Search Results

You are looking at 11 - 18 of 18 items for

  • Author or Editor: T. Papp x
  • Refine by Access: All Content x
Clear All Modify Search
Journal of Thermal Analysis and Calorimetry
Authors:
S. Papp
,
L. Kőrösi
,
B. Gool
,
T. Dederichs
,
P. Mela
,
M. Möller
, and
I. Dékány

Abstract  

Gold nanoparticles (Au NPs) were prepared by the reduction of HAuCl4 acid incorporated into the polar core of poly(styrene)-block-poly(2-vinylpyridine) (PS-b-P2VP) copolymer micelles dissolved in toluene. The formation of Au NPs was controlled using three reducing agents with different strengths: hydrazine (HA), triethylsilane (TES), and potassium triethylborohydride (PTB). The formation of Au NPs was followed by transmission electron microscopy, UV–Vis spectroscopy, isothermal titration calorimetry (ITC), and dynamic light scattering (DLS). It was found that the strength of the reducing agent determined both the size and the rate of formation of the Au NPs. The average diameters of the Au NPs prepared by reduction with HA, TES, and PTB were 1.7, 2.6, and 8 nm, respectively. The reduction of Au(III) was rapid with HA and PTB. TES proved to be a mild reducing agent for the synthesis of Au NPs. DLS measurements demonstrated swelling of the PS-b-P2VP micelles due to the incorporation of HAuCl4 and the reducing agents. The original micellar structure rearranged during the reduction with PTB. ITC measurements revealed that some chemical reactions besides Au NPs formation also occurred in the course of the reduction process. The enthalpy of formation of Au NPs in PS-b-P2VP micelles reduced by HA was determined.

Restricted access

Earlier neurochemical studies suggested that human brain carboxypeptidase B may play a significant role in the degradation of amyloid-β1-42 in the brain. Using an immunohistochemical technique we report here on the neuronal expression and distribution of this enzyme in the segments (CA1a, CA1b and CA1c) of the CA1 subfield and in area CA4 of the hippocampus in normal and Alzheimer's disease brain samples. Its distribution was compared with the appearance of neurofibrillary tangles in the same brain sample. For immunohistochemical localization of carboxypeptidase B, a specific C14-module antibody was applied, together with the Gallyas silver impregnation technique for the demonstration of neurofibrillary tangles. The results revealed that, in the control samples, most of the immunoreactivity appeared in segment CA1a in the pyramidal cells, less in segment CA1b and least in segment CA1c. In the Alzheimer's disease samples, there was no particular immunostaining in the neurons, but, a large number of silver-impregnated degenerated neurons appeared. The results support the suggestion that carboxypeptidase B may play a significant role in elimination of the intracellular accumulation and toxicity of amyloid-β in the human brain and thereby protect the neurons from degeneration.

Restricted access
Acta Biologica Hungarica
Authors:
L. G. Puskás
,
L. Tiszlavicz
,
Zs. Rázga
,
L. L. Torday
,
T. Krenács
, and
J. Gy. Papp

Recent and historical evidence is consistent with the view that atherosclerosis is an infectious disease or microbial toxicosis impacted by genetics and behavior. Because small bacterial-like particles, also known as nanobacteria have been detected in kidney stones, kidney and liver cyst fluids, and can form a calcium apatite coat we posited that this agent is present in calcified human atherosclerotic plaques. Carotid and aortic atherosclerotic plaques and blood samples collected at autopsy were examined for nanobacteria-like structures by light microscopy (hematoxylin-eosin and a calcium-specific von Kossa staining), immuno-gold labeling for transmission electron microscopy (TEM) for specific nanobacterial antigens, and propagation from homogenized, filtered specimens in culture medium. Nanobacterial antigens were identified in situ by immuno-TEM in 9 of 14 plaque specimens, but none of the normal carotid or aortic tissue (5 specimens). Nanobacteria-like particles were propagated from 26 of 42 sclerotic aorta and carotid samples and were confirmed by dot immunoblot, light microscopy and TEM. [3H]L-aspartic acid was incorporated into high molecular weight compounds of demineralized particles. PCR amplification of 16S rDNA sequences from the particles was unsuccessful by traditional protocols. Identification of nanobacteria-like particles at the lesion supports, but does not by itself prove the hypothesis that these agents contribute to the pathogenesis of atherosclerosis, especially vascular calcifications.

