bluuebunny/crossref_metadata_2025 huggingface dataset:
New data on the crystal structures of natural zirconosilicates: structure refinements and ion-exchange behavior
Authors: Zubkova Natalia V. , Pushcharovsky Dmitry Yu.
Published: February 2008

A review of the mineralogical, structural and crystal-chemical studies carried out on a large group of natural zirconosilicates is reported. These zirconosilicates belong to a large number of distinct structural types, and those with mixed frameworks of isolated Zr-centred octahedra and silicate complexes are described according to the degree of condensation of SiO4 tetrahedra.The microporous heteropolyhedral nature of these phases is considered in connection with their ion exchange properties. The application of X-ray diffractometers equipped with CCD detectors, use of the Rietveld method, and electron microprobe and IR spectroscopic data provide new insights into the structural peculiarities of these minerals. The results stimulate the search for new Zr—Si-compounds with potential applications in the areas of catalysis, separation of molecules, ion exchange, etc.
Minerals with antiperovskite structure: a review
Authors: Krivovichev Sergey V.
Published: February 2008

Antiperovskites or inverse perovskites are inorganic compounds with a perovskite structure but with cations replaced by anions and vice versa. It is shown that there exists a number of minerals whose structures can be regarded as based upon antiperovskite units composed of face-and corner-sharing octahedra. The structures of sulphohalite, galeite, schairerite, kogarkoite, nacaphite, arctite, polyphite, hatrurite and related compounds are considered. The 3C, 2H, 5H, 7H, 9R and 15R antiperovskite polytypes are described. In some cases, antiperovskite modules are intercalated with intermediate ions and complexes.
Minerals and synthetic Pb(II) compounds with oxocentered tetrahedra: review and classification
Authors: Siidra Oleg I. , Krivovichev Sergey V. , Filatov Stanislav K.
Published: February 2008

The crystal structures of minerals and inorganic compounds with OPb4 oxocentered tetrahedra are reviewed. It is shown that the OPb4 tetrahedral units may link by sharing common Pb atoms to form structural units of various shape and dimensionality. These units determine basic topology of the structures and influence their stability and properties. The high strength of the OPb4 te trahedral units involves interplay between high basicity of additional O2– anions and stereochemical activity of the 6s
2 lone electron pairs on Pb2+ cations. The structural chemistry of polycations based upon OPb4 tetrahedra, in general, follows major trends previously observed for cation-centered tetrahedral units (silicates, phosphates, metal sulphides with MS4 tetrahedra, etc.). One may conclude that the basic structural correlations depend upon size and charge parameters of the ions only, irrespective of their positive or negative sign.
Phosphates with amphoteric oxo-complexes: from structural features to genetic conclusions
Authors: Yakubovich Olga V.
Published: February 2008

Structural peculiarities of phosphate minerals are discussed in correlation with the conditions of their crystallisation or transformation in the earth crust. Close structural relations in the row: lipscombite – barbosalite – trolleite – tavorite, are analyzed in order to unterstand the nature of paragenetic associations between these minerals or their analogues (Fe-trolleite).
The P21/m ↔ C2/m phase transition in amphiboles: new data on synthetic Na(NaMg)Mg5Si8O22F2 and the role of differential polyhedral expansion
Authors: Cámara Fernando , Oberti Roberta , Casati Nicola
Published: February 2008

The P21/m ↔ C2/m displacive phase transition has been studied on a synthetic amphibole with unit formula ANa0.90
B(Na0.92Mg1.08)C(Mg4.98V0.02)TSi8O22
O3F2. The evolution of the unit-cell parameters and of the intensities of a set of super-lattice reflections was monitored in the T range 100–944 K. Polynomial fitting of a 24 Landau potential to the evolution of the order parameter with T yielded a critical temperature (T
c) of 395 ± 5 K (398 ± 6 when considering low-T saturation of the order parameter), and Landau coefficients compatible with second-order transition. The values of T
c and the coefficients for the phase transition obtained in this work are compared to those previously obtained for synthetic ANa0.83
B(Na0.83Mg1.17)CMg5
TSi8O22
O3(OH)2 and to other data available in the literature. The substitution of OH by F at the O(3) site does not change the character of the transition, but decreases the T
c by at least 132 K, showing that the size of the M(4) polyhedron is not the only significant factor, and that the size of the octahedra and/or their different thermal expansion also play a role. Single-crystal structure refinements done at 100, 160, 220, 280, 340, 406, 514, 621, 729, 836 and 944 K allowed monitoring the changes in the structure and in the shape of electron density, which occur approaching the transition and during further heating. Mean thermal expansion coefficients for the different polyhedra in the structure were calculated for the high-T
C2/m phase, and are compared with those of other amphiboles with 5 Mg atoms per formula unit at the C-sites. The presence of F significantly affects both cation ordering within the A cavity and the thermal expansion along the b and c edges.
Does porous mean soft? On the elastic behaviour and structural evolution of zeolites under pressure
Authors: Gatta G. Diego
Published: February 2008

