Search Results

You are looking at 91 - 100 of 10,163 items for :

  • "concentration" x
  • All content x
Clear All

). Amniotic fluid glucose concentration . Am. J. Obstet. Gynecol. 120 , 40 – 48 . Fresno , L. , Rodriguez-Gil , J. E. , Rigau , T. , Pastor , J. and Rivera del Alamo , M. M

Restricted access
Acta Biologica Hungarica
Authors: Barbara Barna, A. Szász, T. Asztalos, Z. Szupera, L. Vécsei, Helmi Houtzager, and Magdolna Szente

In the present electrophysiological study the effect of aminooxyacetic acid (AOAA) on the cortical epileptogenicity, and on the basic electro-cortical activity was investigated in anesthetized rats.AOAA did not induce spontaneous epileptiform discharges but modified the somato-sensory evoked responses and the cortical epileptogenicity (induced by 4-aminopyridine) in the same manner depending on its concentration. AOAA at low concentrations increased the amplitude of evoked responses and the ipsilateral manifestation of epileptiform activity, however, at high concentrations significantly suppressed both the evoked responses and the induction and expression of seizures discharges. The anticonvulsive effect of AOAA was time-dependent (reached its maximum after 2h AOAA pre-treatment) and reversible. AOAA at low concentrations probably increases the efficacy of the NMDA excitatory system and decreases GABA-synthesis, resulting neuronal hyperexcitation. However, AOAA at high concentrations can lead to an effective cortical inhibition through intra- and extracellular accumulation of GABA. The gradual GABA accumulation - up to a certain level - at the synapses could also explain the time-dependency of the anticonvulsive effect of AOAA.

Restricted access
Acta Veterinaria Hungarica
Authors: Zoltán Szelényi, Orsolya Gabriella Balogh, Fernando Lopez-Gatius, Irina Garcia-Ispierto, Eszter Krikó, and György Gábor

-Novales , R. and López-Gatius , F. ( 2016 ): Plasma concentrations of pregnancy-associated glycoproteins I and II and progesterone on day 28 post-AI as markers of twin pregnancy in dairy cattle . Liv. Sci. 192 , 44 – 47

Restricted access

Carrot is an important source of sugars. The objective of this study was to investigate the effects of water supply (precipitation + irrigation) on the concentration and ratio of fructose, glucose, and sucrose in carrot. Irrigation did not decrease the dry matter content and the summed concentration of the three measured sugars. Glucose accumulation was not influenced either by irrigation or by year. Low amount of precipitation during the early growing period was detrimental for fructose accumulation. Irrigation enhanced sucrose concentration, presumably by ensuring better photosynthetic activity. However, dry and hot weather during the irrigation cut-off period in 2011 also resulted in increased sucrose accumulation, presumably as a stress effect. It was found that irrigation did not influence the ratio of the three investigated saccharides at all, and even the growing year had just a slight effect on that.

Restricted access

Abstract  

There are two types of lakes in the vicinity of the nuclear fuel cycle facilities in Rokkasho-mura. One is a brackish lake, Obuchinuma Lake, and the other is a freshwater lake, Takahokonuma Lake. Tritium concentrations in Obuchinuma Lake had a good negative correlation with salinity at any sampling point and period. We consider that the water of Obuchinuma Lake has been only slightly influenced by precipitation depending on the ratio of seawater and river water of the Futamata River. Tritium concentrations in Takahokonuma Lake ranged from 0.6 to 1.5 Bq·1-1, and were higher than that in precipitation in Rokkasho-mura. Tritium concentration in rivers flowing into the lakes ranged from 0.7 to 2 Bq·l-1, and were higher than that in the precipitation. It is assumed that ground waters with higher levels of tritium inflow into the rivers.

Restricted access

Abstract  

To examine the radionuclide concentrations in the environment, seaweeds were collected once a year since 1976 at two different places. A marked change was observed in the number of radionuclides in seaweeds. The increase of radionuclides is attributed to contamination by radioactive fallout from Chinese nuclear explosion tests. The radionuclide concentrations were strongly dependent on the species of seaweeds. A gradual decrease of the137Cs/40K activity ratio was observed in spite of the input of additional137Cs fallout from Chinese nuclear tests. This implies that the amounts of137Cs introduced into seawater by these detonations were small in comparison with those already contained in seawater. The cesium content in seawater was estimated by using specific activities of137Cs in seaweeds and137Cs concentration in seawater. The results show good agreement with the reported values by direct analysis of seawater.

Restricted access

Abstract  

The role of fluorine, as a corrosion inhibitant was investigated by determining fluorine concentration profiles in corroded MAGNOX reactor fuel cladding material. A nuclear convolution method was employed, based on the19F(p, αγ)16O resonant reaction and prompt gamma detection. The investigation was carried out for scale thicknesses of 3.5 and 4.5 μm as determined using 4.5 MeV protons and a broad resonance in16O(p, p)16O back-scattering cross-section. The results indicate the presence of thin fluorine concentration layers near to the scale surface on both etched and pre-oxidized magnesium alloy samples. Furthermore, an additional lower concentration distribution was also observed throughout the scale of the pre-oxidized sample.

Restricted access

Abstract  

Indoor radon concentrations in the kidergartens of Osijek, Croatia, have been measured with -scintillation cells, LR-115 nuclear track detectors, as well as a Radhome semiconductor detector. Average values of 50.2, 43.7 and 47 Bq m–3 were obtained, respectively. Under the worst conditions, the annual radon effective dose equivalent was 10 mSv y–1. Using bare and filtered LR-115 detectors, the average equilibrium factor was assessed as 0.36 indoors. Measurements of the -dose rate in the kindergartens did not show any significant correlation with the radon concentration. Indoor radon concentrations in the kindergartens of Ljubljana, Slovenia, measured by scintillation cells had an arithmetic mean and standard deviation of 228 and 143 Bq m–3, respectively.

Restricted access

Abstract  

The hydrogen concentration for the reference material low-alloy steel was estimated using prompt gamma neutron activation analysis. The hydrogen concentration had a range of 0.91–1.14 mg/kg as measured by the prompt gamma activation method but the reference value was about 1.0 mg/kg as measured by the ICP/AES method. The relative error appeared to be 14% and the differences showed as the background by blank. The standard reference material (NIST SRM) was used for the analytical control.

Restricted access

Abstract  

The distribution coefficient of silver for a strongly acidic cation exchanger of the sulfonic acid type was measured as a function of time, pH, the concentration of silver and of the bulk electrolyte. At lower pH, the distribution coefficient increases with increasing pH, with a slope of +1. The distribution coefficient then decreases with increasing pH with a slope between −0.2 and −0.3. The tendency was the same for four brands of exchanger. The distribution coefficient decreases with decreasing concentration of silver. The phenomena cannot be attributed to silver hydrolysis or silver radiocolloid formation but should be ascribed to the substance released from the exchange resin itself.

Restricted access