Age-Related Skeletal Muscle Atrophy in Humans: An Immunohistochemical and Morphometric Study

The aim of this study was to determine age-related changes in three human muscles with different function and location in the body. The cross sectional area and the percentage of fibers type I, type IIA and type IIX were studied in vastus lateralis, deltoideus and external intercostal muscle. Muscle samples were obtained from 30 male subjects, aged 20–80 years. Fiber types were defined immunohistochemically, using monoclonal antibodies specific for type I, type IIA and type IIX fibers. Cross sectional area of muscle fibers was analyzed morphometrically by computerized image analysis. All muscle fiber types (I, IIA, IIX) showed the reduction in the fiber size in all three examined muscles. In all muscles the proportion of type I and type IIA was changed, but not in type IIX. With increasing age results showed the increase in proportion of type I, while proportion of type IIA fibers decreased, with vastus lateralis muscle being the most affected. These results suggest that age-related muscle atrophy is not a general phenomenon, and does not affect all muscles equally

ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF THE MUZZLE BRAKE EFFICIENCY

The muzzle brake efficiency was investigated both analytically and experimentally in this paper. An experimental test system was developed to measure the recoil force of a 12.7 mm anti-material rifle. Two types of the muzzle brake were used. The recoil force with and without muzzle brake and the muzzle velocity of the projectile were recorded. Then the muzzle brake efficiency was calculated. Besides, an analytical model based on the Orlov method for calculating muzzle brake efficiency was adopted. The obtained results were discussed. The maximum of the muzzle brake force, projectile velocity and muzzle brake efficiency obtained experimentally and analytically were compared. The analytical results were in a good agreement with the experimental ones

HEADACHES IN CHILDREN

Uvod: Glavobolja je vrlo čest simptom u djece i adolescenata, a uzroci su raznoliki. Cilj: Raščlaniti i povezati anamnestičke podatke i nalaze djece hospitalizirane na Neuropedijatrijskom odjelu s dijagnozom glavobolje pri prijmu - povezati trajanje, kliničku sliku i uzroke glavobolja; oblik glavobolje klasificirati prema kriterijima The International Classification of Headache Disordersa, 2nd Edition. Metode: Retrospektivna analiza kliničkih značajki glavobolja u 377-ero djece praćene u razdoblju od 1. 1. 2003. Do 31. 12. 2007. Rezultati: Analiza obuhvaća podatke 221 (58.6%) djevojčice i 156 (41.4%) dječaka. Srednja dob ispitanika bila je 11godina i 8 mjeseci (raspon 2 godine i 8 mjeseci – 22 g.). Trajanje glavobolje ≤3 mj. Bilo je prisutno u 137-ero (36.3%) djece, u njih 220-ero (58.4%) >3mj, a u 20-ero (5.3%) djece podatci su bili nepoznati. Akutna glavobolja bila je prisutna u 144-ero (38.2%) djece, a recidivirajuća u njih 215-ero (57.0%). U sve djece učinjena je hematološko-biokemijsko-mikrobiološka, neurološka, okulistička i ORL obrada. Na temelju anamneze i ostalih nalaza glavobolje smo klasificirali kao: tenzijske (36.1%), moguće tenzijske (5.6%), povezane sa strukturnim promjenama organa glave (20.7%), migrena (16.7%), posttraumatske(3.2%), intrakranijske nevaskularne (neoplazme, disfunkcija drenažnog sustava prema Pudenzu) (1.8%) i vaskularne (CVI ) (0,3%). Učestalost glavobolja povezanih s infekcijom (sistemske infekcije, nakon preboljelog meningitisa) nađena je u 0.8% , zbog hipertenzije 0.5% slučajeva, dok su ostali uzroci (neklasificirane, sideropenična anemija, multipla skleroza, epilepsija, menstruacija) bili prisutni u 14.3% djece. Zaključak: Najčešći tip glavobolje bile su psihogene – tenzijske glavobolje.Radi utvrđivanja etiološke dijagnoze glavobolja koje zahtijevaju specifičnu terapiju, preporučujemo detaljnu kliničku obradu djece kojoj glavobolja traje dulje od tri mjeseca.Introduction: Headache is a common symptom in children and adolescents, with various causes. AIM: To divide and put together the anamnestic data and findings of children hospitalized at the Neuropaediatric Unit with headache as the primary diagnosis – to associate the duration, clinical features and causes of headaches and classify them according to the criteria of The International Classification of Headache Disorders Second Edition. Methods: The retrospective analysis of clinical data in 377 children followed up from January 1st 2003 until December 31st 2007. Results: The analysis includes data from 221(58.6%) girls and 156 (41.4%) boys. Mean age was 11 years (y) and 8 months (m) (2y8m – 22y). Headache with duration ≤3m was found in 137 (36.3%), >3m in 220 (58.4%) children. In 20 (5.3%) children the data was unknown. Acute headache was present in 144 (38.2%), recurrent headache in 215 (57.0%) children. In all children the haematological-biochemical-microbiological findings were made, together with neurological, ophthalmologic and ORL evaluation. Based on anamnestic data and findings we classified headaches as follows: tension-type (36.1%), possible tension-type (5.6%), associated with structural changes of the organs in the head (20.7%), migraine (16.7%), post-traumatic (3.2%), intracranial non-vascular (neoplasms, dysfunction of Pudenz drainage system) (1.8%) and vascular (CVI) (0,3%). Frequency of headaches associated with infection (systemic infection, after meningitis) was 0.8%, headache 0.5% was due to hypertension, while other causes were noted in 14.3% (non-classified, sideropenic anaemia, multiple sclerosis, epilepsy, menstruation). Conclusion: The most frequent type of headache was tension-type headache. In order to evaluate the etiological diagnosis of headaches which demand specific therapy, we recommend detailed clinical evaluation in children with duration of headaches of more than 3 months

