22 research outputs found
Prevalance study of glaucoma in Malta and Gozo
A glaucoma survey was carried out in Malta and Gozo. Using non-contact pulseair tonometer, 2245 participants selected on a random basis, aged 40 years and above, were examined and 3.29% were found to have glaucoma. Among them 1.69% were newly detected glaucoma cases. The main risk factors were diabetes mellitus in the personal past history and glaucoma in the family history. Age was confirmed to be a risk factor, but arterial hypertension and myopia could not be proved as risk factors. About 4000 glaucoma cases were estimated to be present in Malta and Gozo at the time of the survey. Some other ocular conditions were also found in relatively high percentages: cataract -3.3%, myopic maculopathy -2.9% and diabetic retinopathy -1.5%.peer-reviewe
Papillitis as the prominent ocular sign in Acquired Immune Deficiency Syndrome (AIDS)
A 29-year old homosexual presented with clinical symptoms and an immunological picture of AIDS syndrome. Ocular involvement started in August 1986 with reduction of visual acuity in the right eye rapidly progressing to amaurosis. The most prominent ophthalmoscopical sign was of papillitis which had, in the beginning, the characteristics of an ischaemic optic neuropathy. Besides this, cotton-wool spots, retinal haemorrhages and limited areas of Cytomegalovirus (CMV) retinitis were found. Choroid was also involved with secondary CMV retinitis. On the other hand, sheathing of retinal vessels and Roth’s spots were absent. Although papilloedema, haemorrhages, cotton-wool exudates and CMV retinitis completely disappeared by October 1986, the general condition aggravated and the patient finally succumbed.peer-reviewe
Ocular manifestations in lepromatous and tuberculoid leprosy
Ocular manifestations of leprosy in 100 patients examined were reported on; -80% were suffering from the lepromatous type of the disease. The most frequent change was loss of eyebrows (40%) which was seen mainly in lepromatous patients. The sclera and cornea were rarely affected separately, but sclerokerato-iridocyclitis was found in 3%. On the other hand, the iris was involved rather more often -16% (atrophy of the iris -4, atrophy of the pupillary margin -3, miosis -1, posterior synechiae -6, keratic precipitates -1, and iris "pearls" -1). The iritis always had an insidious chronic evolution. The origin of the iritis is probably multifactorial: a) neuroparalytic due to involvement of the autonomic nerves supplying the iris muscles, primarily dilator; b) direct effect of Mycobacterium leprae on the iris tissue; and c) immune or auto-immune mechanisms. The posterior uvea was rarely affected (2%). No case of primary glaucoma was detected, but secondary glaucoma due to sclerokerato-iridocyclitis was found in 2 cases. Cataract seems to occur more frequently in leprosy patients (20%) than in the general population. The anterior segment was mostly affected (21%), and all these cases belonged to the lepromatous (16) or borderline lepromatous (5) type.peer-reviewe
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
Analiza naponsko-deformacionog stanja vratila pogonskog bubnja
The paper presents an analysis ofthe stress deformation state o f shafts o f characteristic drive pulleys on belt conveyors in Drmno open pit mine. The shape and dimensions o f the shafts were defined based on the original technical documentation, and the stress state was verified by applying the finite difference method in the Catia software package. Loads were simulated for real working conditions in exploitation. The analysis results showed that shafts with cone between locking device and bearing have the best load distribution and that T-shaped end disks most favourably transfer loads to the shaft. The analyses also showed that the values o f stresses formed in shafts at the failure site are not high enough to lead to shaft failure due to overload and that failure cause should be sought in fatigue, then in plastic deformation, residual stresses after shaft repair and pulley weight unbalance.Publishe
Thermal stability of lubricants in cycloidal reducers
