142 research outputs found
New integrability conditions of derivation equations in a subspace of asymmetric affine connection space
Variability of Photosynthetic Parameters Inselected Wheat (Triticum Aestivum L.)Varieties
The aim of this study was to explain the genetic variability of seven varieties of wheat (Triticum aestivum L.) and two varieties of triticale (hybrid wheat x rye) at unfertilized soil.The investigations included pigments content, leaf area, nitrogen content in the leaf, leaf and mesophyll thickness.Obtained results showed that there is a clear genetic variability in all tested components. Per study values for yield especially the prominent Lazarica genotype and both varieties hybrid species triticale – KG 20 and Knjaz,which also had the highest values for most parameters of productivity.Therefore, these genotypes of wheat can be recommend for organic production
Finite Size Scaling in Asymmetric Systems of Percolating Sticks
We investigate finite size scaling in percolating widthless stick systems with variable aspect ratios in an extensive Monte Carlo simulation study. A generalized scaling function is introduced to describe the scaling behavior of the percolation distribution moments and probability at the percolation threshold. We show that the prefactors in the generalized scaling function depend on the system aspect ratio and exhibit features that are generic to whole class of the percolating systems. In particular, we demonstrate existence of characteristic aspect ratio for which percolation probability at the threshold is scale invariant and definite parity of the prefactors in generalized scaling function for the first two percolation probability moments
Tracheotomy in children
IntroductionTracheotomy is one of the most urgent procedures in medicine. It is an operative procedure that creates a surgical airway in the cervical trachea.AimTracheostomy refers to a surgical incision made into a trachea. Children are often considered “little people”, however, in medical sense, that is not completely true. The aim of our paper is to review the tracheostomy procedure in children.Materials and MethodsIn this paper, we analysed the tracheostomies in children performed in the Clinical Centre Niš (Serbia) in the five-year period from January 2015 to December 2019 inclusive. At our centre, all tracheostomies were solely performed by otolaryngologists.ResultsA total of 37 tracheotomies were performed in the studied period. There were 25 (67.6%) boys and 12 girls (32.4%). The main reason for this relatively low tracheostomy count in our study is because our practitioners are usually performing tracheostomies only in children that require urgent care. All chronic or complicated cases, if they are stable enough to transport, are referred to a higher specialised institution in Belgrade, Serbia.The youngest was a newborn, not older than 1 hour, and the oldest was 17 years old. We divided them into groups according to the age. There were 5 (13.5%) neonates, 25 (67.6%) infants, 3 (8.1%) preschoolers, 2 (5.4%) school-aged children, and 2 (5.4%) adolescents. This is in concurrence with other studies, where authors reported that the highest number of tracheostomies (around 65–70%) were performed before 1 year of age.In most cases, indication for tracheostomies were upper airway obstructions (n = 35, 94.6%). Prolonged orotracheal intubation (n = 1, 2.7%), and protective tracheostomy (n = 1, 2.7%) were the causes in the other two cases.ConclusionWhile researching the literature for this paper we found that there is little standardisation associated with tracheostomy, even though it is a procedure that is performed regularly all over the globe. There is evidence that there is a disparity in opinions not only among the practitioners in different countries, but in individual countries as well. With the increasing number of patients that require tracheostomy, we find that this topic should be addressed more carefully with the attempt to establish the best way of action for this procedure, and with that, lower the complication and mortality rates
