330 research outputs found
The Past, the Present and the Future of Nanotechnologies
Artists from the time of Mesopotamia or Egypt and in the Middle Ages astonished us with various coloured Stained-glass windows, prepared with the help of metal nanoparticles. The paper will deal with zeolites, nanoparticles and carbon nanotubes. The latter will be developed more extensively, because we have founded the Nanocyl company, selling carbon nanotubes and it has become the best European company. One carbon nanotube is 100,000 times thinner than a human hair, it is very light – twice as light as aluminium –, its mechanical resistance is much higher than that of steel and it conducts electricity better than metal conductors. The use of carbon nanotubes is very important in nanotechnology. For example, with the help of coiled carbon nanotubes, the weight of a single nanoparticle can be measured, it is equal to one femtogram (10-15 gram). Carbon nanotubes are used in car spray painting to cancel the build-up of static electricity. With the help of carbon nanotubes, it is possible to decrease the velocity of flame propagation, when they are included in composite materials. Carbon nanotubes are also very good as sensors for toxic gases. Their uses will take up the most part of this paper. The future of nanotechnology will be illustrated by nanomachines, by the lift between the Earth and the Moon, and by graphene (one single sheet of graphite). The use of carbon nanotubes will be evoked in waste water cleaning, in the production of drinking water from seawater
A nanotechnológia múltja, jelene és jövője
Már az ókori, mezopotámiai, egyiptomi, illetve a középkori művészek alkotásai, a különböző színű ablaküvegek is csodálatra késztetnek, melyeket fémnanorészecskék segítségével állítottak elő. A cikk röviden ismerteti a zeolitokat, a nanorészecskéket és a szénnanocsöveket. Ez utóbbiakat részletesen kifejtjük, mivel megalapítottunk egy Nanocyl nevű céget, mely szénnanocsöveket árul, és a legjobb európai cég lett. Egy szénnanocső 100 000-szer vékonyabb, mint egy hajszál, nagyon könnyű – kétszer könnyebb, mint az alumínium –, nagy az ellenálló képessége – sokkal nagyobb, mint az acélé –, és vezeti az áramot, sokkal jobban, mint a fémes vezetők. A szénnanocsövek alkalmazása nagyon fontos a nanotechnológiában. Például csavaros nanocsövek segítségével sikerült megmérni egyetlen nanorészecske súlyát, ami egy femtogramm (10–15 gramm). Szénnanocsöveket használnak az autófestékben, mellyel megszüntetik a statikus elektromosságot. Szénnanocsövek segítségével le lehet csökkenteni a tűz terjedésének sebességét, ha kompozit anyagokba bevisszük. Veszélyes gázok érzékelésére szenzornak is nagyon jók a szénnanocsövek. Jelen cikkben az alkalmazási területét mutatjuk be. A nanotechnológia jövőjét a nanogépek jellemzik; szó lesz a Föld és a Hold közötti liftről, a grafénről (egyetlen atomsíkból álló grafitlemez) és a valószínűleg a szénnanocsövek alkalmazására alapuló eljárásról, mely segít tengervízből ivóvizet gyártani és vizet tisztítani
Mixed-metal pillared layer clays and their pillaring precursors
Mixed-metal pillared layer clays (Fe,Al-PILCs and Cr,Al-PILCs)
of various compositions and the pillaring precursors have been
prepared and characterised with a combination of chemical and
instrumental methods. Chemical analysis data, IR, (57)Mossbauer
and Al-27 NMR spectroscopic measurements on the precipitated
pillaring precursors and comparison of redox behaviour
[temperature-programmed reduction (TPR) results and Fe-57
Mossbauer measurements on the heat-treated and the reduced
samples] of the ion-exchanged and Al-pillared and mixed-metal
pillared clays revealed that isomorphous substitution of Al for
Fe or Cr did not occur in either the tetrahedral or the
octahedral positions. Heat treatment, however, resulted in
mixed-metal pillared clays which were active in both acid-
catalysed and redox transformations
On the feasibility of iron or chromium substitution for aluminium in the Al13-Keggin ion
Al-27 NMR measurements in the liquid and the solid state supplemented with chemical analysis of the mixed salts; unambiguously reveal that neither tetrahedral nor octahedral aluminium can be substituted by either iron or chromium in Al-13-Keggin ion salts prepared by conventional methods
The Mongol Invasion of Hungary in Its Eurasian Context
This report gives an account of the historiography of the Mongol invasion of Hungary in 1241–1242, and the ongoing research of the project “The Mongol Invasion of Hungary in its Eurasian Context.” The research has been carried out by an interdisciplinary team comprising representatives of diverse academic institutions and fields. The primary objective of the project was to reassess existing scholarship by comparing it with the findings of the project team members, ultimately generating new scholarly insights. The team members concentrated on various aspects, including archaeology, military history, and the short- and long-term impacts of the Mongol military invasions in the mid-thirteenth century