This is a comparative study on lattice compressibility, pressure (P)-induced structural deformation mechanisms and influence of the framework and extra-framework content on the elastic behaviour of zeolites, based on previously published data obtained by in situ HP-single crystal and powder diffraction experiments. The elastic data of zeolites reported so far allow us to infer that: 1) the peculiar characteristics of the zeolitic structure, with large channels and a flexible framework built of rigid units (i.e. the tetrahedra), implies that the main deformation mechanisms at high-pressure (HP) are controlled by rigid (Si,Al)O4-tetrahedral tilting; 2) the structural rearrangement at HP is mainly driven by framework geometry and its topological symmetry; 3) the compressibility of zeolites appears not to be directly related to the microporosity, represented by the “framework density”; 4) the elastic parameters available for natural zeolites demonstrate that microporosity does not necessarily imply high compressibility. Several zeolites appear to be less compressible than many rock-forming minerals. A high compressibility is generally expected for open-framework structures due to the tetrahedral tilting, which produces inter-tetrahedral angle variations and accommodates the effect of pressure. However, the bonding between the host zeolitic framework and the stuffed guest species (cations and H2O molecules) affect the overall compression behaviour, making this class of porous material unexpectedly less compressible than other silicates.
A Simulator-Based Tool That Assesses Pediatric Resident Resuscitation Competency
Authors: Brett-Fleegler Marisa B. , Vinci Robert J. , Weiner Debra L. , Harris Sion Kim , Shih Mei-Chiung , Kleinman Monica E.
Published: February 2008

BACKGROUND. Competency in pediatric resuscitation is an essential goal of pediatric residency training. Both the exigencies of patient care and the Accreditation Council for Graduate Medical Education require assessment of this competency. Although there are standard courses in pediatric resuscitation, no published, validated assessment tool exists for pediatric resuscitation competency.

OBJECTIVE. The purpose of this work was to develop a simulation-based tool for the assessment of pediatric residents' resuscitation competency and to evaluate the tool's reliability and preliminarily its validity in a pilot study.

METHODS. We developed a 72-question yes-or-no questionnaire, the Tool for Resuscitation Assessment Using Computerized Simulation, representing 4 domains of resuscitation competency: basic resuscitation, airway support, circulation and arrhythmia management, and leadership behavior. We enrolled 25 subjects at each of 5 different training levels who all participated in 3 standardized code scenarios using the Laerdal SimMan universal patient simulator. Performances were videotaped and then reviewed by 2 independent expert raters.

RESULTS. The final version of the tool is presented. The intraclass correlation coefficient between the 2 raters ranged from 0.70 to 0.76 for the 4 domain scores and was 0.80 for the overall summary score. Between the 2 raters, the mean percent exact agreement across items in each domain ranged from 81.0% to 85.1% and averaged 82.1% across all of the items in the tool. Across subject groups, there was a trend toward increasing scores with increased training, which was statistically significant for the airway and summary scores.

CONCLUSIONS. In this pilot study, the Tool for Resuscitation Assessment Using Computerized Simulation demonstrated good interrater reliability within each domain and for summary scores. Performance analysis shows trends toward improvement with increasing years of training, providing preliminary construct validity.
Carbon Sequestration in Native Prairie, Perennial Grass, No‐Till, and Cultivated Palouse Silt Loam
Authors: Purakayastha T. J. , Huggins D. R. , Smith J. L.
Published: February 2008

Comparative assessments for evaluating soil organic C (SOC) and its characteristics were made at different soil (Palouse silt loam) depths (0–5, 5–10, 10–20, and 0–20 cm) among sites with seven contrasting management histories: conventional inversion tillage (CT) followed by no‐till (NT) for 4 (NT4) and 28 (NT28) yr; bluegrass (Poa pratensisL.) seed production for 9 yr followed by NT for 4 yr (BGNT4); a sequence of 10 yr NT, 3 yr CT, and 1 yr NT (NTR); CT followed by 11 yr perennial grass under the Conservation Reserve Program (CRP); long‐term >100 yr CT; and native prairie (NP). Overall ranking of SOC, particlulate organic C (POC), and microbial biomass C (MBC) at 0 to 20 cm was NP > NTR > NT4 = NT28 > CRP > BGNT4 = CT. Greater SOC, POC, and MBC in NTR than NT28 indicated that tillage rotation could result in more soil C sequestration, primarily by increasing C stocks in 5‐ to 20‐cm depths. The POC was labile in nature as it highly correlated with Cmin(r= 0.69,P< 0.01) and MBC (r= 0.86,P< 0.01) as well as SOC (r= 0.89,P< 0.01). We concluded that: (i) neither NT nor conversion to perennial vegetation would attain the SOC found in NP over 10 to 30 yr; and (ii) medium duration of NT (10 yr) combined with short intervals of CT (3 yr) followed by NT might increase SOC compared with continuous long‐term NT under annual cropping.
Soil Nitrogen Transformations Under Alternative Management Strategies in Appalachian Forests
Authors: Coates T. Adam , Boerner Ralph E.J. , Waldrop Thomas A. , Yaussy Daniel.A.
Published: February 2008

