Analytical time-like geodesics

Time-like orbits in Schwarzschild space-time are presented and classified in a very transparent and straightforward way into four types. The analytical solutions to orbit, time, and proper time equations are given for all orbit types in the form r=r(\lambda), t=t(\chi), and \tau=\tau(\chi), where \lambda\ is the true anomaly and \chi\ is a parameter along the orbit. A very simple relation between \lambda\ and \chi\ is also shown. These solutions are very useful for modeling temporal evolution of transient phenomena near black holes since they are expressed with Jacobi elliptic functions and elliptic integrals, which can be calculated very efficiently and accurately.Comment: 15 pages, 10 figures, accepted by General Relativity and Gravitatio

Phytochemical Analysis and Total Antioxidant Capacity of Rhizome, Above-Ground Vegetative Parts and Flower of Three Iris Species

This study was aimed at investigating the phytochemical composition and antioxidant capacity of rhizomes, above-ground vegetative parts and flowers of three Iris species: Iris humilis Georgi, Iris pumila L. and Iris variegata L. UHPLC-Orbitrap MS analysis was used for determination of phytochemical profile. Total pigments, phenolics, flavonoids, soluble sugars and starch content as well as ABTS antioxidant capacity were also determined. In total, 52 phenolics compounds were identified with 9 compounds (derivatives of iriflophenone, apigenin C-glycosides, luteolin O-glycoside, isoflavones derivatives of iristectorigenin, dichotomitin, nigracin and irilone) never reported before in Iris spp. Differences in phenolic composition profile, pigments, soluble sugar, starch, total phenolics and flavonoids content and total antioxidant capacity were found among Iris species and different part of plants. Significant correlation between total phenolic content and antioxidant capacity was determined. The obtained results are comparable with those obtained for medical plants. These findings could be useful for fingerprinting characterization of Iris species and estimation of possible use in pharmaceutical industries

Carotenoids: New Applications of “Old” Pigments

Carotenoids represent a large group of mainly red, orange, and yellow natural metabolites mainly involved in regulation of many metabolic processes. Carotenoids are beneficial for human health. Current study describes the importance, chemical composition and functioning of carotenoids. It is well known that carotenoids support pigments acting in light absorbance mechanisms during photosynthesis, and are known to protect the chlorophyll molecules from oxidative stress and reactive oxygen species (ROS) damage. Carotenoids are involved in signaling processes in plants, responses to environmental stresses, pollination, germination and reproduction, and development regulation. As nutrients of strong antioxidant activity that is primarily linked to their polyene molecular structure, the carotenoids are reported as immune-enhancement and anticancer agents, which are also involved in prevention of eye-, gastric and neurocognitive disorders, and in regulation of obesity and anti-ageing. Concern-ing the wide prospective applications of carotenoids as pharmaceuticals and nutraceuticals, there are some critical aspects associated with carotenoids’ bioavailability and challenges in their bioengineering. This mostly refers to the needs for identification and cloning of genes responsible for carotenoid biosynthesis and transformation and related development of transgenic carotenoid-rich crops. In the recent years, technologies of micro-and nanoencapsulation have addressed the needs of carotenoid entrapping to enhance their bioavailability, solubility and chemical stability, and to ensure the target delivery and manifestation of their strong antioxidant and other biological activity. Among standard and some advanced analytic tools for carotenoid determination (e.g., High performance liquid chromatography-HPLC, Liquid chromatography–mass spectrometry-LC-MS, Ultra high performance liquid chromatography-UHPLC, High-performance thin-layer chromatography-HPTLC and others), the vibrational spectroscopy techniques, primarily Raman spectroscopy coupled with chemometric modeling, opened a new era in carotenoid research and application

