High-Resolution Contact Printing with Chemically Patterned Flat Stamps Fabricated by Nanoimprint Lithography

Chemically patterned flat stamps provide an effective solution to avoid mechanical stamp-stability problems currently encountered in microcontact printing. A new method is developed to fabricate chemical patterns on a flat PDMS stamp using nanoimprint lithography. Sub-100 nm gold patterns are successfully replicated by these chemically patterned flat PDMS stamps. \ud \u

Central role of nitric oxide in the pathogenesis of rheumatoid arthritis and sysemic lupus erythematosus

Nitric oxide (NO) has been shown to regulate T cell functions under physiological conditions, but overproduction of NO may contribute to T lymphocyte dysfunction. NO-dependent tissue injury has been implicated in a variety of rheumatic diseases, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Several studies reported increased endogenous NO synthesis in both SLE and RA, and recent evidence suggests that NO contributes to T cell dysfunction in both autoimmune diseases. The depletion of intracellular glutathione may be a key factor predisposing patients with SLE to mitochondrial dysfunction, characterized by mitochondrial hyperpolarization, ATP depletion and predisposition to death by necrosis. Thus, changes in glutathione metabolism may influence the effect of increased NO production in the pathogenesis of autoimmunity

Szén nanocső jellegű nanoszerkezetek előállítása, módosítása és jellemzése fizikai, kémiai és szimulációs módszerekre alapozva = Production, modification and characterization by physical, chemical and computer simulation of carbon nanotube type nanostructures

Kimutattuk, hogy a nem-hatszöges (n-H) gyűrűket is tartalmazó szén nanoszerkezetek (Y-elágazás, hengerspirálok, stb.) növekedését az n-H gyűrűk beépülésének mikéntje határozza meg, új modellt javasoltunk hengerspirálok szerkezetére. Elsőként készítettünk Si3N4/szén nanocső kompozitokat és megmutattuk, hogy megfelelő szinterelési paraméterek alkalmazásával megőrizhetők az elektromosan vezetővé tett mátrix jó tulajdonságai. Új nanocső növesztési módszereket dolgoztunk ki. Elsőként bizonyítottuk, hogy az ionos besugárzás nyomán a szén nanocsöveken, valóban a szimulációknak megfelelő topográfiai alakzatok jelennek meg. Elméleti modellt adtunk a hibák környezetében azt STM felvételeken megfigyelhető szuperstruktúrák eredetére. Megmutattuk, hogy a funkcionalizálás módjától függően a funkciós csoportok szigetszerűen, vagy folytonoshelyezkednek el. A funkciós csoportok megváltoztatják a nanocsövek válaszjelét a környezetben jelenlévő gázokra/gőzökre. Sikeresen fejlesztettünk elméleti módszereket a gyengén kölcsönható nagy atomszámú rendszerek leírására és elsőkként vizsgáltuk sok szén nanocsöből felépülő kötegekben a csövek egymással való kölcsönhatását. Első elvekre illetve sűrűségfunkcionál módszerre alapozva vizsgáltuk a duplafalú szén nanocsövek, illetve a nanocsőben elhelyezkedő szénláncok tulajdonságait. A sajátfejlesztésű hullámcsomagdinamikai módszerünkkel elsőkként vizsgáltuk az elektronhullámok terjedését szén nanocső Y elágazásokban. | We showed that the growth of carbon nanostructures containing non-hexagonal (n-H) rings (Y-branches, coils etc.) is determined by the incorporation of the n-H rings, we proposed a new model for the structure of regularly coiled carbon nanotubes. We prepared the first Si3N4/carbon nanotube composites and we showed the under proper sintering conditions the composite can be made conductive while keeping the remarkable properties of the matrix. We developed new growth methods for carbon nanotubes. We showed for the first time that ion irradiation of carbon nanotubes indeed creates the features predicted by simulations. We proposed a theoretical description of the superstructures observed in STM in the vicinity of the defects. Depending on the way in which the functionalization is done, the functional groups appear on the nanotubes in an island-like or a continuous fashion. Their presence influences the response of the carbon nanotubes to the gases/vapors present in the atmosphere. We developed successfully theoretical tools for the description of weakly interacting large system and investigated for the first time the interaction of tubes in carbon nanotube bundles containing many tubes. Based on first principle and density functional calculations we investigated the double wall carbon nanotubes and linear carbon chains located inside a SWCNT. Using our own wave packet dynamical software we investigated the propagation of electronic waves in carbon nanotube Y junctions

Postoperative differences between colonization and infection after pediatric cardiac surgery-a propensity matched analysis

BACKGROUND: The objective of this study was to identify the postoperative risk factors associated with the conversion of colonization to postoperative infection in pediatric patients undergoing cardiac surgery. METHODS: Following approval from the Institutional Review Board, patient demographics, co-morbidities, surgery details, transfusion requirements, inotropic infusions, laboratory parameters and positive microbial results were recorded during the hospital stay, and the patients were divided into two groups: patients with clinical signs of infection and patients with only positive cultures but without infection during the postoperative period. Using propensity scores, 141 patients with infection were matched to 141 patients with positive microbial cultures but without signs of infection. Our database consisted of 1665 consecutive pediatric patients who underwent cardiac surgery between January 2004 and December 2008 at a single center. The association between the patient group with infection and the group with colonization was analyzed after propensity score matching of the perioperative variables. RESULTS: 179 patients (9.3%) had infection, and 253 patients (15.2%) had colonization. The occurrence of Gram-positive species was significantly greater in the colonization group (p=0.004). The C-reactive protein levels on the first and second postoperative days were significantly greater in the infection group (p=0.02 and p=0.05, respectively). The sum of all the positive cultures obtained during the postoperative period was greater in the infection group compared to the colonization group (p=0.02). The length of the intensive care unit stay (p<0.001) was significantly longer in the infection group compared to the control group. CONCLUSIONS: Based on our results, we uncovered independent relationships between the conversion of colonization to infection regarding positive S. aureus and bloodstream results, as well as significant differences between the two groups regarding postoperative C-reactive protein levels and white blood cell counts

