102 research outputs found
Grain size distribution of the YBa_2Cu_3O_7-x high temperature superconducting compound
The grain size distributions of three YBa_2Cu_3O_7-x ceramic samples, annealed at 960Ā° C for different times (t=7, 70 and 700 hours, respectively), have been investigated. Both the average grain size (r) and that in the longest dimension of the grain (l) have been measured. The ratio l/r (reflecting the deviation from the spherical shape) initially increases with the annealing time (t) but tends to decrease at elevated t. An approximate t^1/2 increase of l probably reflects a plate-like shape of grains. For all samples the distributions of r and l are fitted best with the log-normal (Gauss) grain size distribution. The correlation between the grain size and critical current distributions is briefly discussed
Formation and Aging Precipitates. Study on Nucleation of Strontium Sulfate from Solution
The rate of precipitation of strontium sulfate from aqueous
solutions was traced simultaneously by measurement of relative
intensity of light scattering as well as by direct observation of
particles by means of electron microscopy. Mechanisms for
ionic crystal growth from solution were discussed and compared
with experimental resulting precipitation rates. When the precipitate
is formed by direct mixing of ions the nucleation occurs
very rapidly. After the induction period the particles grow continuously,
but a distinct crystal structure began to appear in particles
whose length was bigger than 0.02 Ī¼m
Regulacija rasta i diferencijacije embrija sisavaca faktorima rasta FGF i NGF u kulturi organa in vitro
The aim was to analyze the regulation of growth and tissue differentiation in a unique in vitro4culture model of gastrulating mammalian embryo by fibroblast growth factor (FGF) and nerve growth factor (NGF) during two weeks. They both play a crucial role during embryogenesis and the purpose of this study was to test their possible synergistic influence in the period when mammalian embryos are extremely sensitive to external factors. We cultivated 9.5-day-old rat embryos on metal grid supported lens paper, at the air-liquid interface in culture medium (Eagle\u27s minimal essential medium (MEM) with 50% of homologous serum) with the addition of FGF, NGF and a combination of FGF/NGF in a time frame of 9 days. Other three groups of embryos were for 24 hours pretreated with 5-azacytidine (5azaC), an agent that can activate repressed genes. A parallel group of nontreated control embryos were cultivated with each experimental group. During 14 days of culture embryos grown in teratoma-like explants and growth rate were evaluated by measuring average size of explants using an eyepiece micrometer on days 5, 7, 11 and 14 after the addition of growth factors. Differences between respective groups were estimated by Student\u27s t-test. Differentiated tissues were estimated on serial histologic sections. c2-test or Fisher exact test were used to compare the proportion of tissues between respective groups. In embryo-derived teratomas NGF or FGF/ NGF combination used within the 9 day time frame did not stimulate differentiation of any kind of tissues; moreover, FGF/NGF inhibited maturation of epidermis, while FGF stimulated differentiation of neural tissue, hemopoiesis and myotubes. We did not observe any kind of stimulative cooperative action of FGF and NGF in differentiation processes. So it seems that NGF hinders the stimulating effect of FGF. NGF alone impaired growth of explants, but in combination with FGF