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1.
Effect of poly-[alpha], [gamma], L-glutamic acid as a capping agent on morphology and oxidative stress-dependent toxicity of silver nanoparticles
Magdalena Stevanović, Branimir Kovačević, Jana Nunić, Metka Filipič, Dragan Uskoković, 2011, original scientific article

Abstract: Highly stable dispersions of nanosized silver particles were synthesized using a straightforward, cost-effective, and ecofriendly method. Nontoxic glucose was utilized as a reducing agent and poly- α, γ, L-glutamic acid (PGA), a naturally occurring anionic polymer, was used as a capping agent to protect the silver nanoparticles from agglomeration and render them biocompatible. Use of ammonia during synthesis was avoided. Our study clearly demonstrates how the concentration of the capping agent plays a major role in determining the dimensions, morphology, and stability, as well as toxicity of a silver colloidal solution. Hence, proper optimization is necessary to develop silver colloids of narrow size distribution. The samples were characterized by Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, and zeta potential measurement. MTT assay results indicated good biocompatibility of the PGA-capped silver nanoparticles. Formation of intracellular reactive oxygen species was measured spectrophotometrically using 2,7-dichlorofluorescein diacetate as a fluorescent probe, and it was shown that the PGA-capped silver nanoparticles did not induce intracellular formation of reactive oxygen species.
Keywords: green synthesis, morphology, cytotoxicity
Published in DiRROS: 05.08.2024; Views: 112; Downloads: 103
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2.
Scaphoideus titanus up-to-the-minute : biology, ecology, and role as a vector
Elena Gonella, Giovanni Benelli, Nathalie Arricau-Bouvery, Domenico Bosco, Meta Virant-Doberlet, 2024, review article

Abstract: Native to the Nearctic region, Scaphoideus titanus Ball (Hemiptera: Cicadellidae) has become a major threat for grapevine production after being unintentionally introduced into Europe, where it became the main vector of flavescence dorée phytoplasma, being mainly associated with the genus Vitis. Scaphoideus titanus is a highly efficient vector of the most important phytoplasma affecting grapevine. For this reason, compulsory insecticide treatments have been introduced against this pest in many European countries. Moreover, the continuous expansion of its geographical distribution makes this leafhopper a serious threat for several non-European Countries. In this article, we review the current knowledge about its taxonomy, morphology, biology, ecology, and its role as a vector. Finally, we point out the main challenges for research aimed at reducing S. titanus and flavescence dorée expansion across Europe and avoiding spread of the disease outside the Old World.
Keywords: vector distribution, life cycle, morphology, taxonomy, feeding behaviour, entomology, insects
Published in DiRROS: 23.07.2024; Views: 135; Downloads: 88
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3.
Morphological features of breast cancer circulating tumor cells in blood after physical and biological type of isolation
Tanja Jesenko, Živa Pišljar, Cvetka Grašič-Kuhar, Maja Čemažar, Urška Matkovič, Simona Miceska, Jerneja Varl, Anamarija Kuhar, Veronika Kloboves-Prevodnik, 2021, original scientific article

Abstract: Background. Circulating tumor cells (CTCs) have become an important biomarker in breast cancer. Different iso-lation tech-niques based on their biological or physical features were established. Currently, the most widely used methods for visualization after their separation are based on immunofluorescent staining, which does not provide the information on the morphology.Materials and methods. The aim of this study was to evaluate how two different separation techniques affect cell morphology and to analyse cell morphology with techniques used in routine cytopathological laboratory. A direct side-by-side comparison of physical (Parsortix%) and biological (MACS%) separation technique was performed.Results. In the preclinical setting, both isolation techniques retained the viability and antigenic characteristics of MCF7 breast cancer cells. Some signs of degeneration such as cell swelling, cytoplasmic blebs, villous projections and vacuolization were observed. In metastatic breast cancer patient cohort, morphological features of isolated CTCs were dependent on the separation technique. After physical separation, CTCs with preserved cell morphology were detected. After biological separation the majority of the isolated CTCs were so degenerated that their identity was difficult to confirm.Conclusions. Taken together, physical separation is a suitable technique for detection of CTCs with preserved cell morphology for the use in a routine cytopathological laboratory.
Keywords: circulating tumor cells, breast cancer, morphology
Published in DiRROS: 22.07.2024; Views: 163; Downloads: 151
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Characterization of micro-threaded stem taper surface of cementless hip endoprostheses
Drago Dolinar, Boštjan Kocjančič, Klemen Avsec, Barbara Šetina, Aleksandra Kocijan, Matjaž Godec, Marko Sedlaček, Mojca Debeljak, John T. Grant, Timon Zupanc, Monika Jenko, 2024, original scientific article

