Proton exchange membrane with plasmon-active surface for enhancement of fuel cell effectivity.

The action of fuel cells with proton-exchanged membranes (PEMs) requires the implementation of the hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR) on the opposite sides of the PEMs. Recently, based on several models of electrochemical reactions a significant decrease in the thermodynamic activation barrier of both reactions under plasmon assistance was reported. In this work, we propose the design of a PEM fuel cell with a plasmon-active catalytic surface providing plasmonic triggering and enhancement of fuel cell efficiency. In particular, we deposited bimetallic (Au@Pt) nanostructures on the PEM surface and integrated them into the fuel cell design. Plasmon excitation occurs on the Au nanostructures under light illumination at the corresponding NIR wavelength, while the Pt shell is responsible for the introduction of catalytic sites. Light illumination results in a significant enhancement of the electric current produced by the fuel cell. In particular, the electric current increased several times. Control experiments indicated that the observed enhancement takes place only when the light wavelength is in compliance with the plasmon absorption band and the contribution from thermal effects is negligible. The present approach for the introduction of plasmon assistance into the design of advanced fuel cells makes them suitable for increasing the fuel cell efficiency under sunlight.

UH3-based ferromagnets: new look at an old material.

UH3 is the first discovered material with ferromagnetism based purely on the 5f electronic states, known for more than half century. Although the U metal is Pauli paramagnet, the reduced 5f-5f overlap in compounds allows for moment formation and ordering, typically if the U-U spacing exceeds the Hill limit, i.e. about 340 pm. The stable form of UH3, known as ß-UH3, has rather high TC ≈ 170 K. Such high value is rather unusual, considering dU-U = 331 pm. Properties of metastable α-UH3 with dU-U = 360 pm could be never well established. Using the fact that α-UH3 is in fact bcc U with interstitials filled by H, we attempted to synthesize α-UH3 starting from the γ-U alloys, with the bcc structure retained to room temperature by doping combined with ultrafast cooling. While up to 15% Zr a contamination by ß-UH3 was obtained, 20% Zr yielded single phase α-UH3. The TC value remains high and very similar to ß-UH3. One can see an increase up to 187 K for 15% Zr, followed by a weak decrease. Magnetic moments remain close to 1 µB/U atom. An insight is provided by ab-initio calculations, revealing a a charge transfer towards H-1s states, depopulating the U-6d and 7s states, leaving almost pure 5f character around the Fermi level. The 5f magnetism exhibits a high coercivity (µ0Hc up to 5.5 T) and large spontaneous volume magnetostriction of 3.2*10-3. Even higher increase of TC, reaching up to 203 K, can be achieved in analogous Mo stabilized hydrides, which yield an amorphous structure. The compounds represent, together with known hydrides of U6Fe and U6Co, a new group of robust 5f ferromagnets with small dU-U but high TC. Although common hydrides are fine powders, some of the new hydrides described as (UH3)(1-x)T x (T = Zr or Mo) remain monolithic, which allows to study transport and thermodynamic properties.

Electronic properties of α-UH3 stabilized by Zr.

Pure hydride of the α-UH3 type without any ß-UH3 admixture was prepared by high-pressure hydrogenation of bcc U stabilized by Zr. Such material, characterized by a general formula (UH3)1-x Zr x , is stable in air at ambient and elevated temperatures. H release is observed between 400-450 °C similar to ß-UH3. Its stability allowed to measure magnetic properties, specific heat, and electrical resistivity in a wide temperature range. Despite rather different crystal structure and inter-U spacing, the electronic properties are almost identical to ß-UH3. Its ferromagnetic ground state with Curie temperature TC ≈ 180 K (weakly and non-monotonously dependent on Zr concentration) and U moments of 1.0 µB indicate why mixtures of α- and ß-UH3 exhibited only one transition. Magnetic ordering leads to a large spontaneous magnetostriction ωs = 3.2*10-3, which can be explained by the increase of the spin moment between the paramagnetic (Disordered Local Moment) and the ferromagnetic state. The role of orbital moments in magnetism is indicated by fully relativistic electronic structure calculations.

[The analysis of the incidence of meningitis in children]. / Analiza zachorowan na zapalenie opon mózgowo-rdzeniowych u dzieci do trzeciego roku zycia.

