DFT and MD simulation supplemented experiments for isotopic fractionation of zinc compounds using a macrocyclic crown ether appended polymeric resin.

Isotope effect is a quantum mechanical phenomenon and thus poses a challenge for the separation of isotopes of an element of interest, especially for heavy elements. Isotopic fractionation of zinc is also quite difficult and challenging but is necessitated due to various applications of its isotopes ranging from nuclear medicine to nuclear power reactors. Here, we developed the dibenzo-18-crown-6 (DB18C6) ether-functionalized poly(methacrylic acid) (PMA) resin by exploiting the ion and isotope recognition ability of the crown ether using DFT/MD simulations followed by experiments for isotopic fractionation of zinc. The PMADB18C6 adsorbent was prepared and suitably characterized. Both computational and experimental findings demonstrate that the adsorption and isotope separation of zinc with PMADB18C6 are due to the molecular recognition effect of the "O" dipole of the crown ether. Furthermore, both MD simulations and experiments suggest Langmuir type adsorption isotherms. The adsorption of Zn2+ ions on the PMA resin is predicted to be endothermic, whereas it is exothermic on the PMADB18C6 resin, as revealed from the experimentally observed enthalpy change. A small scale fixed bed column study was demonstrated to test the scale-up application. The values of the experimental separation factors: 1.0013 for 66/64 and 1.0027 for 68/64 confirm the computationally predicted results of 1.00088 and 1.0010, respectively, thus establishing the combined strength of the theory and experiments for the identification of efficient fractionating agents for a complex quantum isotope effect which eventually helps in planning further experiments in view of medicinal and technological applications of zinc isotopes.

Magnetic field effect on the energy levels of an exciton in a GaAs quantum dot: Application for excitonic lasers.

The problem of an exciton trapped in a Gaussian quantum dot (QD) of GaAs is studied in both two and three dimensions in the presence of an external magnetic field using the Ritz variational method, the 1/N expansion method and the shifted 1/N expansion method. The ground state energy and the binding energy of the exciton are obtained as a function of the quantum dot size, confinement strength and the magnetic field and compared with those available in the literature. While the variational method gives the upper bound to the ground state energy, the 1/N expansion method gives the lower bound. The results obtained from the shifted 1/N expansion method are shown to match very well with those obtained from the exact diagonalization technique. The variation of the exciton size and the oscillator strength of the exciton are also studied as a function of the size of the quantum dot. The excited states of the exciton are computed using the shifted 1/N expansion method and it is suggested that a given number of stable excitonic bound states can be realized in a quantum dot by tuning the quantum dot parameters. This can open up the possibility of having quantum dot lasers using excitonic states.

Density functional theoretical study on the preferential selectivity of macrocyclic dicyclohexano-18-crown-6 for Sr⁺² ion over Th⁺4 ion during extraction from an aqueous phase to organic phases with different dielectric constants.

The preferential selectivity of dicyclohexano-18-crown-6 (DCH18C6) for bivalent Sr(+2) ion over tetravalent Th(+4) ion was investigated using generalized gradient approximated (GGA) BP86 and the hybrid B3LYP density functional, employing split valence plus polarization (SV(P)) and triple-zeta valence plus polarization (TZVP) basis sets in conjunction with the COSMO (conductor-like screening model) solvation approach. The calculated theoretical selectivity of DCH18C6 for Sr(+2) ion over Th(+4) ion was found to be in accord with the selectivity for Sr(+2) ion over Th(+4) ion observed when performing liquid-liquid extraction experiments in different organic solvents. While 1:1(M:L) stoichiometric complexation reactions can be used to predict the preferential selectivity of Sr(2+) ion over Th(4+) ion, the results obtained are not consistent with the experimental results observed upon increasing the dielectric constant of the solvent. The calculated theoretical gas-phase data for the free energy of complexation, ∆G, fail to explain the selectivity for Sr(+2) ion over Th(+4) ion. However, when 1:2 (M:L) stoichiometric complexation reactions (reported in previous X-ray crystallography studies) are considered, correct and consistent results for the selectivity for Sr(+2) ion over a wide range of dielectric constants are predicted. The distribution constant for Sr(2+) and Th(4+) ions was found to gradually increase with increasing dielectric constant of the organic solvent, and was found to be highest in nitrobenzene. The selectivity data calculated from ∆∆G ext are in excellent agreement with the results obtained from solvent extraction experiments.