Restricted access

Extracellular β-glucosidase activity of 94 strains, representing 24 species of the genera Gilbertella, Mucor, Rhizomucor , and Rhizopus was evaluated in submerged culture and under solid state fermentation on wheat bran. Gilbertella persicaria G1 isolate showed the highest activity (70.9 U ml −1 ) followed by other Gilbertella (58.6–59.0 U ml −1 ) and Rhizomucor miehei isolates (29.2–42.0 U ml −1 ). Optimum temperature for enzyme production was 25 °C for Gilbertella and Mucor , and 30 °C for Rhizomucor and Rhizopus strains. Enzymes of R. miehei strains proved to be thermotolerant preserving up to 92.8% residual activity after heating to 75 °C in the presence of cellobiose substrate. Enzymes of Mucor racemosus f. chibinensis, R. miehei and Rhizopus microsporus var. oligosporus strains were activated at acidic condition (pH 4). Glucose was a strong inhibitor for each fungal β-glucosidase tested but some of them showed ethanol tolerance up to 20% (v/v). Ethanol also activated the enzyme in these strains suggesting glycosyl transferase activity.

Restricted access

A Vibrant Soundbridge aktív középfül-implantátum történeti áttekintése és sebészi alkalmazásának lehetőségei

Historical overview and surgical applications of the Vibrant Soundbridge active middle ear implant

Orvosi Hetilap
Authors:
Tamás Tóth
,
Imre Gerlinger
,
T. Barbara Bölcsföldi
,
György Kellényi
,
Adrienne Németh
,
István Papp
, and
István Szanyi

Összefoglaló. A Vibrant Soundbridge aktív középfül-implantátum vezetéses, sensorineuralis és kevert típusú halláscsökkenés esetén is megoldást jelenthet a beteg hallásrehabilitációja során. Sensorineuralis halláscsökkenés esetén akkor indikálható, ha a légvezetéses hallásküszöb nem haladja meg a 80–85 dBHL-t a 3–4 kHz frekvenciákon, vezetéses, illetve kevert típusú halláscsökkenés esetén pedig akkor, ha a csontvezetéses hallásküszöb nem haladja meg a 45–65 dBHL-t a 0,5–4 kHz közti frekvenciatartományban. Az implantátum beültetését eleinte tisztán sensorineuralis halláscsökkenés esetén végezték, és csupán egyféleképpen történhetett: a rezgéskeltő rendszer oldalán lévő rögzítőcsipeszt rá kellett applikálni az incus hosszú nyújtványára. Azokra az esetekre, amikor a rezgéskeltő rögzítése nem kivitelezhető, különböző rögzítőelemeket (coupler) fejlesztettek ki. Az incusra való rögzítés hosszúnyújtvány-couplerrel, illetve rövidnyújtvány-couplerrel lehetséges. Vezetéses és kevert típusú halláscsökkenés esetén a kerek ablak membránjához is illeszthető a rendszer, előrehaladott otosclerosis esetén pedig a Soundbridge-implantáció stapedotomiával kiegészített változata („power stapes”) hozhat kielégítő halláseredményt. Ezek a technikák meglehetősen megnövelték a sebész szabadságát, így széles körben alkalmazott, megbízható megoldássá váltak. A Pécsi Tudományegyetem Fül-Orr-Gégészeti és Fej-Nyaksebészeti Klinikáján az elmúlt évtizedben számos incusvibroplastica történt, de kerekablak-vibroplasticára is több alkalommal sor került. A jelen összefoglaló tanulmányban a Vibrant Soundbridge implantátum technikai fejlődésének történeti áttekintésén felül az alkalmazható műtéti megoldásokat mutatjuk be. Orv Hetil. 2021; 162(40): 1619–1626.

Summary. The Vibrant Soundbridge active middle ear implant can provide a reliable solution for hearing rehabilitation of patients with conductive, sensorineural or mixed hearing loss. For sensorineural hearing loss, the air conduction threshold of the patient should not be more increased than 80–85 dBHL at the range of 3–4 kHz, and for conductive and mixed hearing loss, the bone conduction threshold should not be more increased than 45–65 dBHL between 0.5 and 4 kHz. The standard surgical procedure was originally designed for purely sensorineural hearing loss, and the fixation clip of the vibrating transducer needed to be crimped onto the long process of the incus. In many cases, it is impossible to crimp the vibrator onto the incus. In order to solve such circumstances, fixation clips (couplers) have been developed. There are two options to crimp the device on the incus: applying a long process coupler or a short process coupler. For conductive or mixed hearing loss, a round window soft coupler has been introduced. In advanced otosclerotic cases, a special combined technique of Soundbridge implantation with simultaneous stapedotomy can result in sufficient hearing rehabilitation. These techniques significantly broadened the scale of possibilities for the implantation, therefore, it became a widely utilized, reliable procedure. At the Department of Otorhino-laryngology, Clinical Center, University of Pécs, in addition to a noteworthy amount of incus vibroplasty, several cases of round window vibroplasty have also been performed. The aim of the present study is to summarize the history of development of the Vibrant Soundbridge and to present an overview of the applicable surgical techniques. Orv Hetil. 2021; 162(40): 1619–1626.