Once subject to frequent fire and strongly N limited, the forests of the Appalachian Mountain region of eastern North America have experienced almost a century of fire suppression, and changes in tree species composition, understory density and composition, and accumulations of detritus have paralleled the changes in fire frequency. In an effort to restore these ecosystems and reduce wildfire hazard, alternative management strategies (prescribed fire, mechanical fuel reduction, and a combination of both) were implemented at study sites in Ohio and North Carolina as part of the Fire and Fire Surrogate Network Study. As changes in N cycling resulting from these treatments could have potential negative impacts on forest health that might limit their usefulness as management alternatives, we monitored treatment effects on extractable total inorganic N (TIN), net N mineralization, net nitrification, and proportional nitrification during the growing season before treatment, the first growing season after treatment, and the third or fourth growing season after treatment. Mechanical treatment resulted in increases in extractable TIN, N mineralization, and nitrification during the first post‐treatment year in Ohio and TIN was greater in the mechanical treatment and the mechanical + fire treatment during the third post‐treatment year in North Carolina. Net N mineralization was reduced by fire alone in Ohio, but not in North Carolina. Nitrogen transformation rates were 2‐ to 10‐fold higher in Ohio than North Carolina, a difference that may partly result from of the ericaceous shrub understory present in North Carolina but not in Ohio. Impacts of these treatments on N transformations were modest and for the most part transient, and would therefore not eliminate these treatments as viable management strategies for wildfire hazard reduction or ecosystem restoration.
Dense Gas Flow in Volcanic Ash Soil: Effect of Pore Structure on Density‐Driven Flow
Authors: Hamamoto Shoichiro , Tokida Takeshi , Miyazaki Tsuyoshi , Mizoguchi Masaru
Published: February 2008

Unique physical properties of volcanic ash soils characterize the soil gas transport parameters of gas diffusivity and air permeability. Air permeability controls the density‐driven flow that has been recognized as one of the important phenomena for subsurface dense gas. In this study, one‐dimensional column experiments were conducted to investigate the effects of the pore structure of a volcanic ash soil on the density‐driven flow of a dense gas (isohexane). The results showed that the overall horizontal gas movement in Tachikawa loam (volcanic ash soil) and Toyoura sand (sand) used as reference materials was expressed by Fick's diffusion law. On the other hand, the vertical downward gas movements in Tachikawa loam were considerably enhanced by the occurrence of density‐driven flow, especially at high air contents (30–40%). Pore size distribution and pore structure analysis based on the tube model suggest that a greater volume of large pores (>0.01 cm) and a more continuous pore network led to the greater density‐driven flow in Tachikawa loam than in Toyoura sand.
Boron Adsorption by Soils as affected by Dissolved Organic Matter from Treated Sewage Effluent
Authors: Communar G. , Keren R.
Published: February 2008

Although it is well known that treated sewage effluent enhances trace elements and nutrient solubility in soil solution through their complexation with dissolved organic matter (DOM), no information is available yet for B. The main purpose of this study was to evaluate the effect of DOM with B and native soil organic matter (OM) on B adsorption by soils. Batch equilibrium studies were conducted to measure the B adsorption by DOM (pH 7.7) that was selected from a municipal sewage plant. Effluent DOM was found to have a low affinity for the soils and its application resulted in a release of native soil OM into solution. The OM release was enhanced significantly by an increase in soil mass/solution volume ratio and effluent DOM concentration. The B adsorption capacity of DOM (294–333 mg kg−1) was less than that found for different humic acids (583–2235.6 mg kg−1). Nevertheless, the presence of DOM reduced the free‐B concentration in solution due to formation of B–DOM complexes. As the total DOM concentration increased, the slope of the isotherms for B adsorption by soil decreased. All the B adsorption isotherms obtained for the different DOM concentrations merged into one isotherm, however, when free‐B solution concentration was taken into consideration. The results suggest that the B–DOM complex did not interact with the soil.
A Micro-fluidic System for the Evaluation of Blood Compatibility of Polymers
Authors: Minelli C. , Kikuta A. , Yamamoto A.
Published: February 2008

We present a new technique for the evaluation of polymer blood compatibility that makes use of a microchannel
array flow analyzer and we describe and characterize the flow dynamics of this instrument. The blood compatibility
of four polymers is quantitatively and qualitatively assessed and the results discussed. The blood is allowed to flow
through the channels of a polymer coated micro-fluidic chip under adjustable pressure. The chip surface is investigated
using optical microscopy during the blood flow and by scanning electron microscopy afterwards. Polymers known for
having good blood compatibility exhibited higher flow rate values. Platelets were observed adhering, aggregating and obstructing
the channels of the chips coated with polymers known for having poor blood compatibility. This technique has
remarkable qualities such as a small blood volume requirement for material tests (100 μL), tuneable flow regimes and the
use of human blood.
Assessment of Different Expression Strategies for the Production of a Recombinant Lipoprotein Vaccine in Plants
Authors: Hennig Anna , Reinders Yvonne , Giritch Anatoli , Reinders Jörg , Warzecha Heribert
Published: February 2008

The ability of plants to serve as a production system for bacterial lipoprotein vaccines has been investigated.
First, the effect of high-level expression of the Borrelia burgdorferi outer membrane protein A (OspA), a prototype vaccine
against Lyme disease, has been examined by a proteomics approach. Analysis by 2D-PAGE of wild type tobacco
plants and transplastomic plants accumulating recombinant OspA showed no apparent differences in protein pattern except
for OspA. However, presence of the bacterial signal sequence limits transgene accumulation. As an alternative approach
OspA was produced in Nicotiana benthamiana plants by transient expression via a deconstructed tobacco mosaic
virus-based system. While rapid expression of OspA could be achieved, no palmitoylation occurred with the genuine bacterial
sequence. In contrast, modification of the N-terminus with an eukaryotic sequence motif resulted in palmitoylation
of OspA. This study shows that plants provide multiple expression strategies and could serve as a versatile production
platform for recombinant lipidated subunit vaccines.
Acute and Chronic Impact of Dynamic Exercise on Arterial Stiffness in Older Hypertensives
Authors: Aizawa Kunihiko , Petrella Robert J
Published: February 2008