Abstract: We investigated micro-threaded stem taper surface and its impact on premature failures, aseptic loosening, and infection in cementless hip endoprostheses. Our study focused on the fretting, and crevice corrosion of micro-threaded tapers, as well as the characterization of the microstructure and surface properties of two new and three retrieved Zweymüller stem tapers. The retrieved samples were selected and examined based on the head–stem taper interface being the sole source of modularity with a metallic component, specifically between the Ti alloy taper stem and the ceramic head. To determine the surface chemistry and microstructures of both new and retrieved hip endoprostheses stem taper titanium alloy, scanning -electron microscopy (SEM) was employed for morphological and microstructural analyses. Energy dispersive spectroscopy (EDS) was utilized for characterizing chemical element distribution, and electron backscattered diffraction (EBSD) was used for phase analysis. The roughness of the micro-threated stem tapers from different manufacturers was investigated using an optical profilometer, with standard roughness parameters Ra (average surface roughness) and Rz (mean peak to valley height of the roughness profile) being measured. Electrochemical studies revealed no fretting corrosion in retrieved stem tapers with ceramic heads. Consequently, three retrieved tapers and two new ones for comparison underwent potentiodynamic measurements in Hank’s solution to determine the corrosion rate of new and retrieved stem taper surfaces. The results showed a low corrosion rate for both new and prematurely failed retrieved samples due to aseptic loosening. However, the corrosion rate was higher in infected and low-grade infected tapers. In conclusion, our study suggests that using ceramic heads reduces taper corrosion and subsequently decreases the incidence of premature failures in total hip arthroplasty.
Keywords: total hip arthroplasty, stem micro-threaded taper, taper surface morphology, microstructure, corrosion, Ti implant alloy
Published in DiRROS: 06.06.2024; Views: 211; Downloads: 208
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6.
Two new species of Elaphoidella (Copepoda, Harpacticoida) from subterranean waters in Northeast Thailand, with a record of a gynandromorphic specimen and an up-to-date key to Elaphoidella species from Southeast Asia
Chaichat Boonyanusith, Anton Brancelj, La-orsri Sanoamuang, 2024, original scientific article

Abstract: Two new species of copepods of the genus Elaphoidella Chappuis, 1929 were discovered in a cave and a spring in northeastern Thailand. The first species, E. phuphamanensis sp. nov., belongs to species-group VII sensu Lang. It is most similar to E. turgisetosa Petkovski, 1980 in the armament of the male third exopod of the fourth swimming leg and the shape and armament of the fifth swimming leg in both sexes. However, it is easily distinguished from other congeners by the segmentation of the first swimming leg, the endopod of the fourth swimming leg, and the armature of the third exopod of swimming legs 2–4 in both sexes. The second species, E. propecabezasi sp. nov., is located in species-group I sensu Lang, where the male does not have a transformed seta on the third exopod of the fourth swimming leg and the female fifth swimming leg has four baseoendopodal robust setae, unequal in length. It is most similar to E. cabezasi Petkovski, 1982 and E. paraaffinis Watiroyram, Sanoamuang and Brancelj, 2017 in having the same armature formula as endopods 1–2 of female swimming legs 1–4. However, the ornamentation of the anal operculum, the shape of the caudal ramus, and the armature of the fifth swimming leg in both sexes distinguish them from each other. A rare gynandromorphic specimen of E. propecabezasi sp. nov. was recorded, and a revised key to Elaphoidella species in Southeast Asia is provided.
Keywords: cave-dwelling copepods, endemic distribution, groundwater habitats, intersex, morphology, zoology, Southeast Asia
Published in DiRROS: 17.05.2024; Views: 293; Downloads: 424
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7.
Diketopyrrolopyrrole pigment core@multi-layer ▫$SiO_2$▫ shell with improved photochemical stability
Erika Švara Fabjan, Zineb Saghi, Paul A. Midgley, Mojca Otoničar, Goran Dražić, Miran Gaberšček, Andrijana Sever Škapin, 2018, original scientific article