How to improve the quality of a disease management program for HIV-infected patients using a computerized data system. The Saint-Antoine Orchestra program.

OBJECTIVES: The emergence of non-AIDS-related events in the HIV-infected population experiencing a longer life expectancy implies the implementation of a comprehensive approach of HIV clinical management through better access to care, prevention, and early diagnosis of co-morbidities. METHODS: The Orchestra program is a computer-assisted HIV care and support tool implemented since December 2004 in the outpatient clinic of a University Hospital set in Paris, France. The intervention aims at improving access to HIV information care and support specifically targeted five areas of actions: cardiovascular risk factors; gynecological follow-up; anti-hepatitis B virus (HBV) vaccine coverage; sexuality and prevention of sexually transmitted infections; and compliance to antiretrovirals. The impact of this program was examined prospectively on a "before-after" basis after a two-year implementation. RESULTS: In the two-year period, 1717 patients were regularly followed. The level of the database information significantly increased in time (low density lipoprotein (LDL) cholesterol and glycemia were informed in 74% of patients at inclusion versus 95% at two years, and 83% versus 97%, p < 0.001, respectively). The number of targeted interventions was also higher. For eligible women, papanicolaou smears and mammography were prescribed in 52% of cases after intervention, versus 44% at inclusion, p0.04 and 83% versus 50%, p < 0.001, respectively. Indicators of care eventually improved significantly. Initially 72% non-adherent patients declared to be adherent after the intervention ( p < 0.001) and 67% of patients with initial LDL-hypercholesterolemia normalized their LDL level within two years ( p < 0.001). CONCLUSION: The Orchestra program has provided a unique opportunity to assess and improve prevention and management of co-morbidities in HIV patients.

Hardware of the flight experiment "Quail-SK" transport incubator.

The transportation of quail eggs in various stages of incubation was used in an experiment at the orbital station MIR by the Slovak astronaut, Bella in February 1999. Device description, diagrams, and experimental results are presented in this paper.

[The effect of hypodynamia on striated muscles in Japanese quail]. / Vplyv hypodynamie na priecne-pruhovanú svalovinu japonských prepelíc.

The effect of hypodynamia during 9, 30, 60 and 90 days on the striated muscle m. gastrocnemius in Japanese quails was studied. We have found different developed dystrophic changes of mitochondria, myofibrils and sarcotubular system. Changes of the studied tissue caused by hypodynamia in the first two groups (9 and 30 days hypodynamy) are the reaction to stress and developing situation. Gradually Japanese quails have come up to the influence of the hypodynamia (60 days hypodynamia). In the last experimental group deposit changes were observed (90 days hypodynamia). In comparison with control group we have found perturbations considered as non-specific, short-term and reversible.

Diabetic foot: a frequently misdiagnosed pathology. A survey on 185 cases.

Authors refer to the increasing significance of complications of diabetes mellitus. The most important of them is the diabetic osteoarthropathy of the foot which is often misdiagnosed in general practice. Authors report on 185 cases of diabetic foot treated at their department. iii of them were males and 74 females. Total number of admissions was 258 which means that some patients were repeatedly admitted. In 77 cases amputation was performed. Authors preferred the Burgess technique for below-knee amputation. Minor operations (amputations of digits, resections of metatarsal bones, etc.) were done in 125 cases. Total number of operations was 202. Authors refer to the limited results of conservative treatment. The 2.1 percentage mortality rate was due to the selection of patients suitable for rehabilitation.

Characteristics of enterococci and staphylococci isolated from the crop and caecum of Japanese quails exposed to microgravity conditions.

Ten selected strains of enterococci and staphylococci were isolated from the crop and caecum of Japanese quails exposed to microgravity conditions. Isolates were allotted to the species Enterococcus gallinarum, Ent. avium, Ent. faecium, Staphylococcus gallinarum and Staph. aureus. Isolated strains were facultatively anaerobic, non-motile, Gram-positive cocci, occurring in pairs, short chains or irregular clusters. Isolates utilized most of the soluble sugars tested and produced bacteriocin-like substances. Enterococci and staphylococci were resistant to monensin (50 mg/l) and sensitive to tylosin and virginiamycin (10 mg/l).