The aim of the study is to present the results of epidemiological investigation in 142 infants and young children who suffered from meningitidis in the years 1987-1995. The most frequent cause of the disease was bacterial infection. The bacterial factors have been identified in 49% of those cases. Neisseria meningitidis was found to be most common bacteria that was responsible for the disease.

[Congenital esophageal atresia with tracheo-esophageal lower fistula and infectious asthma complicated by severe status asthmaticus which required use of halogen ether inhalants--case report]. / Wrodzona atrezja przelyku z dolna przetoka przelykowo-tchawicza a astma infekcyjna z ciezkimi stanami astmatycznymi, wymagajacymi stosowania wziewnych eterów halogenowych--opis przypadku.

A five-year clinical study of a boy operated in the first day of his life due to esophageal atresia with tracheo-esophageal lower fistula has been presented, in whom severe endogenic asthma complicated by frequent status asthmaticus developed, which required application of inhalatory anaesthetics.

[Use of inhalation anesthetics in treatment of severe status asthmaticus and for anesthesia in children suffering from bronchial asthma. Preliminary report]. / Zastosowanie wziewnych srodków anestetycznych w leczeniu ciezkich stanów astmatycznych oraz w znieczuleniu u dzieci chorych na astme oskrzelowa. Doniesienie wstepne.

This paper presents preliminary estimation of clinical usefulness of isoflurane for treatment of severe cases of status asthmaticus in children and application of it as monoanesthesia in children with bronchial asthma, operated upon sudden indications. Action and metabolism of halogen ether group inhalatory anaesthetics in human organism was discussed, with special attention being paid to isoflurane and ketamine. In the cases studied (which is also confirmed by numerous clinical tests) potentialization of bronchodilatative effect of isoflurane by intravenous application of ketamine in status asthmaticus was observed. Where the results achieved was linked up with increased concentration of catecholamines and direct atonic effect on smooth muscular coat of bronchus.

[Lead poisoning in children from the industrial region of Silesia--markers of chronic intoxication]. / Intoksykacja olowiowa u dzieci w wielkoprzemyslowym rejonie slaska--markery przewleklego zatrucia.

In the paper the degree of lead micro-intoxication was assessed in school children from the region of emissions of the Mining-Ironworks Complex "Boleslaw" in Bukowno. The study included 323 children of either sex aged from 7 to 14 years. In these children the levels of selected lead intoxication markers were determined--concentration of zinc protoporphyrin (ZnPP) in the erythrocytes and concentration of delta-amino-laevulinic acid (ALA) in urine. The obtained results were compared with corresponding results in the control group which consisted of 163 children of the same age, living in a control area without exposure to heavy metals. In the studied group in all age subgroups, significantly higher ALA concentrations in urine were observed in comparison to the control group. At the same time, exceeding of upper acceptable range of ALA concentration in the organism was five times more frequent in this group. On the other hand, the concentration of ZnPP in the erythrocytes failed to show any significant differences between the compared groups in any of the analysed age subgroups. On the basis of the obtained results it was demonstrated that the school children living in the region of emissions of the MIC "Boleslaw" had biochemical features of long-term lead microintoxication. As it seems, the concentration of ALA in urine is of greater diagnostic value in comparison to the concentration of ZnPP in the erythrocytes in screening examinations in these children.

[Lead poisoning in children from the industrial region of Silesia--hematologic indices]. / Intoksykacja olowiowa u dzieci w wielkoprzemyslowym rejonie slaska--wskazniki hematologiczne.

In the paper, the basic parameters of blood morphologic pattern were assessed in school children exposed to toxic heavy metal emission. The studies included 323 children aged from 7 to 14 years, living in the region of emissions of the Mining-Ironworks Complex "Boleslaw" in Bukowno. In these children haemoglobin concentration, haematocrit and erythrocyte and leucocyte counts were determined using routine laboratory tests. The obtained results were compared with corresponding results in the control group which consisted of 163 children of either sex living in a control region without exposure to heavy metals. In the studied group in most age subgroups significant decreases of erythrocyte count haemoglobin concentration and increases of haematocrit value were observed in comparison to the control group. At the same time, in these children, ten times higher, in relation to the control group, incidence was found of haemoglobin concentrations below 120 g/l, characteristic of anaemia. As it seems, one of important factors causing the decrease of the value of the parameters of blood morphologic pattern in the studied children is chronic microintoxication with lead, manifesting itself as significantly increased concentration of delta-amino-laevulinic acid in urine which is a sensitive marker of this intoxication.