Abstract: A model organic pigment (diketopyrrolopyrrole) is encapsulated by a silica coating in order to improve its photochemical stability. Unlike in previous works where single-layer silica coatings were used for similar purposes, we here propose creation of a multi-layer silica shell synthesized via in-situ sol-gel method, which should significantly improve the homogeneity and thus the protection ability of the coating. This is done by repeating the basic two-step process (pigment surface modification and silica encapsulation) several times, creating the final protective shell in a layer-by-layer fashion. The compositional and structural properties of the prepared coatings is studied using Fourier-transform infrared spectroscopy, differential thermal and thermogravimetric analysis, nitrogen adsorption measurements and transmission electron microscopy. Photochemical stability of non-encapsulated and encapsulated pigment particles is evaluated via the so-called fast-irradiation method. Various correlations between the essential coating properties, such as thickness, porosity, SiO2 content, and the corresponding photochemical stability of the samples are established and discussed in detail. As a whole, our results confirm the basic hypothesis, that multiple-layered silica shells show improved pigment protection ability in comparison to the single-layer coatings.
Keywords: organic pigments, silica coating, encapsulation, morphology, photocemical stability
Published in DiRROS: 27.03.2024; Views: 440; Downloads: 176
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8.
Ornate Bairdiidae (Ostracoda) in 3 dimensions : exploring carapace morphology and pore canals of Triebelina van den Bold, 1946, Nodobairdia Kollmann, 1963 and Mirabairdia Kollmann, 1963
Marie-Béatrice Forel, Nathalie Poulet-Crovisier, Lidija Korat, Rosalie F. Maddocks, 2024, original scientific article

Abstract: Marine ostracods of the family Bairdiidae Sars, 1888 have an evolutionary history starting from the Ordovician with an explosive diversification of ornate forms during the Triassic. Representatives of the family are notoriously homeomorphic, which makes their taxonomy a major challenge of modern ostracodology. Their classification has thus been problematic since the 1970s. Here we present the first CT-scan investigation of recent and fossil ornate Bairdiidae valves in order to characterize and evaluate the taxonomic significance of unexploited characters, such as pores and pore canals. Thanks to 3D tomography, we explore the distribution of pores at the surface and the pathway of pore ca- nals within the valve wall of the recent genus Triebelina van den Bold, 1946 and the Triassic genera Nodobairdia Kollmann, 1963 and Mirabairdia Kollmann, 1963. In Triebelina indopacifica van den Bold, 1946, we describe an unexpected system of double pore canals, so far unknown in ostracods. We confirm that pore systems in Triebelina have largely intramural positions. In the Triassic Bairdiidae (Nodobairdia mammilata Kollmann, 1963 and Mirabairdia pernodosa Kollmann, 1963), we recognize simple unrimmed and massively nodular pores as well as marginal pores. Lateral normal pores of the Triassic specimens appear to be mostly in intra-solum positions. Although still exploratory and at the limits of the tomographic resolution, these observations provide new evidence to reject the formerly proposed synonymy of Triassic genera with Triebelina, which obstructed the establishment of a phylogenetic classification.
Keywords: ostracods, ornate Bairdiidae, morphology, normal pore canals, CT-scan, 3D analysis
Published in DiRROS: 08.03.2024; Views: 349; Downloads: 264
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9.
Pyrite with lower cubic symmetry from Lavrion, Greece
Mirjan Žorž, Panagiotis Voudouris, Branko Rieck, 2022, original scientific article