Confirmation of the existence of the X17 particle
In a 2016 paper, an anomaly in the internal pair creation on theM1transition depopulating the 18.15 MeV isoscalar 1+ state on 8Be was observed. This could be explained by the creation and subsequent decay of a new boson, with mass mXc2=16.70 MeV. Further experiments of the same transition with an improved and independent setup were performed, which constrained the mass of the X17 boson (mXc2) and its branching ratio relative to the γ-decay of the 8Be excited state (BX), to mXc2=17.01(16) MeV and BX=6(1)×10−6, respectively. Using the latter setup, the e+e− pairs depopulating the 21 MeV Jπ=0−→0+ transition in 4He were investigated and a resonance in the angular correlation of the pairs was observed, which could be explained by the same X17 particle, with mass mXc2=16.98±0.16(stat)±0.20(syst) MeV
Expression of VEGF in neonatal urinary obstruction: does expression of VEGF predict hydronephrosis?
BACKGROUND In animal studies, the inhibition of VEGF activity results in high mortality and impaired renal and glomerular development. Mechanical stimuli, like mechanical stretch in respiratory and circulatory systems, results in an elevated expression of VEGF. In animal models, the experimental urinary obstruction is associated with stretching of tubular cells and activations of the renin-angiotensin system. This results in the upregulation of vascular endothelial growth factor (VEGF) and TNF-alfa. MATERIAL AND METHODS Tissue samples from urinary tract obstruction were collected and immunohistochemistry was performed in 14 patients (average age: 7.1+/-4.1 years). The control histology group consisted of ureteropelvic junction tissue from 10 fetuses after midtrimester artificial abortion. The fetuses did not have any failure at ultrasound screening and pathological examination. The mean gestational age was 20.6 weeks of gestation (+/-2.2SD). Expression of VEGF was detected with immunohistochemistry method. RESULTS Expression of VEGF was found in varying intensity in the submucosa and subserosa layers, but only in the test tissue (placental tissue). The tissue of the patients with urinary obstruction and the tissue of the fetal ureteropelvic junction without urinary obstruction were negative for expression of VEGF. The repeated examination showed negative cells and no color staining. CONCLUSIONS The pressure due to congenital urogenital obstruction resulting in mechanical stress in cells did not increase the expression of VEGF in young children in our study. To find a correlation between urogenital tract obstruction and increased expression of VEGF, we need to perform more examinations because the connection may be of therapeutic significance
Peripheral blood derived gene panels predict response to infliximab in rheumatoid arthritis and Crohn’s disease
Background: Biological therapies have been introduced for the treatment of chronic inflammatory diseases including rheumatoid arthritis (RA) and Crohn's disease (CD). The efficacy of biologics differs from patient to patient. Moreover these therapies are rather expensive, therefore treatment of primary non-responders should be avoided.
Method: We addressed this issue by combining gene expression profiling and biostatistical approaches. We performed peripheral blood global gene expression profiling in order to filter the genome for target genes in cohorts of 20 CD and 19 RA patients. Then RT-quantitative PCR validation was performed, followed by multivariate analyses of genes in independent cohorts of 20 CD and 15 RA patients, in order to identify sets ofinterrelated genes that can separate responders from non-responders to the humanized chimeric anti-TNFalpha antibody infliximab at baseline.
Results: Gene panels separating responders from non-responders were identified using leave-one-out cross-validation test, and a pool of genes that should be tested on larger cohorts was created in both conditions.
Conclusions: Our data show that peripheral blood gene expression profiles are suitable for determining gene panels with high discriminatory power to differentiate responders from non-responders in infliximab therapy at baseline in CD and RA, which could be cross-validated successfully. Biostatistical analysis of peripheral blood gene expression data leads to the identification of gene panels that can help predict responsiveness of therapy and support the clinical decision-making process
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