GISAXS/GIXRD View of ZnO Films with Hierarchical Structural Elements

ZnO films constituted of porous sheet-like structures, formed by calcination of precursor, were examined using scanning electron microscopy and simultaneous small-angle scattering and diffraction of the synchrotron-sourced X-rays, under the grazing-incidence conditions. The presented analysis enabled insight into the complexity of the film morphology, which revealed substrate sensitivity on the microscopic and nanoscopic length scales. The average size and spatial arrangement of nanoparticles, single-crystal domains, and the average size and features of nanopores in sheet-like structures were determined for films deposited on glass, polycrystalline ZnO layer, and silicon

Comparison of Static Aerodynamic Data Obtained in Dynamic Wind Tunnel Tests and Numerical Simulation Research

The aerodynamic data obtained in the static and dynamic wind tunnel tests are presented in this paper. The tests are performed in the T-38 wind tunnel facility of the Military Technical Institute in Belgrade. Normal force and pitching moment in static and dynamic tests are measured using semiconductor five-component strain gauge balance. This specific five-component balance is dynamic derivative balance. Forced oscillation technique is used for the dynamic measurements applied in the T-38 wind tunnel. The wind tunnel data are compared with aerodynamic data determined using flow simulations with RANS (CFD) code and applied models of turbulence. The aerodynamic data calculated using semi-empirical prediction were the initial values for the numerical research. The experimental and numerical data are presented for the one standard missile model (Modified Basic Finner Model) for three flow regime Mach numbers

Functional dissection of the Sox9-Kcnj2 locus identifies nonessential and instructive roles of TAD architecture

The genome is organized in three-dimensional units called topologically associating domains (TADs), through a process dependent on the cooperative action of cohesin and the DNA-binding factor CTCF. Genomic rearrangements of TADs have been shown to cause gene misexpression and disease, but genome-wide depletion of CTCF has no drastic effects on transcription. Here, we investigate TAD function in vivo in mouse limb buds at the Sox9-Kcnj2 locus. We show that the removal of all major CTCF sites at the boundary and within the TAD resulted in a fusion of neighboring TADs, without major effects on gene expression. Gene misexpression and disease phenotypes, however, were achieved by redirecting regulatory activity through inversions and/or the repositioning of boundaries. Thus, TAD structures provide robustness and precision but are not essential for developmental gene regulation. Aberrant disease-related gene activation is not induced by a mere loss of insulation but requires CTCF-dependent redirection of enhancer-promoter contacts

Mineral and volatile composition of agua-mel from Portugal

Agua-mel (honey-water) is a typical honey-based product produced by the Portuguese beekeepers, particularly in southern Portugal. Agua-mel was characterized by mineral content and volatiles contents. Mineral content evaluation was performed based on a random sampling of 14 samples from a total of 16 samples provided by local producers. Mineral content showed that potassium predominated in agua-mel samples (1270-4105 mg/kg). The concentration of aluminium in one sample was tenfold higher (5.8 mg/kg) than in the remaining samples (0.3-0.6 mg/kg). Agua-mel volatiles were isolated by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) from a subset of eight samples. Cluster analysis showed two poorly correlated clusters (S (corr) < 0.3). Cluster I only sample was dominated by trans-beta-ocimene (19 %), gamma-terpinene (15 %) and 2-furfural (9 %). Cluster II that included the remaining seven samples showed two moderately correlated subclusters (S (corr) < 0.5). The six samples with high correlation from subcluster IIa were dominated by 2-furfural (18-41 %) and benzene acetaldehyde (12-39 %). n-Nonadecane (14 %), n-heneicosane and 2-furfural (both 13 %) were the main components of subcluster IIb sample. Although the presence of some volatile compounds can help in the correlation between agua-mel and honey botanical source, the final product varies largely according to the preparation process even for the same producer, in different years. Agua-mel detailed characterization may assist in bringing added value to this typical Portuguese honey-based product

The influence of aerodynamic coefficients on the elements of classic projectile paths

