217 research outputs found
New outlook on the minimal model program, I
We give a new and self-contained proof of the finite generation of adjoint
rings with big boundaries. As a consequence, we show that the canonical ring of
a smooth projective variety is finitely generated.Comment: to appear in Duke Math.
Birational automorphism groups of projective varieties of Picard number two
We slightly extend a result of Oguiso on birational or automorphism groups
(resp. of Lazi\'c - Peternell on Morrison-Kawamata cone conjecture) from
Calabi-Yau manifolds of Picard number two to arbitrary singular varieties X
(resp. to klt Calabi-Yau pairs in broad sense) of Picard number two. When X has
only klt singularities and is not a complex torus, we show that either Aut(X)
is almost cyclic, or it has only finitely many connected components.Comment: title slightly changed to this; some proof simplified; submitted to
the Proceedings of Groups of Automorphisms in Birational and Affine Geometry,
28 October - 3 November 2012, C.I.R.M., Trento, Ital
The Scale of Positive and Negative Experience (SPANE):Evaluation of Measurement Invariance and Convergent and Discriminant Validity
Positive Expectancies and Subjective WellāBeing: A Prospective Study Among Undergraduates in Serbia
Distribution of Craniofacial Variables in South Dalmatian and Middle Croatian Populations
The objective of the present work was to determine some relevant craniofacial parameters,
particularly in relation to sex, for the study of the distribution of basic head
and face types, and to investigate craniofacial and morphological differences between
two population samples. The study sample comprised 100 subjects of both sex aged 18 to
30 from South Dalmatia and 200 subjects from Middle Croatia. Eight basic craniofacial
variables were measured to obtain head, forehead and face indexes. The data indicate
that average values of all variables can be used as standard craniofacial parameters
for the examined population groups. All the craniofacial variables are considerably
higher in men than in women (p < 0.05). In the South Dalmatian population mesocephalia
(48.0%) and leptoprosopia (82.0%) prevail, while in the Middle Croatian population
the brachycephalia (62.0%), and euriprosopia (73.5%) are present to a greater degree.
The most significant craniofacial and morphological differences between the
examined study samples are head width (EuāEu), face width (ZyāZy), and forehead
height (TrāN). They were found to be statistically significant in the examined Middle
Croatian population (p < 0.05). The presented measurements are highly relevant to orthodontic
diagnostics and therapy
Structure and immunohistochemistry of the human lenticulostriate arteries
Background: Data about the structure and immunohistochemistry of the lenticulostriatearteries (LSAs), although very important for medical research and clinicalpractice, have been rarely reported in literature.Materials and methods: Fourty serially sectioned LSAs were stained with hematoxilinand eosin, and prepared for immunohistochemistry.Results: Our examination revealed a typical endothelial lining and a narrow subendothelialspace with subintimal smooth muscle cells occasionally. The internalelastic lamina was fragmented or absent in the smallest LSAs branches. The mediacoat, with a mean diameter of 148.5 Ī¼m, contained typical smooth muscle cellswhich formed 14.2 layers on average and showed a positive immune reactions foralfa-actin, desmine, laminin and collagen IV. The thin adventitial coat containedfibroblasts, collagen fibers, and nerve bundles, with the strongest immunopositivityto thyrosin hydroxilase. The immune reactions against CD31 and CD34 proteins,endothelial nitric oxide synthase, S 100 protein, neurofilament protein and synaptophysin,seem to be performed in the LSAs wall for the first time. Similarly,the thickness of the LSAs wall and its coats have never been reported, nor thenumber of the smooth muscle cell layers.Conclusions: Our results related to the structure and immunohistochemistry ofthe LSAs could be important in cerebrovascular pathology, neurology and neurosurgery
Improvement of water vapor barrier properties of chitosan-collagen laminated casings using beeswax
Collagen casings are commercially used in sausage production. In this paper, collagen film that is used for sausage casings was laminated with chitosan film to produce barrier casing film. Chitosan coating was prepared by dissolving chitosan powder in 1% acetic acid. After dissolving chitosan, caraway essential oil, wetting agent Tween 20 and different amounts of beeswax, from 0 to 25 g were added to the solution. The solution was coated on collagen film surface in three layers, using a sponge brush to make laminated films. Films were air dried at temperature t =23 Ā°C Ā± 2 Ā°C. Uncoated collagen film was used as reference. Film thickness, water vapor barrier properties and FTIR spectra were determined. With growing amount of beeswax added to the chitosan layer, film thickness grew from 112 Āµm for laminated film with 5 g of beeswax to 225 Āµm for film with 25 g of beeswax, compared to 83 Āµm for collagen film. Water vapor barrier properties improved with growing amount of beeswax in chitosan layer, ranging from 130.71 g/m2 24h for laminated film with added 5 g of beeswax to 66.96 g/m2 24h for the film with 25 g of beeswax, compared to 290.64 g/m2 24h for collagen film. Addition of beeswax showed great potential in lowering water vapor permeability of laminated collagen-chitosan film. FTIR spectra could be used to determine quantitative law dependency between added amount of beeswax and spectra absorption values,as well as to prove compactness of chitosan-beeswax layer
Supplementary material for the article: LaziÄ, A. M.; MaÅ”uloviÄ, A. D.; LaÄareviÄ, J. M.; ValentiÄ, N. V. Assessing the pharmacological potential of selected xanthene derivatives. Journal of the Serbian Chemical Society 2023, 88(9), 811-824. https://doi.org/10.2298/JSC230131035L
A convenient and efficient approach toward the synthesis of seven aromatically substituted xanthendiones 1ā7 and one structurally-related xanthenone 8 through condensation of dimedone and the appropriate aromatic aldehyde is reported. Further, their chemical structure was confirmed by melting points, elemental analysis, FT-IR, 1H-, 13C-NMR and UVāVis spectroscopic methods. The relationship between the chemical structure and pharmacological activity was determined empirically using appropriate software packages and in vitro using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method. The results of in silico prediction suggested that all investigated compounds possess good oral bioavailability. The results of the ABTS assay indicate that five compounds possess the ability to scavenge the ABTSā¢+ radical cation. Based on the comparison of the IC50 values, the activity of the compounds was found to be as follows: 6 > 1 > 7 > 2 > 8. The effects of solvent dipolarity/polarizability and solute solventāhydrogen-bonding interactions on the shifts of the absorption maxima were rationalized by means of the linear solvation energy relationship concepts proposed by KamletāTaft and CatalĆ”n.Related to: [https://technorep.tmf.bg.ac.rs/handle/123456789/6809]Supplementary material for: [https://doi.org/10.2298/JSC230131035L
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