Open access
Interventional Medicine and Applied Science
Authors:
K. Szakszon
,
Z. L. Veres
,
M. Boros
,
S. Sz. Kiss
,
B. Nagy
,
E. Bálega
,
á. Papp
,
E. Németh
,
I. Pataki
, and
T. Szabó

Abstract

We report a case of an infant with spontaneous chylothorax due to the congenital malformation of a small lymph vessel of the chest wall. Conservative therapy with omitting long-chain fatty acids from the diet, fat-free nutrition, total parenteral nutrition and intravenous somatostatin did not result in the decrease of pleural effusion. Thoracic surgical intervention performing thoracic duct ligation and using fibrin sealants was applied after 10 days of unsuccessful conservative therapy, and resulted in the complete recovery of the patient. Our experience support the already existing observations, that in cases where the daily loss of chyle exceeds 100 ml per age years and/or lasts longer than 2 weeks, early surgical intervention is recommended.

Restricted access
Acta Botanica Hungarica
Authors:
P. Török
,
T. Miglécz
,
O. Valkó
,
K. Tóth
,
A. Kelemen
,
Á.-J. Albert
,
G. Matus
,
A. Molnár V
,
E. Ruprecht
,
L. Papp
,
B. Deák
,
O. Horváth
,
A. Takács
,
B. Hüse
, and
B. Tóthmérész

In the present paper we report original thousand-seed weight data for the flora of the Pannonian Basin. Our goal was to demonstrate the usefulness of seed weight databases by analysing seed weight data in relation to social behaviour types and life forms. We specifically asked the following questions: (i) how the seed weights are related to social behaviour type categories; (ii) how the life form of the species influences seed weight differences between respective social behaviour types? Own weight measurements are provided for 1,405 taxa; and for 187 taxa we published seed weight data for the first time: these were mostly endemics, orchids and/or species with Pontic, Caspian or continental distribution. Several taxonomic or functional groups are underrepresented in our database, like aquatic plants, rare arable weeds and sub-Mediterranean species. Problematic taxa, some difficult-to-harvest species or species with low seed production and cultivated adventives are also underrepresented. We found that the plant strategies expressed by social behaviour types were significantly different in terms of seed weights. The lowest seed weight scores were found for natural pioneers, whereas the highest ones were found for adventives and introduced cultivated plants. Short-lived herbaceous species had significantly higher seed weight scores than herbaceous perennials. No significant differences were found between specialists and generalists within the stress tolerant group. We found that short-lived graminoids possess heavier seeds than perennial graminoids, perennial and annual forbs. Naturalness scores were negatively correlated with seed weights. Our findings showed that seed collections and databases are not only for storing plant material and seed weight data, but can be effectively used for understanding ecological trends and testing plant trait-based hypotheses. Even the identified gaps underline the necessity of further seed collection and measurements.

Restricted access
Acta Botanica Hungarica
Authors:
P. Török
,
E. Tóth
,
K. Tóth
,
O. Valkó
,
B. Deák
,
B. Kelbert
,
P. Bálint
,
Sz. Radócz
,
A. Kelemen
,
J. Sonkoly
,
T. Miglécz
,
G. Matus
,
A. Takács
,
V. A. Molnár
,
K. Süveges
,
L. Papp
,
L. Papp Jr.
,
Z. Tóth
,
B. Baktay
,
G. Málnási Csizmadia
,
I. Oláh
,
E. Peti
,
J. Schellenberger
,
O. Szalkovszki
,
R. Kiss
, and
B. TÓthmérész

For understanding local and regional seed dispersal and plant establishment processes and for considering the ecotypes and other forms of specific variability, hard data of locally or regionally measured traits are necessary. We provided newly measured seed weight data of 193 taxa, out of which 24 taxa had not been represented in the SID, LEDA or BiolFlor databases. Our new measurements and formerly published data of locally collected seed weight records together covers over 70% of the Pannonian flora. However, there is still a considerable lack in seed weight data of taxonomically problematic genera, even though they are represented in the Pannonian flora with a relatively high number of species and/or subspecies (e.g. Sorbus, Rosa, Rubus, Crataegus and Hieracium). Our regional database contains very sporadic data on aquatic plants (including also numerous invasive species reported from Hungary and neighbouring countries) and some rare weeds distributed in the southwestern part of the country. These facts indicate the necessity of further seed collection and measurements.

Restricted access