Libellulidae. Our results suggest that the shape and material composition of wing microstructural components and, in particular, the nodus are adapted to facilitate the specific wing functioning in fliers and perchers. The findings further indicate a decreasing trend in the area proportion of the soft resilin-dominated cuticle in the nodus in the series of species from typical perchers to typical fliers. Such a reduction in the resilin proportion in the nodus of fliers is associated with an increase in the wing aspect ratio. The knot-shaped protrusion at the nodus of perchers, which becomes notably smaller in that of strong fliers, is likely to act as a mechanical stopper, avoiding large wing displacements. This study aims to develop a novel framework for future research on the relationship between wing morphology and flight behaviour in dragonflies.

3D analysis of cut marks using a new geometric morphometric methodological approach

The arrival of new methodological approaches to study microscopic qualities in cut mark morphology has been a major improvement in our understanding of butchering activities. Micro-morphological differences can be detected in multiple different taphonomic alterations on bone cortical surfaces that can later be used to compare different trace mark types. Through this, we can generate studies that are able to diagnose the specific taphonomic agents and activities that produce said traces that can be found on osteological surfaces. This paper presents experimental data that have been studied using micro-photogrammetry and geometric morphometrics, successfully distinguishing morphological differences in cut marks produced by different lithic tool types as well as different raw materials. The statistical results and methodologies presented here can later be applied to archaeological sites; aiding in our understanding of raw material exploitation, tool production as well as the different butchering activities that are present in faunal assemblages.

Micromorphological differences of the implant-abutment junction and invitro load testing for three different titanium abutments on Straumann tissue level implants.

The aim of this study was to investigate the micromorphological differences among three commercially available titanium abutments on Straumann implants. Furthermore, the possible impact of functional loading on the micromorphology and potential complications was investigated with the use of invitro testing. Three groups of Titanium abutments (A: Straumann Variobase n=5, B: EBI best Duo n=5, and C: Implant Direct n=5) were torqued on Straumann RN implants, as according to each of the manufacturer's instructions. The implant-abutment units were scanned with Micro-CT. Three units of each group were directly sliced in the microtome and photographed under different magnifications (10×-500×) through a Scanning Electron Microscope. Six units (two from each group) were restored with cement-retained crowns, subjected to 2000,000 load cycles with loads between 30 and 300N at 2Hz, examined through Micro-CT and finally sliced and photographed as described above. The micromorphology of each unit was studied, and the total length of tight contact (<3μm) was calculated between the implant, abutment and screw contact areas. Major morphological differences were identified between the three units, as well as differences in the extent of tight contact in all areas examined. Despite the morphological differences, the 2M cycles of loading via invitro test did not result in any noticeable complications although some changes in the micromorphology were observed. The examined implant-abutment units presented with major morphological differences. Two million cycles of invitro loading did not appear to affect the stability of the units despite the micromorphological changes. These results need to be interpreted however under the limitations of the small sample size and the specific set-up of the invitro testing.

In vitro evaluation of onlay restorations on primary teeth.

Many novel materials have been developed such as composite resin, ceramic, zircon or metal-supported ceramic for use in aesthetic restoration of primary teeth and permanent teeth with extensive crown damage. The aim of the present study was to compare microtensile bond strengths on materials using the microtensile bond strength test. The microtensile bond strength on the primary tooth dentin was measured on extracted primary teeth using an indirect method and fracture patterns were evaluated. The analysis of bond strengths using the Mann-Whitney U-test did not show significant difference between the rank averages of the compomer and composite resin (p = 0.741). The dentin sections, from which test samples were obtained, contributed to the bond strength; dentin samples obtained just above the pulp had lower bond strength, and the difference was statistically significant (p = 0.005). The adhesive type fracture was the most prevalent fracture type for both materials. When the chemical, physiological, and micromorphological differences between primary and permanent teeth are taken into consideration, the success of the materials used for restorations can be different between primary and permanent teeth. Therefore, materials used in the dentistry must be evaluated separately for primary teeth.

Characteristics and generation mechanisms of coal fines in coalbed methane wells in the southern Qinshui Basin, China

Coal fines produced in coalbed methane (CBM) wells from various geologic settings at different well production stages from coal seam #3 in the southern Qinshui Basin were investigated. Particle size measurements, micro-morphology and mineralogy using grain size analysis, environmental scanning electronic microscopy (ESEM), X-ray diffraction (XRD), and a coal fines transport experiment were performed. By comparing grain size compositions of the coal fines from the underground coal mines and drill cuttings, the genetic types and mechanisms of coal fines from different production stages of CBM wells were described, and their significance to CBM production was discussed. The results indicate significant differences in particle size, micro-morphology, mineralogy, and genetic type of coal fines produced during different stages of CBM wells. During the water production stage, coal fines in CBM wells are primarily produced by washing the fracture surfaces with the fracturing proppant. Coal fines of this genetic type are relatively small and have sheet and flat block shapes because of grinding by the proppant. Brittle minerals, such as quartz and pyrite, are the major minerals in these coal fines because of the intermixing of quartz from the proppant and the preferential mineral transport and enrichment during pulverization; additionally, the brittle minerals content exceeds that in the raw coal by a factor of five or more. During the gas production stage, coal fines from CBM wells primarily consist of coal that was originally crushed by tectonic stress, generated between partings and the coal floor or in a fault zone. Brittle minerals are formed by shearing along the fault or via coal bed fragmentation in the floor rock during folding. In this case, the coal fines are relatively large and have block or thick, flat block shapes, suggesting that the coal fines have not experienced strong shearing after their formation. Similar to the coal fines from the water production stage, the minerals in the coal fines are mostly brittle, although their degree of enrichment is relatively low. Overall, the characteristics and genetic mechanisms of coal fines determine their grain size, total quantity, and the extent to which they can be transported by fluids. Coal fines play an important role in determining the coal structure, the development of the coal deposit, and the parameters of methane production management and control.