Arterial stiffness increases with ageing and hypertension. Regular physical activity has been recommended as an important management component of hypertension. The purpose of this study was to examine the acute impact of maximal dynamic exercise and the effect of 20 weeks of aerobic exercise on arterial stiffness of the carotid and brachial arteries in older hypertensives. Nine previously sedentary and treated older hypertensives (2 men and 7 women, age 68.2 ± 5.4 yrs) performed maximal treadmill exercise to volitional fatigue while arterial stiffness indices (arterial distensibility and β stiffness index) were measured prior to, immediately (about 10 min) following, and 24 h following maximal exercise. These measurements were repeated following 20 weeks of moderate intensity aerobic exercise training. Maximal exercise had no impact on arterial stiffness indices immediately and 24 h following exercise intervention. Following 20 weeks of training, arterial stiffness indices remained unchanged at rest and following maximal exercise. These data show that, in older hypertensives, 1) acute maximal dynamic exercise had no impact on arterial stiffness of the carotid and brachial arteries, and 2) 20 weeks of moderate intensity aerobic exercise training failed to modify arterial stiffness.
Selenium Status in Heifers, Late Pregnancy Cows and Their Calves in the Šumava Region, Czech Republic
Authors: Slavík P. , Illek J. , Zelený T.
Published: February 2008

The objective of this study was to ascertain selenium status in beef cattle in different stages of production in the Šumava region. In the region, blood collections and analyses for selected metabolic variables were performed in 54 animals in different production stages (18 heifers, 18 cows in late pregnancy and 18 calves aged 3 weeks on the average). Three herds were studied. The selenium status was determined both directly by measuring serum selenium (Se) contents and indirectly by measuring glutathione peroxidase (GSH-Px) activity in whole blood. The mean serum selenium concentration in all the animals under study (n = 54) was 30.6 μg/l +/- 2.91, and mean GSH-Px activity was 167.01 μkat/l +/- 92.39. In heifers, mean serum selenium concentration was 34.81 μg/l +/- 13.84; mean GSHPx activity was 186.96 μkat/l +/- 112.15. In late pregnancy cows, mean serum selenium concentration was 26.58 μg/l +/- 8.01, mean GSH-Px activity was 94.55 +/- 35.72 μkat/l. In calves, mean serum selenium concentration and GSH-Px activity were 30.41 μg/l +/- 12 and 219.54 μkat/l +/- 64.41, respectively. There was a statistically significant difference between the heifers and late pregnancy cows in both variables under study. However, between the late pregnancy cows and the calves, only the difference in GSH-Px activity was significant. The results indicate severe Se deficiency in the animals under study. It means apart from other things that mineral licks used did not provide enough minerals to meet the basic requirements of the animals.
Changes in Blood Values of Glucose, Insulin and Inorganic Phosphorus in Healthy and Ketotic Dairy Cows after Intravenous Infusion of Propionate Solution
Authors: Djoković R. , Šamanc H. , Nikolić Z. , Bogosavljević S. Bošković
Published: February 2008

The aim of the present study was to determine the degree of blood glucose utilization by peripheral tissue on the basis of changes in blood concentrations of glucose, insulin and inorganic phosphorus in healthy (n = 10) and ketotic cows (n = 10) after intravenous infusion of propionate solution. Blood samples were taken in both groups of examined cows at the following time intervals: just before (time 0) and 8, 30, 60, 120, 180, 240 and 480 min after the intravenous infusion of 1.84 mol l-1 solution of propionate in the amount of 1 ml kg-1 of body weight. Glucose and insulin blood serum values in both groups of cows increased significantly within 120 min of the experiment (p < 0.05). Significantly lower values (p < 0.05) of glucose in blood of ketotic cows, compared to the blood value of glucose in healthy cows were established within 30, 60, 120 and 240 min of the experiment, as a consequence of the decreased gluconeogenic ability of the liver in the ketotic cows. Significantly lower values (p < 0.05) of insulin in blood of ketotic cows in comparison with healthy ones were established within 240 and 480 min of the test. That indicates that the ability of beta cells of the endocrine pancreas to release insulin is reduced in cows suffering from ketosis. After intravenous administration of propionate, it was established that values of inorganic phosphorus were reduced in blood in both groups of cows after 8, 30, 60, 120, 240 and 480 min. Within 480 min of the test there was a significant decrease (p < 0.05) in blood value of inorganic phosphorus in ketotic cows in comparison with healthy ones. This is linked with the active entry of glucose into glucolytic pathway of peripheral tissues. It can thus be concluded that there is a higher degree of blood glucose utilization by peripheral tissues in ketotic cows.
Postruminal Delivery System for Amino Acids and Proteins in Cattle
Authors: Sýkora T. , Rabišková M. , Třináctý J. , Vetchý D. , Häring A. , Dvořák P.
Published: February 2008