Position and size of massa intermedia in Serbian brains

Background: Massa intermedia, a midline bar-shaped structure, connects two thalami across the third ventricle in 70–80% of healthy humans. It has become clinically important since its absence was comprehended as a midline malformation of the brain and brought in connection with schizophrenia indicating that some symptoms could be a consequence of disturbed neuron chains underlying the mechanisms of attention and processing of information. The aim of the investigation was to find out the incidence, position, and size of massa intermedia in the brains of the Serbian population. Materials and methods: Our investigation was performed on 41 brains of adult Serbian cadavers using a macro dissection method. Results: Massa intermedia was present in 80.49% of cases, in 1 case it was double. In most of the cases it was located in the superior quadrants of the lateral wall of the third ventricle, the larger part being in the anterosuperior one. Some other combinations were also present. The horizontal diameter of the cross-section was larger than vertical and was not in correlation with the length of the third ventricle. The average cross-sectional area was 29.58 mm2, significantly larger in females. Conclusions: Massa intermedia is present in most of the investigated brains, usually connecting the anterior-superior quadrants of the lateral walls of the third ventricle. Different in shape and size its cross-section is a horizontal ellipse, significantly larger in females. The cross-sectional area and the size of the third ventricle are not in correlation

Comparison of the morphological parameters of the face in a population with a full dental arch

Introduction: The analysis of facial parameters in young people with a full dental arch is an assessment of the representation of certain anthropological features in the Serbian geographical area, but also a starting point for their reconstruction after tooth loss in order to achieve the maximum therapeutic and aesthetic effect. Aim: The aim of the work was to measure and compare facial parameters among respondents with a complete dental arch. Material and methods: 91 dental students participated in the research, 32 (35.2%) male and 59 (64.8%) female. The average age of the respondents was 22.16±1.53 years. The length and width of the face were measured, as well as the vertical and horizontal parameters, and the facial index was calculated. Results: Men had a significantly longer (Z=4.567; p<0.001) and wider face (Z=5.962; p<0.001) compared to women. There was no significant difference in the face index between women and men (ch 2 =2.492; p=0.666). There was also no significant difference in the vertical analysis of the face according to gender (ch 2 =0.065; p=0.798). In the majority of subjects, the shorter middle third of the face was measured. In the case of the expected division of the lower third of the face, it exists in a significantly greater extent in males (ch 2 =5.989; p=0.014). In the majority of subjects, the intercanthal width corresponded to the width of the eye, in both sexes, without statistical significance. Further, in a significantly larger number of male and female respondents, it was determined that the bipupillary corresponds to the intercommissural distance. The interalar distance corresponding to the width of the eye was more significantly present in women (ch 2 =5.002; p=0.025). Conclusion: Measurement of facial parameters can significantly improve dental therapy by enabling optimal aesthetic performance

Anthropometric parameters and aesthetics in the making of fixed prosthodontic restaurations: Part 2

Introduction: The role of aesthetic dentistry in the field of fixed dental prosthetics is to redesign the smile, which means not only the treatment on the teeth, but also the treatment of the surrounding soft tissues. Successful therapy can be achieved by establishing the harmony between the static (teeth, gingiva) and dynamic factors (lips, cheeks, mimic muscles) at rest and when performing various functions of the orofacial system. The aim: of the study was to analyze the parameters of the oral soft tissues (gingival health, gingival height, gingival zeniths, lip line and symmetry and balance of the dentition) that affect the aesthetics of fixed prosthodontic restorations. Literature data and clinical experience were used. Conclusion: Adherence to the described parameters is of great importance in the development of aesthetic and functional fixed prosthetic restoration

Removal of cationic pollutants from water by xanthated corn cob: optimization, kinetics, thermodynamics, and prediction of purification process

The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second order and Chrastil’s model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g-1 for Cr(III) ions and MB, respectively was obtained at 40 °C, pH 5 and sorbent dose 4 g dm-3 for removal of Cr(III) ions and 1 g dm-3 for removal of MB. The prediction of purification process was successfully carried out and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e. after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm-3. Also, removal of MB from the river water was successfully carried out and after 40 min removal efficiency was about 94 %