Abstract: V tej študiji smo preučili morfološke, kemijske in strukturne podrobnosti tetraedrsko oblikovanih kristalov pirita iz rudnika Jean Baptiste v Lavrionu. Pirit se pojavlja v treh generacijah. Prvo predstavljajo tetraedrski levo oziroma desno sučni kristali z najnižjo kubično 23 simetrijo. V tej generaciji so dvojčki z višjo kubično m_3 in heksagonalno 6 simetrijo. Vsi kristali druge generacije so že primarno zdvojčeni do kubične_4m3 simetrije. Nekateri pa se dvojčijo še naprej dokler ne dosežejo najvišje kubične m_3m ali heksagonalne 6mm simetrije. Kristali tretje generacije neorientirano prekrivajo kristale druge generacije. Kemijska analiza potrjuje kemijsko čist pirit, monokristalna rentgenska analiza kristalov prve in druge generacije pa za pirit značilno m_3 simetrijo. Očitno je torej, da morfološke oblike posameznih kristalov in dvojčkov kažejo na to, da imajo najnižjo kubično simetrijo, česar pa strukturna analiza ne potrjuje. Ta diskrepanca je lahko posledica spremenjenih pT pogojev in posledične transformacije prvotne strukture pirita s simetrijo 23 v sekundarno strukturo z m_3 simetrijo ali pa neoptimalnih pogojev pri določitvi strukture z rentgensko difrakcijo.
Keywords: Lavrion, pyrite, morphology, tetrahedral crystals, twins, point group 23, crystal structure
Published in DiRROS: 26.07.2022; Views: 869; Downloads: 314
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10.
Ecological time series and integrative taxonomy unveil seasonality and diversity of the toxic diatom Pseudo-nitzschia H. Peragallo in the northern Adriatic Sea
Timotej Turk Dermastia, Federica Cerino, David Stanković, Janja Francé, Andreja Ramšak, Magda Tušek-Žnidarič, Alfred Beran, Vanessa Natali, Marina Cabrini, Patricija Mozetič, 2020, original scientific article

Abstract: Pseudo-nitzschia H. Peragallo (1900) is a globally distributed genus of pennate diatoms that are important components of phytoplankton communities worldwide. Some members of the genus produce the neurotoxin domoic acid, so regular monitoring is in place. However, the identification of toxic members in routine samplings remains problematic. In this study, the diversity and seasonal occurrence of Pseudo-nitzschia species were investigated in the Gulf of Trieste, a shallow gulf in the northern Adriatic Sea. We used time series data from 2005 to 2018 to describe the seasonal and inter-annual occurrence of the genus in the area and its contribution to the phytoplankton community. On average, the genus accounted for about 15 % of total diatom abundance and peaked in spring and autumn, with occasional outbreaks during summer and large inter-annual fluctuations. Increased water temperature and decreased salinity positively affected the presence of some members of the genus, while strong effects could be masked by an unsuitable definition of the species complexes used for monitoring purposes. Therefore, combining morphological (TEM) and molecular analyses by sequencing the ITS, 28S and rbcL markers, eight species were identified from 83 isolated monoclonal strains: P. calliantha, P. fraudulenta, P. delicatissima, P. galaxiae, P. mannii, P. multistriata, P. pungens and P. subfraudulenta. A genetic comparison between the isolated strains and other strains in the Mediterranean was carried out and rbcL was inspected as a potential barcode marker in respect to our results. This is the first study in the Gulf of Trieste on Pseudo-nitzschia time series from a long-term ecological research (LTER) site coupled with molecular data. We show that meaningful ecological conclusions can be drawn by applying integrative methodology, as opposed to the approach that only considers species complexes. The results of this work will provide guidance for further monitoring efforts as well as research activities, including population genetics and genomics, associated with seasonal distribution and toxicity profiles.
Keywords: Pseudo-nitzschia, morphology, phylogeny, seasonality, time series, Adriatic Sea
Published in DiRROS: 18.03.2020; Views: 3020; Downloads: 1001
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