Characteristics of Germination and Biomass Production of Ocimum Basilicum L. Cultured In Vitro
The aim of this study was to investigate impact of nutrient medium on sweet basil (Ocimum basilicum L.) in vitro germination, early growth and biomass acumulation. Two different nutrient media (MS and B5 full and half of strait), most commonly used in tissue culture, demonstrated different impact on sweet basil. According to the results, B5 medium significantly outperformed all other media used in this study. We suggest that B5 medium are better for a variety of uses in sweet basil biotechnology, research and production system
Količina fenolnih jedinjenja i antioksidativna aktivnost odabranih vrsta roda Teucrium
The quantity of phenolic compounds, concentration of flavonoids and antioxidant activity were analysed by menas of speectrophotometric methods in methanol, ethanol, acetate and ethyl acetate extract of the species Teucrium fruticans L., T. flavum L. and T. chamaedrys L. (Lamiaceae). The total quantity of phenolic compounds ranged from 45,91 to 271,47 mg GA/g of extract. The concentration of flavonoids varied from 40,56 to 123,64 mg Ru/g of extract. The greatest quantity of phenolic compounds was measured in the methanol extract of the species T. chamaedrys, whereas the highest concentration of flavonoids was found in the acetone extract of the species T. fruticans. The antioxidant activity was within the range of values between 129,33 and 6,45 µg/ml. The highest antioxidant activity was observed in the methanol extract of the species T. chamaedrys, the one in which the greatest quantity of phenolic compounds was found as well.Količina fenolnih jedinjenja, flavonoida kao i antioksidativna aktivnost analizirani su u metanolnim, etanolnim, acetonskim i etil acetatnim ekstraktima biljnih vrsta Teucrium fruticans L., T. flavum L. i T. chamaedrys L. (Lamiaceae). Količina ukupnih fenolnih jedinjenja je u opsegu od 45,91 do 271,47 mg GA/g ekstrakta. Količina flavonoida je u opsegu od 40,56 do 123,64 mg RU/g ekstrakta. Najveća količina ukupnih fenolnih jedinjenja izmerena je u metanolnom ekstraktu vrste T. chamaedrys, dok je najveća količina flavonoida izmerena u acetonskom ekstraktu vrste T. fruticans. Antioksidativna aktivnost je od 129,33 do 6,45 µg/ml. Najvišu antioksidativnu aktivnost ispoljava metanolni ekstrakt vrste T. chamaedrys
A novel framework for fluid/structure interaction in rapid subjectspecific simulations of blood flow in coronary artery bifurcations
Background/Aim. Practical difficulties, particularly long model development time, have limited the types and applicability of computational fluid dynamics simulations in numerical modeling of blood flow in serial manner. In these simulations, the most revealing flow parameters are the endothelial shear stress distribution and oscillatory shear index. The aim of this study was analyze their role in the diagnosis of the occurrence and prognosis of plaque development in coronary artery bifurcations. Methods. We developed a novel modeling technique for rapid cardiovascular hemodynamic simulations taking into account interactions between fluid domain (blood) and solid domain (artery wall). Two numerical models that represent the observed subdomains of an arbitrary patient-specific coronary artery bifurcation were created using multi-slice computed tomography (MSCT) coronagraphy and ultrasound measurements of blood velocity. Coronary flow using an in-house finite element solver PAK-FS was solved. Results. Overall behavior of coronary artery bifurcation during one cardiac cycle is described by: velocity, pressure, endothelial shear stress, oscillatory shear index, stress in arterial wall and nodal displacements. The places where (a) endothelial shear stress is less than 1.5, and (b) oscillatory shear index is very small (close or equal to 0) are prone to plaque genesis. Conclusion. Finite element simulation of fluid-structure interaction was used to investigate patient-specific flow dynamics and wall mechanics at coronary artery bifurcations. Simulation model revealed that lateral walls of the main branch and lateral walls distal to the carina are exposed to low endothelial shear stress which is a predilection site for development of atherosclerosis. This conclusion is confirmed by the low values of oscillatory shear index in those places