[Values of peak expiratory flow in children of school age with biochemical indices of lead intoxication]. / Wartosci szczytowego przeplywu wydechowego u dzieci w wieku szkolnym z biochemicznymi wyznacznikami intoksykacji olowiowej.

The study was carried out on 541 school children in region with heavy metals air pollution and on 530 children as a control group from free of pollution area. A special attention was layed upon lead intoxication influence on values of PEF. The decrease of PEF values in children in polluted region was documented and suggested close link with lead intoxication.

[Pneumocystis pneumonia in infants]. / Pneumocystozowe zapalenie pluc u niemowlat.

The acute and chronic forms are described of pneumocystis interstitial pneumonia in two infants which were observed during a hospital epidemic. The microscopic examination of bronchial secretion from the subglottic region made possible the use of guided treatment.

[Epidemic of Pneumocystis carinii infection in infants]. / Epidemiczne zakazenie Pneumocystis carinii u niemowlat.

Epidemic intra-ward infection caused by Pneumocystis carinii was described. 18 infants and small children were ill from among 21 treated in the infants ward. The diagnosis was given on the grounds of cytologic examination of bronchial excretion from subglottic region.

[Basic indicators of physical development of schoolchildren living in the area of an industrial plant processing non-ferrous metals]. / Podstawowe wskazniki rozwoju fizycznego dzieci szkolnych zamieszkalych w rejonie oddzialywania zakladu przemyslu metali niezelaznych.

The purpose of the study was an analysis of the basic indices of somatic development of school children in the Olkusz area with mines of zinc, lead and cadmium, and metallurgic plants processing the ores of these metals. The studied group comprised 747 children aged 5 to 14 years attending randomly selected schools in Olkusz, Bukowna and Boleslaw. The height and body mass were measured on medical scales with height scale. The obtained results were compared with those of similar measurements of children in other parts of the country with different degrees of environmental pollution with non-iron metals. In the Olkusz area the height of the children was slightly smaller than in other parts.

[Comparison of the degree of peak expiratory flow (PEF) in children measured with a "Vitalograph" meter and automatic spirometer SA-02]. / Porównanie wielkosci szczytowego przeplywu wydechowego (PEF) u dzieci mierzonego miernikiem firmy "Vitalograph" i spirometrem automatycznym SA-02.

PEF values in 475 healthy children (age 9-15 years, 138 females, 337 males) measured with a Vitalograph meter and an automatic spirometer SA-02 were compared. The results were comparable in all except in 9, 10, 11 year old boys, in whom the PEF values measured with a Vitalograph meter were statistically higher in comparison with the readings given by the automatic spirometer. The authors have demonstrated the high reliability of the Vitalograph meter in assessing PEF.

[Staphylococcal septicemia in a newborn infant with multiple organ involvement]. / Posocznica gronkowcowa u noworodka z wielonarzadowym umiejscowieniem zmian chorobowych.

The clinical course and therapeutic problems are presented in a case of staphylococcal septicaemia in a newborn. Generalized infection was associated with multiorgan location of pathological changes, among them, acute haematogenous osteitis and arthritis (of the temporomandibular joint, shoulder joint, hip, elbow joint, knee joint and wrist joint) and rarely occurring parotitis.

[Usefulness of forced expiratory flow rate measurements in diagnosis of selected lung diseases in children]. / Przydatnosc pomiaru szczytowego przeplywu wydechowego (PEF) w diagnostyce niektórych chorób pluc u dzieci.

The study group was composed of 2512 healthy children (age range 7-15 years) randomly selected from schools of the Upper Silesian Industrial District. In each child 5 PEF measurements were carried out using the Vitalograph meter. A statistical analysis of the results was carried out. The results seen in tables and centile charts can be used as normal values for children in given age groups and sex. PEF is useful in clinical diagnosis of different respiratory diseases.

[Hypochromic anemia associated with ascariasis and giardiasis in children]. / Niedokrwistosc niedobarwliwa towarzyszaca glistnicy i giardiazie u dzieci.

The purpose of the study was determination of the frequency of the association of hypochromic anaemia with infections by Ascaris lumbricoides and Giardia intestinalis. Among 5603 studied patients of either sex, aged 3 to 18 years ascaridiasis alone was diagnosed in 226 children (4%), and giardiasis alone in 106 cases (1.9%). The frequency of this anaemia in these groups ranged from 6% to 16%.