Heavyweight Dendritic Inks for Positive Microcontact Printing

Poly(propylene imine) dendrimers with dialkyl sulfide end groups were prepared and developed as inks for positive microcontact printing ((+)uCP) on gold. Long (C10H21-S-C10H20-), medium (C3H7-S-C4H8-), and short (CH3-S-CH2-) dialkyl sulfide end groups were attached to second- and third-generation PPI dendrimers to create a family of dendritic sulfides. The dendritic inks flatten upon adsorption and form monolayers on gold. (+)uCP was performed on gold using commercially available poly(dimethylsiloxane) as stamp material and n-octadecanethiol as etch resist. The gold beneath the dendrimers was selectively etched away with an acidic Fe(NO3)3/thiourea solution to give the positive copy of the original master pattern. The multivalent sulfide attachment and the relatively high molecular mass of these dendrimers ensured minimal lateral ink spreading and thus optimal feature reproducibility. Contact times were varied to analyze the spreading rates of the dendritic inks. The spreading rates of the dendritic inks were found to be much lower than that of pentaerythritol tetrakis(3-mercaptopropionate). (+)uCP with the new inks was extended to submicrometer features. Optical microscopy, scanning electron microscopy, and atomic force microscopy were used to characterize the etched samples. Lines with a width of 100 nm were faithfully replicated with the third-generation dendrimers bearing medium (C3-S-C4-) end groups

Bifunctional, Chemically Patterned Flat Stamps for Microcontact Printing of Polar Inks

Different methods to create chemically patterned, flat PDMS stamps with two different chemical functionalities were compared. The best method for making such stamps, functionalized with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (PFDTS) and 3-(aminopropyl)triethoxysilane (APTS), appeared to be full functionalization of a freshly oxidized flat PDMS stamp with either adsorbate, followed by renewed oxidation through a mask and attachment of the other adsorbate. These stamps were used to transfer polar inks (a thioether-functionalized dendrimer and a fluorescent dye) by microcontact printing. The PFDTS monolayer was used as a barrier against ink transfer, while the APTS SAM areas functioned as an ink reservoir for polar inks. The printing results confirmed the excellent transfer of hydrophilic inks with these stamps to gold and glass substrates, even from aqueous solutions. Attachment of a fluorescent dye on the amino-functionalized regions shows the possibility of the further modification of the chemically patterned stamps for tailoring of the stamps' properties

Enzyme-hydrolyzed fruit of Jurinea mollis: a Rich source of (-)-(8R,8’R)-Arctigenin

In Jurinea mollis fruit, the dibenzylbutyrolactone-type lignan glycoside arctiin and its aglycone arctigenin were determined for the first time using a combination of optimized enzymatic treatment and complementary spectrometric (HPLC-MS, GC-MS) and spectroscopic (CD and NMR) methods. Analysis of separated fruit parts, i.e., the fruit wall and embryo, demonstrated the specific accumulation of arctiin, since it was exclusively found in the embryo. Arctiin in the embryo samples (71.5 mg/g) was found to be quantitatively converted into arctigenin (50.7 mg/g) by endogenous enzymatic hydrolysis, resulting in one of the highest arctigenin-containing plant tissues reported to date and allowing the selective isolation of arctigenin by our recently reported three-step isolation method. The absolute configuration of the isolated arctigenin was determined to be (-)-(8R,8'R). Conformational analysis of arctigenin was also performed, resulting in three major low energy conformations

Mitochondrial involvement and erythronic acid as a novel biomarker in transaldolase deficiency

Item does not contain fulltextBACKGROUND: Sedoheptulose, arabitol, ribitol, and erythritol have been identified as key diagnostic metabolites in TALDO deficiency. METHOD: Urine from 6 TALDO-deficient patients and TALDO-deficient knock-out mice were analyzed using (1)H-NMR spectroscopy and GC-mass spectrometry. RESULTS: Our data confirm the known metabolic characteristics in TALDO-deficient patients. The beta-furanose form was the major sedoheptulose anomer in TALDO-deficient patients. Erythronic acid was identified as a major abnormal metabolite in all patients and in knock-out TALDO mice implicating an as yet unknown biochemical pathway in this disease. A putative sequence of enzymatic reactions leading to the formation of erythronic acid is presented. The urinary concentration of the citric acid cycle intermediates 2-oxoglutaric acid and fumaric acid was increased in the majority of TALDO-deficient patients but not in the knock-out mice. CONCLUSION: Erythronic acid is a novel and major hallmark in TALDO deficiency. The pathway leading to its production may play a role in healthy humans as well. In TALDO-deficient patients, there is an increased flux through this pathway. The finding of increased citric acid cycle intermediates hints toward a disturbed mitochondrial metabolism in TALDO deficiency.1 november 201