acted synergistically, thus improving the growth rate of cultivated embryos. Additional activation of genes with 5azaC had no the effect on possible NGF influence on neural tissue differentiation, but resulted in improved myotube differentiation. The activation of genes with 5azaC/FGF signal and 5azaC/FGF/NGF combination improved the proportion of neural tissue and myotubes as well as hemopoiesis. Obviously, these results supported the role of FGF as neural inducer and mesoderm inducer. Anyway, FGF or NGF induced differentiation at least partially depends on the status of gene methylation.Namjera je bila istražiti regulaciju rasta i diferencijacije pomoÄu fibroblastnog faktora rasta (FGF) i faktora rasta živaca (NGF) u jedinstvenom in vitro modelu za kultiviranje embrija sisavaca u kritiÄnoj fazi razvoja, gastrulaciji, tijekom dva tjedna. Oba faktora imaju kljuÄnu ulogu u embriogenezi sisavaca, a svrha je bila istražiti njihov moguÄi sinergistiÄni uÄinak kada su embriji sisavaca najosjetljiviji na djelovanje pojedinih vanjskih Äimbenika. Embrije Å”takora stare 9,5 dana kultivirali smo na metalnoj mrežici s leÄnim papiriÄem, na granici plinske i tekuÄe faze, u temeljnom mediju za kultiviranje (Eagleovom minimalnom esencijalnom mediju (MEM) s 50% homolognog seruma) uz dodatak faktora rasta FGF, NGF i kombinacije FGF/NGF tijekom 9 dana kulture. Druge tri skupine embrija su prethodno bile tretirane 24 sata 5-azacitidinom (5azaC), agensom koji može aktivirati gene. Paralelne skupine embrija kultivirane su u temeljnom mediju kao kontrolne. Tijekom 14 dana kultiviranja embriji izrastu u teratoidne strukture, a pritom se rast procjenjuje odreÄivanjem prosjeÄene veliÄine eksplantata pomoÄu okularnog mikrometra u odreÄene dane (5, 7, 11, 14) nakon dodavanja faktora rasta. Razlike u rastu izmeÄu pojedinih skupina ispitane su Studentovim t-testom. Prisutnost diferenciranih tkiva u teratomima utvrÄena je analizom na serijskim histoloÅ”kim rezovima. Razlike u proporcijama diferenciranih tkiva izmeÄu pojedinih skupina utvrÄene su c2-testom ili Fisherovim egzaktnim testom. U embrijskim teratomima razvijenim in vitro niti NGF niti FGF/NGF kombinirani tretman nisu stimulirali diferencijaciju bilo koje vrste tkiva, dapaÄe, FGF/NGF kombinacija je inhibirala sazrijevanje epidermisa. FGF je stimulirao diferencijaciju živÄanog tkiva (p<0,05), miotuba i hemopoezu. Nismo mogli utvrditi sinergistiÄni uÄinak FGF i NGF u procesu diferencijacije bilo koje vrste tkiva. DapaÄe, Äini se da NGF smanjuje stimulacijski uÄinak FGF u procesu diferencijacije. NGF suzbija rast eksplantata, ali u kombinaciji s FGF djeluje sinergistiÄno, znaÄajno poveÄavajuÄi rast eksplantata. NGF nije imao uÄinka na oÄekivano poveÄanje diferencijacije živÄanog tkiva, nakon dodatne aktivacije gena pomoÄu 5azaC, meÄutim, diferencijacija miotuba je znaÄajno poveÄana. Kombinirano djelovanje 5azaC/FGF i 5azaC/FGF/NGF na aktivnost gena poveÄalo je uÄestalost diferencijacije živÄanog tkiva, miotuba i hemopoezu u eksplantatima. Ovaj rezultat potvrÄuje djelovanje FGF kao induktora živÄanog tkiva i mezoderma. U svakom sluÄaju diferencijacija potaknuta FGF i NGF signalima djelomice ovisi o stupnju metilacije gena
Civil Servantsā View of the Development of e-Government in Slovenia