Climatic interpretation of loess-paleosol sequences at Mobarakabad and Aghband, Northern Iran

AbstractLoess accumulation and paleosol formation are important Quaternary geoarchives in northern Iran. Two loess-paleosol sequences at Mobarakabad and Aghband were examined using soil morphology and micromorphology, mineralogy, magnetic susceptibility (MS), free Fe oxides and calcium carbonate equivalent. The loess-paleosol sequences provide a record of changes in paleo-rainfall in the northern Iran. Micromorphological and MS differences between the loess and paleosols in the sections reflect changes in climate. The different behaviors of magnetic susceptibility between Aghband and Mobar-akabad loess are mainly produced by their different pedogenic environments, topography and climatic conditions. As a result, the MS at the Mobarakabad section is much higher than at Aghband. Paleoeco-logical reconstructions coupled with magnetic depletion in paleosols at Mobarakabad suggest a wetter climate dominating during the formation of the paleosols.

Leaf epidermal characteristics and classification of sections of {\sl Leymus} from China

The leaf epidermises of 15 species of Leymus were examined under the light microscope.It was found that these micromorphological differences shown by the lower epidermis may be applied to dividing the Chinese Leymus species into three groups.And in accordance with the external characteristics of each group,these three groups should separately belong to sect.Leymus,sect.Aphanoneuron and sect.Anisopyrum which were described by our predecessors.Moreover,according to the variation trends of leaf epidermal characters,the relationships among three Chinese sections were analysed as well.The results show that sect.Leymus is the most primitive and sect.Anisopyrum is the most advanced among three sections,whereas sect.Aphanoneuron lies between the above two sections;sect.Anisopyrum shows direct relationship with sect.Aphanoneuron,but indirect relationship with sect.Leymus.

A cytogenetic study of R. constantinopolitanus and R. sericeus (Ranunculaceae) in Iran

With 600 species Ranunculus is the largest genus in Ranunculaceae, and has a broad global distribution. We studied the karyotypes of R. constantinopolitanus and R. sericeus species of Ranunculaceae and identified their symmetry level. New chromosome numbers of 2n = 21 (Nodeh woods population) and 2n ca. 63 (Javaherdeh population) are reported for R. constantinopolitanus. Two different populations of R. sericeus had two different chromosome results. We investigated morphological and karyological studies along with pollens micromorphology. Different populations of R. constantinopolitanus and R. sericeus, with different chromosome numbers showed morphological and micromorphological differences. Therefore, we considered the two populations of R. sericeus as cytotypes. There was a correlation between the studied morphological characters and pollen size with ploidy levels in the two R. constantinopolitanus populations.

Taxonomic Utility of Lemma Micromorphological Characters in theSporobolus compositusandSporobolus VaginiflorusComplexes (Poaceae)

Five lemma micromorphological characters including bicellular microhairs, hooks, long cells, prickles, and silica cells of six Sporobolus taxa representing the S. compositus and S. vaginiflorus complexes in Texas were investigated using scanning electron microscopy (SEM). Our study supplements earlier SEM treatments of Sporobolus in Valdes-Reyna & Hatch and Liu et al. and colleagues. The micromorphological differences found by our study support the taxonomic treatment of these two complexes by Peterson et al.

A new species of Tremella from Macaronesia

Tremella laurisilvae, a species new to science with a parasitic strategy on Biscogniauxia species, is described from the evergreen laurel forests of Macaronesia. The basidiocarps are macroscopically differentiated by finger-like lobes and brown-orange colour. Micromorphological differences with phylogenetically related species are evaluated and its phylogenetic placement in Tremellomycetes is inferred from ITS rDNA sequences. A detailed description, plate with photographs and a key to species from Europe and Macaronesia are provided.

Investigating the micromorphological differences of the implant-abutment junction and their clinical implications: a pilot study.

The aim of this pilot study was to investigate the morphological micro-features of three commercially available implant-abutment joints, using compatible and original prosthetic components. Furthermore, possible correlations between the micromorphology and potential functional complications were investigated with the use of finite element analysis. Three abutments (one original and two compatibles) were torqued on original Straumann RN implants, as according to each of the manufacturer's instructions. The implant-abutment units were sliced in the microtome and photographed under different magnifications (10×-500×) through a scanning electron microscope. Finite element analysis models were reconstructed for each of the implant-abutment units using the precise measurements from the SEM. Differences in stress, strain and deformation for the three different abutments were then calculated using ANSYS Workbench v13. Major dimensional differences were identified between all studied contact areas of the three units. The tight contact in the implant shoulder was similar in all three units, but engagement of the internal connection and, in particular, the anti-rotation elements was seriously compromised in the compatible abutments. One compatible abutment demonstrated compromised engagement of the abutment screw as well. Equivalent stress and strain in the FEA were much higher for the compatible abutments. An evaluation of the sequence of preload application revealed differences in the pattern of deformation between the original and compatible abutments, which can have serious clinical implications. Compatible abutments can present critical morphological differences from the original ones. The differences in the cross-sectional geometry result in large differences in the overall contact areas, both in terms of quality and quantity which could have serious implications for the long-term stability of the prosthesis.