There is intensive rolling and sliding between the meshing elements of a cycloidal reducer, whereby a significant amount of mechanical energy is converted into heat and absorbed by the lubricant. In order to stabilize the temperature of the lubricant, it is necessary to achieve thermal equilibrium, i.e. the amount of heat dissipated should equal the amount of heat generated. A complex task of determining the equilibrium temperature of a lubricant generally involves theoretical analysis, numerical calculation, computational simulations and experimental testing. The aim of this paper is to develop a model to predict the amount of heat dissipated from the outer surface of the housing as well as the equilibrium temperature of the lubricant. The model is based on the basic laws of thermodynamics, while the computational simulation is performed for an actual cycloidal reducer in the Matlab software package. The simulation results show changes in the equilibrium temperature in relation to: the coefficient of heat transfer from the lubricant to the inner wall of the housing, ambient air velocity, wall thickness and housing material.Publishe
Modeling of thermoelectric module operation in inhomogeneous transient temperature field using finite element method
This paper is the result of research and operation modeling of the new systems for cooling of cutting tools based on thermoelectric module. A copper inlay with thermoelectric module on the back side was added to a standard turning tool for metal processing. For modeling and simulating the operation of thermoelectric module, finite element method was used as a method for successful solving the problems of inhomogeneous transient temperature field on the cutting tip of lathe knives. Developed mathematical model is implemented in the software package PAK-T through which numerical results are obtained. Experimental research was done in different conditions of thermoelectric module operation. Cooling of the hot module side was done by a heat exchanger based on fluid using automatic temperature regulator. After the calculation is done, numerical results are in good agreement with experimental. It can be concluded that developed mathe-matical model can be used successfully for modeling of cooling of cutting tools
Aerozagađenje polenom Ambrosia Artemisiifolia L. Na teritoriji grada Novog Sada
As important weed on agricultural areas, Ambrosia artemisiifolia L.
represents a great problem. This weed species is also recognized as significant
allergenic species, representing thus significant medical and economic problem. One
gram of Ambrosia artemisiifolia L. pollen contains 30-35 million of pollen grains, and
during the year, one plant can produce more than 45 grams (<1350 million) of pollen
grains. During 2014 pollination season, the amount of ragweed was measured at Faculty
of Agriculture. Measured pollen peaks showed that in m3 of the air there were 447
pollen grains.Izuzetan problem za poljoprivrednu proizvodnju predstavlja Ambrosia
artemisiifolia L., kao korov na poljoprivrednim površinama, ova korovska vrsta
prepoznata je i kao značajan alergen, a samim tim predstavlja medicinski i ekonomski
problem. Jedan gram polena Ambrosia artemisiifolia L. sadrži 30-35 miliona polenovih
zrna, a jedna biljka tokom godine može proizvesti više od 45 grama (<1350 miliona
polenovih zrna) polena. U sezoni polinacije, na Poljoprivrednom fakultetu je merena
količina polena ambrozije, tokom 2014. godine. Pik je izmereni krajem avgusta meseca
kada je taj broj bio 447 polenovih zrna u m3 vazduha
Genetic correlation between amyotrophic lateral sclerosis and schizophrenia
A. Palotie on työryhmän Schizophrenia Working Grp Psychiat jäsen.We have previously shown higher-than-expected rates of schizophrenia in relatives of patients with amyotrophic lateral sclerosis (ALS), suggesting an aetiological relationship between the diseases. Here, we investigate the genetic relationship between ALS and schizophrenia using genome-wide association study data from over 100,000 unique individuals. Using linkage disequilibrium score regression, we estimate the genetic correlation between ALS and schizophrenia to be 14.3% (7.05-21.6; P = 1 x 10(-4)) with schizophrenia polygenic risk scores explaining up to 0.12% of the variance in ALS (P = 8.4 x 10(-7)). A modest increase in comorbidity of ALS and schizophrenia is expected given these findings (odds ratio 1.08-1.26) but this would require very large studies to observe epidemiologically. We identify five potential novel ALS-associated loci using conditional false discovery rate analysis. It is likely that shared neurobiological mechanisms between these two disorders will engender novel hypotheses in future preclinical and clinical studies.Peer reviewe