The purpose of this experiment was to develop an effective postruminal transport system (PTS) with a high content of suitable vegetable proteins and amino acids. PTS serves for nutrient delivery to the abomasum and small intestine of dairy cows in order to increase the milk yield. Direct addition of proteins and amino acids to the diet is not useful as the ruminal microbes will utilize active substances before they reach absorption sites in the small intestine. PTS has several advantages, e.g. a possibility of the direct application in a food, low cost, and nutritional and therapeutical improvement. PTS consists of a core (pellets, small tablets) and a coating, which protects the core against the environment of rumen and enables to release the core content in the environment of abomasum and small intestine. Lenticular tablets - cores of PTS were prepared by wet granulation method and compression. Qualitative indicators of tablets (average weight, weight uniformity, hardness, friability, disintegration time) were determined according to valid Czech and European Pharmacopoeias. Cores were subsequently coated with several types of coating - ethylcellulose, stearic acid and pH sensitive polymer poly-(2-vinylpyridine-co-styren), alone or in combination of various rates. Nine samples of coated protein tablets exhibiting appropriate characteristics in vitro were prepared. The presence of the pH sensitive polymer at least in 10% concentration of the coating and the coating amount of 9.0 to 12.6% per tablet were necessary to ensure the requested PTS properties.
Influences of Different Milk Yields of Holstein Cows on Milk Quality Indicators in the Czech Republic
Authors: Janů L. , Hanuš O. , Frelich J. , Macek A. , Zajíčková I. , Genčurová V. , Jedelská R.
Published: February 2008

The milk yield (MY) is an important economic and health factor closely connected with the health status of dairy cows, their reproduction performance, longevity and milk composition and properties (MIs). The differences within MIs between high yielding herd (Group 1; 10 282 kg per lactation) and three herds with average MY (Group 2; 7 926 kg) were tested. The files with 96 and 290 milk samples were collected in summer and winter feeding seasons and well balanced in lactation factors. Group 1 had higher genetical value, better nutrition and was milked three times per day and its MY was higher by 30% (P < 0.001). among 23 milk indicators (MIs) under study only a few MIs (30.4%) were influenced (P < 0.05): somatic cell count (SCC); urea (U); acetone (AC); pH acidity; alcohol stability; curd firmness; the ratio of urea nitrogen in non-protein nitrogen (URN). Except for U, these changes were less important. Protein spectrum was not affected (P > 0.05). The U was probably higher due to higher loading of the nitrogen nutrition (4.27 > 3.57 mmol l-1) in MY 1. Surprisingly, SCC was higher (112 > 81 103 ml-1) and AC lower ((0.0374) 0.0250 < (0.0577) 0.0336 mmol l-1) in Group 1. Both the MIs did not indicate problems of the health status. An indicator of energy nutrition balance as fat/protein ratio was not influenced (1.15 ± 0.24 versus 1.16 ± 0.23; P > 0.05), despite the large difference between MY 1 and 2. URN was higher in MY 1 (46.5 > 39.1%) due to more efficient nutrition, like in U. The high MY had no negative impacts on MIs with well balanced nutrition of Holstein cattle.
Comparison between Xylazine-Tiletamine-Zolazepam and Fentanyl-Tiletamine-Zolazepam Anaesthetic Combinations on Plasma Oxidative Status in Sheep
Authors: Aydilek N.
Published: February 2008

It is important to determine varying effects of anaesthetics agents. One of the adverse effects of general anaesthetics are the exogenous sources of reactive oxygen species. In this study, the effects of xylazine-tiletamine-zolazepam (XTZ) and fentanyl-tiletamine-zolazepam (FTZ) combinations on plasma oxidant-antioxidant indicators were compared in sheep. Ten ewes received two different anaesthetic combinations in a ten-day interval. XTZ group was injected with xylazine and tiletamine-zolazepam. FTZ group was injected with fentanyl and tiletamine-zolazepam. Blood samples were collected before and at the 30, 60, 120 min, 24 h and 3 days after anaesthesia. Both anaesthetic regimens caused an increase in malondialdehyde (MDA) concentrations in plasma. The MDA concentrations at 60, 120 min and 24 h in the XTZ group were significantly higher than in the FTZ group. Glutathione (GSH) concentration at 30, 60, 120 min and 24 h was significantly lower than baseline values in XTZ group, while there was only a decrease at 120 min in the FTZ group. GSH concentrations in the XTZ group were significantly lower at 60 and 120 min compared with the FTZ group. Beta carotene concentration was decreased at 120 min and 24 h in the XTZ group, while it decreased only at 120 min in the FTZ group. Glutathione peroxidase (GSH-Px) and catalase (CAT) activities decreased at 120 min and 24 h only in the XTZ group. There were no significant differences in β-carotene concentration, activities CAT and GSH-Px activities between groups. In conclusion, both XTZ and FTZ anaesthetic regimens induced oxidative stress in sheep. XTZ combination has more detrimental effect than FTZ combinations on particularly MDA and GSH concentrations. Therefore, FTZ anaesthetic combination is considered to be more suitable for sheep anaesthesia, due to less deteriorating effects on oxidant/antioxidant balance.
Evaluation of Immunoglobulin Production during Tularaemia Infection in BALB/c Mouse Model
Authors: Pohanka M.
Published: February 2008