The paper presents the results of a study focused on the so-called internal aspect of e-government ā i. e., the aspect of the civil servants. It is wellknown that in both Slovenia and most other countries there is a significant discrepancy between the selection and the actual use of the possibilities that e-government provides. A substantial number of researchers have been intensely engaged in the study of factors inciting (mainly) the citizens to use e-government. In our belief, those factors need also be searched for within the internal e-government users, i.e. the civil servants. In this perspective, we have examined: (1) their use of, and satisfaction with, information technologies in the job context; (2) their skills required for e-government; (3) the effect of e-government on their job, their organisation, and public administration in general; (4) their views of further development of e-government within the public administration. A number of results indicate that responsibility for the low use of e-government by citizens and enterprises can in fact be partly ascribed to the civil servants. Further, the research has revealed that the surveyed civil servants lacked sufficient skills required for an active participation in the development of e-government, and that this development has not resulted in any vital changes in the operations of the public administration
Churg-Straussov sindrom: prikaz sluÄaja
Churg-Strauss syndrome (CSS) is a necrotizing small vessel vasculitis characterized by the presence of asthma, hypereosinophilia and sinusitis. Other common manifestations are pulmonary infiltrates, skin, gastrointestinal and cardiovascular involvement. Although not a criterion for the diagnosis of CSS, the presence of antineutrophil cytoplasmic autoantibodies (ANCA) is now established as being associated with CSS. In this report, a 31-year-old male with a history of difficult-to-control asthma is presented. It was associated with peripheral and bronchoalveolar eosinophilia, sinusitis, and high level of ANCA (perinuclear labeling pattern). Clinical manifestations observed at the time of relapses were palpable purpura, erythema nodosum, arthralgia, musculoskeletal complications, and episcleritis. In spite of vasculitis remission, low doses of steroids to control asthma were necessary for 10 years. The aim of this case report is to point to the possibility of CSS in patients with severe persistent asthma and atypical allergic diathesis.Churg-Straussov sindrom (CSS) je granulomatozni vaskulitis posredovan antineutrofilnim citoplazmatskim autoantitijelima perinuklearne fluorescencije (P-ANCA). OÄituje se kliniÄkim simptomima ustrajne astme i sinusitisa uz izraženu eozinofiliju, Å”to kod progredirajuÄih oblika bolesti prethodi migrirajuÄim pluÄnim infiltratima uz izvanpluÄne pojavnosti na perifernim živcima, koži, srediÅ”njem živÄanom, probavnom i krvožilnom sustavu. Prikazujemo bolesnika s CSS koji se oÄitovao teÅ”kom ustrajnom astmom, perifernom i tkivnom eozinofilijom, sinusitisom i izrazito visokim titrom P-ANCA. Kontrola astme postignuta je tek nakon 10-godiÅ”nje steroidne terapije uz mnogobrojne nuspojave. Cilj prikaza je upozoriti na moguÄnost CSS kod težih oblika astme i ukazati na moguÄnost autoimunih pojavnosti u bolesnika s atopijskom konstitucijom
Trendi razvoja e-uprave v Sloveniji
Razvoj e-uprave, katere glavna cilja sta poveÄati uÄinkovitost in uspeÅ”nost poslovanja ter zagotoviti kakovostne in uporabnikom prijazne storitve, je v veÄini razvitejÅ”ih držav, pa tudi v Sloveniji, v polnem teku. Prispevek skuÅ”a predstaviti trende v razvoju e-uprave v Sloveniji s poudarkom na ponudbi storitev, upoÅ”tevajoÄ rezultate raziskav, ki jih na InÅ”titutu za informatizacijo uprave na Fakulteti za upravo opravljamo že od leta 1999
E-GOVERNMENT IN SLOVENIA: DOES SUPPLY MEET DEMAND OF CITIZENS?