The article deals with the results of the research on the influence of aerodynamic coefficient values on the trajectory elements and the stability parameters of classic axisymmetric projectiles. It presents the characteristic functions of aerodynamic coefficients with regard to aerodynamic parameters and the projectile body shape. The trajectory elements of the model of classic axisymmetric projectiles and the analyses of their changes were presented with respect to the aerodynamic coefficient values. Introduction Classic axisymmetric projectiles fly through atmosphere using muzzle velocity as initial energy resource, so the aerodynamic force and moment have the most significant influence on the motion of projectiles. The aerodynamic force and moment components represented as aerodynamic coefficients depend on motion velocity i. e. flow velocity, the flow features produced by projectile shape and position in the flow, and angular velocity (rate) of the body. The functional dependence of aerodynamic coefficients on certain influential parameters, such as angle of attack and angular velocity components is expressed by the derivative of aerodynamic coefficients. The determination of aerodynamic coefficients and derivatives enables complete definition of the aerodynamic force and moment acting on the classic projectile. The projectile motion problem is considered in relation to defining the projectile stability parameters and the conditions under which the stability occurs. The comparative analyses of aerodynamic coefficient values obtained by numerical methods, semi empirical calculations and experimental research give preliminary evaluation of the quality of the determined values. The flight simulation of the motion of a classic axisymetric projectile, which has the shape defined by the aerodynamic coefficient values, enables the comparative analyses of the trajectory elements and stability characteristics. The model of the classic projectile flight The velocity of the projectile flight in relation to the Earth represents the relative velocity, and the time derivatives of the velocity projections to coordinate frame axis represent the relative acceleration components. The mass of classic axisymetric projectile is constant during the flight, because there is no mass change caused by the rocket engine. The values of components of aerodynamic force and moment depend on the angle of attack being the basic parameter. The projections of the total aerodynamic force, because of the nature of its effect on the projectile, are given in an aeroballistics coordinate frame with the coordinate origin positioned in the center of gravity. The determination of aerodynamic coefficients with respect to projectile construction, i. e. the projectile geometry, is based on the theoretical approach of fluid mechanic equation and it leads to numerical solving of the partial differential equation system with the given boundary conditions and experimental results of tunnel research, i. e. measured flight parameters. In this part of the article, the aim is to describe the functions of dependence of aerodynamic coefficients on given parameters. Flight simulation of the classic projectile The determination of aerodynamic coefficients, i. e. the determination of the motion trajectory elements and stability parameters according to the model of six degrees of freedom, is done on the classic 40mm axisymmetric projectile model, the shape of which is based on the geometric characteristics of the front ogive part and the back cone with the flat bottom. The equations of the model of six degrees of freedom are given in the aeroballistics coordinate frame. The initial data in the simulation are given for the values of aerodynamic coefficients and derivatives obtained by the calculations and experiments. The analysis of the change of trajectory elements and stability characteristics is done with respect to two given kinds of aerodynamic characteristics. The analysis of the trajectory element change and stability characteristics is also done in relation to the possible discrepancy of the values of aerodynamic coefficients and derivatives. The possible discrepancies are given in accordance with the analysis of the values of aerodynamic coefficients obtained by the calculation and experiment. The influence of aerodynamic coefficients on the classic projectile motion analysis The individual analysis of the influence of aerodynamic coefficients on the motion trajectory key elements and stability characteristics is done. The influence of axial aerodynamic coefficients, normal and side force derivatives, as well as the influence of the pitching, yawing and rolling moment derivatives, is considered. The most important influences of each of the components of aerodynamic coefficients are given and the values of the trajectory elements discrepancies are determined - of range, velocity, angular velocity, derivation, angle of attack and angle of yawing, i. e. stability characteristics - of dynamic and gyroscope stability factors and stability equation coefficients. Conclusion The need for a proper description of aerodynamic coefficients, in physical and mathematical sense, is a precondition of their adequate and reliable calculation. The highest values of aerodynamic coefficients, according to the calculation result analysis, are those of axial force coefficients, normal force and pitching moment, which means that they have the greatest influence on the overall aerodynamic resistance during the projectile motion. The influences of other aerodynamic coefficients are quantitatively lesser, but not insignificant, because they influence directly on the motion stability parameters. The character of the position change of the point of attack is almost the same according to experimental and calculation results. The trajectory elements of the model projectile for aerodynamic coefficients determined by calculation and experiment show considerable compliance in the flight simulation in a computer program with six degrees of freedom in a wide range of initial angles. The difference in values of calculation and experimental values of aerodynamic coefficients demonstrated the difference in the values of the obtained trajectory elements, and particularly in stability parameters. Dynamic derivatives of aerodynamic coefficients (stability derivatives) have great influence on stability motion parameters. Experimental measurement of derivatives of aerodynamic coefficients is very complex and expensive because it entails the use of gauges for each of the derivatives. The importance of improvement of existing calculations and the development of new numerical solutions is evident in the reduction of the experimental research expenses