The chromatographic technique was used for assay of time-dependent content of antibodies in mice BALB/c infected by tularaemia. The assay was consequently performed on two types of chromatographic sorbents. The first was commercial CBindTM specific for serum immunoglobulins IgM, IgG and IgA. The second was originally prepared sorbent including protein G covalently bound on EnzacrylRAH particles. This sorbent has specificity for immunoglobulin IgG and its subclasses only. Finally, mass concentration of immunoglobulins in serum was determined. Two curves expressing time behavior of immunoglobulin content (immunoglobulin mass concentration vs. days after immunization) were used for finding the proper mathematical function. The function found was sigmoid; subsequently, appropriate constants needed for function solution were evaluated.
Impact of Crude Protein Intake in Last 14 Days of Pregnancy on Puerperium, Piglet Loss Prior to Weaning and Subsequent Reproduction of Sows
Authors: Tydlitát D. , Vinkler A. , Czanderlová L.
Published: February 2008

The impact of feed containing 13%, 15%, 18% and 21% of crude protein fed to groups of sows (marked A, B, C and D) from Day 100 of pregnancy until farrowing on puerperium, piglet loss prior weaning, fat depot differences, onset of reproductive activities after weaning, subsequent mating and the progesterone concentrations were studied. in groups A and B there were no puerperium disorders. Piglet loss before weaning reached 16.12 and 18.04% of all born piglets, 90% of sows became pregnant after the 1st insemination. in groups C and D the overall loss of all born piglets before weaning was 24.86 and 28.91%. The differences to groups A and B were significant (p < 0.05). Significant differences (p < 0.05) were found between groups A, B and C, D in number of animals exceeding body temperature of 39.6 °C. Puerperium disorders and MMA syndrome were detected in 50% of the sows in group C and 80% in group D. The conception rate after the 1st insemination was 80% (group C) and 60% (group D). reduction in the back fat thickness was at the boundary of statistical significance (p < 0.1) in groups C and D as compared to groups A and B. There was no difference in the onset of heat after weaning between the groups. in progesterone concentrations, significant differences (p < 0.05) were found between groups A and D on Day 14 after weaning. We demonstrated a negative impact of high crude protein intake in last 14 days of pregnancy in sows on puerperium and piglet loss prior to weaning.
Effect of L-Carnitine Supplementation on Boar Semen Quality
Authors: Jacyno E. , Kołodziej A. , Kamyczek M. , Kawęcka M. , Dziadek K. , Pietruszka A.
Published: February 2008

The effect of addition of L-carnitine on boar semen quality was studied in 5 Pietrain boars at age 1.5 - 2.0 years. The boars received 500 mg of L-carnitine per day for 5 weeks. During this period, their ejaculates were collected once a week and evaluated for quality. The control ejaculates had been collected before the application of L-carnitine. It was found that the addition of L-carnitine to the boars' feed had a positive effect on the quality of boar semen. The total ejaculate volume and sperm-rich fraction volume increased by 11% and 10%, respectively; the total ejaculate sperm count increased by 11.5% (P < 0.05). Also, the number of spermatozoa with major and minor morphological changes decreased and seminal plasma activity of AspAT was significantly reduced (P < 0.01). Sperm concentration and motility, as well as normal acrosome sperm percentage, did not increase considerably. The positive effect of L-carnitine on boar semen quality was observable as early as after one week of its application.
Two Protocols of Cryopreservation of Goat Semen with the Use of Computer-Assisted Semen Analysis System
Authors: Kozdrowski R. , Dubiel A. , Bielas W. , Dzięcioł M.
Published: February 2008

The objective of the study was a comparison of two protocols of goat semen cryopreservation with the use of computer-assisted semen analysis system. Twenty ejaculates obtained with electroejaculation method were assessed. Each ejaculate was divided in half and frozen according to two protocols. In protocol I semen was centrifuged in order to remove its plasma and diluted in Tris buffer extender containing glucose, citric acid and glycerol with 20% addition of egg yolk. Protocol II did not include removal of plasma and the extender contained 1.5% egg yolk. It was shown that the removal of semen plasma improved motility of goat spermatozoa following freezing/thawing with respect to the following motility indicators: motility, average path velocity, amplitude of lateral head displacement at p < 0.05, and straight velocity, straightness and linearity at p < 0.01. In conclusion, the removal of semen plasma through centrifugation improved motility properties of goat semen following the freezing/thawing procedure.
Effect of Ovarian Steroids on Colonic Epithelial Cell Proliferation and Apoptosis in Rats
Authors: Altunbas K. , Yagci A. , Bulbul A. , Sevimli A. , Özdemir V.
Published: February 2008

The aim of this study was to investigate the effects of steroid hormones on proliferation and apoptosis in the colon crypt epithelium. The research was conducted on adult ovariectomized (Ovx) rats (Sprague Dawley). Ovx rats were injected for 15 days with 0.2 ml of sesame oil (control; C), or 17β-oestradiol (10 μg/d; E), or progesterone (2 mg/d; P), or E + P. Proliferative activity in the colon was assessed by using proliferating cell nuclear antigen (PCNA) antibody. The proliferation index (PI), the number of PCNA positive cells divided by the total number of cells counted in the crypt column multiplied by 100, was calculated. PI was lower in the hormonetreated groups, especially in group P compared to that in group C. The apoptotic index (AI), the mean number of apoptotic cells, was detected by active caspase 3 immunoreactivity per crypt in the colon. AI was lower in the colon crypt epithelium of group E than that of the other groups. However, AI in the colon crypt epithelium in groups P and E + P was higher than that of both group E and group C. In addition, the colon crypt size (the number of epithelial cells lining one side of 10 well-oriented, longitudinally cut crypts) was considerably lower in group E than that of the other groups. In conclusion, we showed that the decrease of AI in group E was balanced by progesterone; the decrease of PI in group P was also depressed by oestrogen.
Etoricoxib in the Prevention of Rat Mammary Carcinogenesis
Authors: Orendáš P. , Ahlers I. , Kubatka P. , Ahlersová E. , Bojková B. , Kassayová M. , Friedmanová L. , Kisková J. , Ďatelinka I. , Starostová M.
Published: February 2008