Bases farmacológicas del uso de Acorus calamus L. en enfermedades inflamatorias y las vías de transducción de señales subyacentes
Acorus calamus L. se utiliza como remedio anti-inflamatorio en el sistema tradicional de la medicina en Pakistán y la India. Este estudio fue diseñado para explorar el mecanismo anti-inflamatorio de Acorus calamus L. y sus vías de señalización subyacentes. Fracciones acuosa, butanólica y de n-hexano de Acorus calamus se ensayaron frente a la ciclooxigenasa (COX) y de la lipoxigenasa (LOX) mediada por la producción de eicosanoides por el ácido araquidónico (AA). La fracción butanólica de Acorus calamus, pero no las fracciones acuosas y de n-hexano, inhibieron la producción de COX mediada por tromboxano B2 (TXB2) y el producto lipoxigenasa 1 (LP1) - un metabolito de la vía de LOX, 12 - (ácido hidroxieicosatetraenoico) HETE - otro producto de la ruta de LOX no fue afectado por las tres fracciones. La fracción butanólica de Acorus calamus mostró una fuerte inhibición contra la agregación plaquetaria inducida por AA. La investigación de las vías de señalización subyacentes reveló que la fracción butanólica inhibió la fosfolipasa C (PLC) y la vía en las plaquetas, probablemente actuando sobre la proteína quinasa C (PKC). Fracciones acuosas y de n - hexano de Acorus calamus no fueron eficaces contra ningún agonista de plaquetas. Este estudio muestra que la fracción butanólica de Acorus calamus posee componentes que inhiben el metabolismo del AA y la agregación plaquetaria a través de múltiples vías
Mogućnost zamene ribljeg brašna sojinim koncentratom u ishrani pastrmke
U uslovima intenzivnog gajenja kalifornijske pastrmke (Oncorhynchus mykiss), troškovi ishrane čine 50 do 70% ukupnih troškova u proizvodnji. Tokom višegodišnjih istraživanja, došlo se do zaključaka da proteinska hraniva biljnog porekla u određenoj meri mogu da zamene riblje brašno (FM) i smanje troškove proizvodnje. Najčešće korišćeni biljni proteini u ishrani riba su sojini proizvodi. Međutim, uspešnost zamene ribljeg brašna zavisi od vrste ribe koja se gaji, uzrasta riba kao i tipa korišćenog sojinog proizvoda. Kao jedan od boljih alternativnih izvora proteina navodi se sojin proteinski koncretat (SPC). SPC se dobija ekstrakcijom proteina iz sojinog brašna i sadrži oko 70% proteina. U akvakulturi predstavlja dobru zamenu za riblje brašno, jer sadržaj i svarljivost proteina u SPC su slični kao u FM. Neutralnog je ukusa i standardno je dobrog kvaliteta u odnosu na promenljiv kvalitet FM.
Istraživanje je sprovedeno u „Centru za ribarstvo i primenjenu hidrobiologiju“ ODPF Radmilovac. Mlađ kalifornijske pastrmke, prosečne nasadne mase 33,62g, hranjena je smešama koncentrata (44/20 Extra, proizvođača Veterinarski zavod Subotica) sa različitim procentualnim učešćem FM:SPC, i to: 100:0, 75:25, 50:50, 25:75 i 0:100.
Na osnovu dobijenih rezultata, nakon 60 dana hranjenja riba smešama koncentrata sa različitim učešćem FM i SPC, mogu se konstatovati statistički vrlo značajne razlike u masi i dužini tela. Najbolju završnu masu, kao i BWG, SGR, TGC i FER uz najmanji FCR imale su ribe hranjene smešom gde je odnos FM:SPC bio 75:25. Nasuprot tome, ribe hranjene smešom koncentrata bez učešća FM, imale su statistički vrlo značajno niže vrednosti BWG, SGR, TGC i FER, pri čemu je FCR bio statistički vrlo značajno veći nego upotrebom drugih smeša.
Dobijeni rezultati ukazuju da je u ishrani mlađi kalifornijske pastrmke najopravdanije koristiti smešu u kojoj je odnos FM:SPC bio 75:25, kako zbog proizvodnih rezultata tako i zbog smanjenja cene koštanja samog proizvoda
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