Abstract The main objective of the paper is to explore how well the existing e-government supply in Slovenia meets the demand of its citizens. The research is based on the data gathered through several empirical studies. The look into the criteria with which the satisfaction with the use of e-government was assessed shows that the existing information is relatively useful yet incomplete and not very easily accessible. Furthermore, the criterion 'ease of access' was assessed as the worst in comparison to application forms and e-services. However, the supply-side survey shows that information is indeed dispersed over a wide range of websites; in order to find them the user should know in advance where to look. In contrast, the majority of application forms and e-services are accessible at one-entry-point leading to the significantly higher assessment of the above-mentioned criterion. Moreover, internet users consider the simplification of administrative procedures, simplification of e-services and one-stop-government as the most important factors (along with greater security) for future e-government development. This confirms again that e-government supply is not fully tailored to the needs and requests of its users. Chapter 1 Introduction Practically everyone has some dealings with the government during his/her life. Some people more, other less, depending on their life events or situations. Most of them use traditional or classic ways of interacting with the government: personal visits, regular post, telephone, but those who are adequately IT skilled also have the possibility to obtain particular information and services over the internet. In response to the increasingly sophisticated and comprehensive supply of government information and services online and the higher levels of internet penetration among people and businesses, the number of such users has also risen. However, the question is to what extent the existing e-government supply meets the demand of its users (existing and potential ones)? The answer is interesting from several points of view. The efforts and financial resources invested in developing e-services are to no avail if their users are not satisfied with them. On the other hand, taxpayers are also more and more interested in the return on investment in e-government. And last but not least, it has been known for some time that the development of e-government cannot be measured and evaluated on the basis of 1 Mateja Kunstelj and Anamarija Leben are assistants and Mirko Vintar is associate professor, all at the Faculty of Administration, University of Ljubljana, Sloveni
NeuroloÅ”ke manifestacije celijakije u odraslih: prikaz sluÄaja
Celiac disease is more common than previously thought, and a high index of suspicion is important in its diagnosis. Typically, cases of celiac disease present at the age of 5-24 months with the symptoms of intestinal malabsorption, growth retardation, abnormal stools, abdominal distension, muscle wasting, hypotonia, poor appetite and low spirit. In adults, the symptoms of celiac disease may be highly varied. The incidence of malignancies is also increased. Most of these are small bowel lymphomas and carcinomas of the esophagus and colon. In some patients, the disease is associated with clinical dysfunction of the nervous system, manifesting variably as encephalopathy, cerebellar abnormalities, seizures, cerebral atrophy and dementia, brain stem encephalitis, cerebral vasculitis, myopathy, quadriparesis (metabolic), myelopathy, peripheral neuropathy, multifocal leukoencephalopathy, and psychiatric disorders. Presentation is made of a 47-year-old woman with misdiagnosed celiac disease, who first developed pain in the back which was treated with spinal support. She also complained of very severe bone pains. Finally, she was admitted to the hospital with a history of increasing difficulty on walking, weakness in her legs, urine incontinence, and 5-kg weight loss in four months. Celiac disease should therefore be considered on differential diagnosis in patients presenting with unexplained neurologic symptoms.Celijakija je uÄestalija nego Å”to se misli i to treba uzeti u obzir pri diferencijalnoj dijagnostici nejasnih neuroloÅ”kih sindroma. ObiÄno se javlja u dobi od 5-24 mjeseca sa znacima crijevne malapsorpcije, zaostajanjem u rastu, nadutoÅ”Äu uz uÄestale stolice, slabost miÅ”iÄa, hipotoniju, slab apetit i neraspoloženje. U odraslih znaci celijakije mogu biti razliÄiti. UÄestalost malignoma takoÄer je poveÄana. U nekih je bolesnika celijakija povezana sa znacima oÅ”teÄenja živÄanoga sustava poput encefalopatije, cerebelarne simptomatologije, cerebralne atrofije, demencije, cerebralnog vaskulitisa, miopatije, oduzetosti ekstremiteta, periferne neuropatije, viÅ”ežariÅ”ne encefalopatije i psihijatrijskih poremeÄaja. Opisana je 47-godiÅ”nja bolesnica s nedijagnosticiranom celijakijom, u koje je prvi simptom bila intenzivna bol u leÄima, zbog koje je provodila fizikalnu rehabilitaciju. Nakon toga javili su se difuzni bolovi u kostima uz teÅ”koÄe pri hodu, a potom napredujuÄa slabost donjih ekstremiteta. Zbog flacidne parapareze, smetnji mokrenja i gubitka tjelesne težine bolesnica je primljena na bolniÄko lijeÄenje. Dakle, u bolesnika s nejasnom neuroloÅ”kom simptomatologijom treba u obzir uzeti i moguÄnost da se primarno radi o celijakiji
- ā¦