Several experimental studies suggest that non-steroidal antiinflammatory drugs have chemopreventive effects in mammary carcinogenesis. In this study, tumour suppressive effects of a selective inhibitor of cyclooxygenase-2 (COX-2) etoricoxib in the prevention of N-methyl-Nnitrosourea (NMU)-induced mammary carcinogenesis in Sprague-Dawley rats were evaluated. Etoricoxib was administered in the diet, at two concentrations: 1) 0.01 mg/g (ETO 0.001%) and 2) 0.025 mg/g (ETO 0.0025%). Although the chemopreventive effects were not statistically significant, remarkable tumour suppressive effects with the concentration of ETO 0.0025% were recorded. The incidence decreased by 4.31% and tumour frequency per group decreased by 6.67% when compared to the control group. Latency (the period from carcinogen administration to the first tumour appearance) increased by 7.28% in dose-dependent manner. The results of our experiments point to dose-dependent tumour suppressive effects of a higher concentration of etoricoxib (ETO 0.0025%) when compared to the control group. They suggest that higher etoricoxib concentrations may enhance its tumour suppressive effects.
Prevalence and Characteristics of Streptococcus canis Strains Isolated from Dogs and Cats
Authors: Lysková P. , Vydržalová M. , Královcová D. , Mazurová J.
Published: February 2008

To determine the prevalence of Streptococcus canis in dogs and cats, a total of 926 swabs were examined bacteriologically in the period from 2003 to 2005. Eighty-six isolates obtained from various anatomical locations were further characterized for their phenotypic properties. The most frequently isolated biotype produced phosphatase, leucine amidopeptidase, arginine dihydrolase, alpha-D- and beta-D-galactosidase and fermented lactose and ribose. Additional identification by species-specific amplification of the 16S-23S rRNA intergenic spacer region was consistent with S. canis. All isolates were susceptible to penicillin G and ampicillin. The least effective antimicrobial agent was found to be tetracycline (only 33.8% of susceptible strains).
Behavioural Traits of Four Dogs Breeds in Czech Households
Authors: Baranyiová E. , Holub A. , Tyrlík M.
Published: February 2008

Our study was aimed at the behavioral aspects of coexistence with people of four canine breeds in Czech households. From the original set of data in 305 earlier analyzed dogs we selected 89 animals, i.e. those concerning the four most numerous breeds, (34 Dachshunds, 16 Schnauzers, 23 German Shepherd Dogs and 16 Poodles), and compared their 85 behavioural traits and interactions with their household members. The results were evaluated using the chi-square test. Dogs belonging to these four breeds differed significantly in only 28 (32.9%) of the indicators under study. Except for a few German Shepherd Dogs all members of our group were considered to be companion animals and household members. They were no longer used as earth dogs or hunting, guarding/herding dogs. Breed characteristics were taken into consideration only exceptionally. People kept them for pleasure and not for their original skills, once carefully selected for and modified. On the contrary, these skills became undesirable in urban environment. Despite that, dog breeds are designated by their original functions and use, even though the anthropomorphic selection pressures continue. People want their dogs to adapt more and more to the intimate co-existence in rural and urban environments. Thus, canine behaviour is under massive selection pressures.
Zinc and Cadmium Toxicity Using a Biotest with Artemia franciscana
Authors: Nováková J. , Daňová D. , Strišková K. , Hromada R. , Mičková H. , Rabišková M.
Published: February 2008

Of the various toxic elements heavy metals, particularly cadmium, lead, mercury and zinc, occur frequently in the environment due to their relatively high industrial use. While the toxicity of individual substances is usually well known, information about their mutual interactions is relatively scarce. In animal experiments the prevailing trend is to substitute higher vertebrates with biotests of the 2nd generation. Our experiment focused on observation of the effect of combinations of ZnSO4.7H2O and CdCl2.2H2O on lethality to Artemia franciscana. The aim of the study was to observe the synergistic or antagonistic effects of these two metals. Depending on concentration, cadmium may increase or decrease the toxicity of zinc. at higher concentrations of CdCl2.2H2O exceeding 100 mg l-1 one can observe obvious synergistic toxic effects of both the substances. Our observations allowed us to conclude that the use of optimum, relatively low concentrations of cadmium (up to 50 mg l-1 CdCl2.2H2O) results in a significant decrease in lethality to Artemia franciscana caused by ZnSO4.7H2O at concentrations of 50, 100 a 250 mg l-1.
Polarization conversion by dielectric subwavelength gratings in conical mounting
Authors: Passilly Nicolas , Karvinen Petri , Ventola Kalle , Laakkonen Pasi , Turunen Jari , Tervo Jani
Published: February 2008

Subwavelength dielectric gratings are examined in total-internal-reflection configuration. It is demonstrated experimentally that such elements, fabricated in TiO2, can perform full polarization conversion from incident TE to TM with nearly 100% efficiency. The dependence of the polarization conversion on the angle of incidence is analyzed. Rigorous diffraction theory is used to cross check the experimental results.
Foot and Ankle Fellowship Training: A National Survey of Past, Present, and Prospective Fellows
Authors: Schiller Jonathan R. , DiGiovanni Christopher W.
Published: February 2008

Background: Surgical specialties have become increasingly subspecialized. An expanding demand for foot and ankle care administered by trained specialists has driven the need for foot and ankle-trained orthopaedic surgeons. This survey was designed to elucidate the reasons why residents choose a career in foot and ankle surgery. Methods We conducted a national, anonymous, 11-question survey of past, present, and prospective foot and ankle fellows (156 mailed). The questions focused on trying to understand the decision-making process in pursuing a foot and ankle fellowship, and assessing the overall satisfaction of this career choice. Questionnaires were returned within one month of their mailing. Results: We achieved a 40% overall response rate. The fellow's relationship with their residency program's foot and ankle specialist was the primary catalyst for pursuing foot and ankle as a career. Nearly all respondents were satisfied with their decision to do a foot and ankle fellowship, though some were disappointed early in practice with remuneration, practice competition, and patient dissatisfaction. American Orthopaedic Foot and Ankle Society (AOFAS) membership was nearly unanimous. Conclusion: The relationship established between a resident and his or her foot and ankle mentor while in training appears to have the greatest impact on pursuing foot and ankle surgery as a career. Once in practice, few trained fellows regret their decision, and few report disappointments not similarly voiced by other orthopaedic subspecialties. Based on this data, the importance of a foot and ankle rotation elective during orthopaedic residency and the impact subspecialty service attendings have on resident interests and career choices seem clear.
Minimally Invasive Method of Harvesting the Flexor Digitorum Longus Tendon: A Cadaver Study
Authors: Panchbhavi Vinod Kumar , Yang Jinping , Vallurupalli Santaram
Published: February 2008

Background: The flexor digitorum longus (FDL) tendon is harvested for use in the reconstruction of dysfunctional adjacent tendons such as the posterior tibial and the Achilles tendons. The approach to harvest the FDL tendon in the midfoot region is through an incision along the medial border of the foot. This approach involves dissection quite deep in the foot across neurovascular structures in the vicinity placing them at risk. The purpose of this cadaver study was to test the feasibility and safety of a minimally invasive technique, and also to define the relevant topographical surface and deeper surgical anatomy. Methods: In 83 cadaver feet, the FDL tendon was harvested proximally in the hindfoot after it was cut through a small plantar incision in the midfoot. All the tissues superficial to the FDL tendon were then reflected to check for damage to the adjacent neurovascular structures. Measurements were obtained to define the location of the point of division of the FDL tendon in relation to the plantar surface of the foot and the adjacent neurovascular structures. Results: In all of the 83 feet it was possible to harvest the FDL using this technique. In 11 feet (13.25%), a connecting band to the flexor hallucis longus tendon (FHL) required division. No damage was apparent to the adjacent neurovascular structures. The FDL division was located topographically on the plantar surface of the foot, approximately midway between the back of the heel and the base of the second toe and at this midpoint, about two-thirds of the width medially from the lateral border of the foot. Conclusions: The FDL tendon can be harvested in the hindfoot after its division through a small plantar incision in the midfoot. Surface anatomy guides placement of the plantar incision over the FDL division. Clinical relevance: The plantar approach when compared to the medial approach for harvesting the FDL tendon in the midfoot may be associated with a smaller incision, minimal dissection, lesser risk to adjacent neurovascular structures and lesser morbidity.
A Constant Radiological Sign in Bosworth's Fractures: “The Axilla Sign”
Authors: Khan Fahim , Borton David
Published: February 2008

We describe a rare ankle fracture pattern called “the Bosworth fracture,” originally described in 1947. A Bosworth fracture has been defined as a fixed posterior fracture-dislocation of the distal part of the fibula in which the proximal fibular shaft fragment locks behind posterior tibial tubercle. This fracture is frequently irreducible by closed means. Severe early and late morbidity, resulting from failure to identify and promptly treat this fracture pattern, have been reported. We describe a new radiographic sign seen on anterior-posterior mortise radiographic view showing cortical density in the axilla of the medial tibial plafond: “the Axilla sign.” This feature was also noted on the radiographs of other case reports with this unique injury. The presence of this sign should alert the treating surgeon to a possible Bosworth fracture.
A Comparison of Radiation Exposure with the Conventional versus Mini C Arm in Orthopedic Extremity Surgery
Authors: Shoaib Amer , Rethnam Ulfin , Bansal Ravi , De Anirban , Makwana Nilesh
Published: February 2008

Background: The mini C arm is a mobile fluoroscopic device for use on extremities. It has been reported that this type of device has several advantages over a conventional C arm, the most important of which is a decreased level of radiation scatter to the surgeon. Methods: This was a case control study. The radiation dose to the surgeon was calculated from the radiation exposure time and distance from the x-ray emitter. Cases using the mini C arm were compared with operation-matched controls that had the identical procedure performed with a conventional C arm. Results: The mini C arm caused statistically less radiation scatter to the surgeon, but there was no statistically significant difference in the radiation exposure to the patient. This was despite a significantly larger number of exposures with the mini C arm for each operation type. Conclusions: The mini C arm should be used in preference to the conventional C arm for extremity surgery, if both are available.