[The effect of high gravity on embryonic development in birds]. / Vplyv zvýsenej gravitácie na embryonálny vývoj vtákov.

An experiment was conducted on Japanese quail and hen hatching eggs that had been incubated, and the embryos were subjected to hypergravitation of 10 G for 10 min on days 1 to 9 of embryonic development. Both the experimental group and the control contained each 20 hatching eggs every day of the experiment (360 eggs in total). A centrifuge of the diameter 1,300 mm was used to create overload (hypergravitation) at the speed of 118 rotations per min. Tab. I shows the layout of the experiment. Embryonic mortality in Japanese quail was investigated during incubation by egg candling on days 1 to 8 and 9 to 14 while suffocated embryos were investigated on days 15 to 17. As for chicks, embryonic mortality was determined by egg candling on days 1 to 8 and 9 to 18, suffocated embryos were determined on days 19 to 21. After incubation was terminated, hatchability in per cent of the fertilized eggs was determined. The results were processed in two stages of development: the first stage days 1 to 5, the second stage days 6 to 9. As can be seen in Fig. 1, hypergravitation did not influence the hatchability of quail eggs in the first stage. But this experimental treatment resulted in a steep fall of hatchability in the second stage of observation in comparison with the control group (the difference is significant P < 0.01). Fig. 2 shows hatchability.(ABSTRACT TRUNCATED AT 250 WORDS)

[Bone and joint tuberculosis in Hungary today]. / A csont-ízületi gümökór ma Magyarországon.

Authors introduce to the history of efforts against tuberculosis in Hungary. The effectiveness of this figh is shown by the decrease of morbidity rates. The decrease of morbidity rates was followed by the cutting down of the system of institutions devoted to the conquest of tuberculosis. Authors give account on the present epidemiological conditions and report on the four and a half years activity of their bone and joint surgery department in this field. The department proved to be reliably suitable for the treatment of patients with bone and joint tuberculosis. They draw the attention to the significance of yearly 30 cases which show that the tuberculosis did not yet disappear from Hungary. The aim of the paper is to maintain the problem in the common medical consciousness.

[CT-guided percutaneous drainage in the management of psoas abscesses]. / Psoas tályogok kezelése CT vezérelt percutan drénezéssel.

The authors review their first experiences in Hungary with the CT guided percutaneous catheter treatment of psoas abscesses. Diagnostic aspiration from abscess was performed in one patient. Percutaneous catheter drainage of psoas abscess were performed in 4 patients. There were 4 patients with unilateral and 1 patient with bilateral psoas abscess. 4 patients had tuberculous spondylodiscitis, 1 patient had staphylococcal vertebral osteomyelitis. One patient following diagnostic aspiration was successfully treated with antituberculoutic drugs. All patient treated with percutaneous catheter drainage received medical antituberculoutic or antibiotic therapy and showed excellent clinical and radiological results. There was no complication and there was no need to open surgical drainage in this series. CT guided aspiration is a valuable tool in the diagnosis of psoas abscesses as well as in the identification of the exact abscess etiology. Percutaneous drainage represents an efficient and attractive alternative to open surgical drainage in the treatment of psoas abscesses.

[Experience in the management of osteomyelitis of the fibula]. / Tapasztalataink a fibula osteomyelitis kezelésével.

Authors report on experiences gained with the treatment of 22 cases of osteomyelitis of the fibula in the 17 years material of their Department. It is stated that the fibula osteomyelitis has to be treated first of all with operation and the end results of the treatment are good. In this, the anatomical situation which enables the resection and removal of the proximal part of this bone without more ado has a role. The more frequent occurrence of the disease on the right fibula in their material is an accidental finding.

[Quantitative ultrastructure of the myocardium of Japanese quail after long-term hypodynamia]. / Kvantitatívna ultrastruktúra myokardu japonskej prepelice pocas dlhodobej hypodynamie.

Quantitative ultrastructural myocardial changes of myocardium of the japanese quail (Coturnix coturnix japonica) were studied during an immobilization stress (hypodynamia) lasting 9, 30, 60 and 90 days. Hypodynamic quails were fixed by waistcoats to the feeding place simulating conditions of long lasting space flight which the quails were determined for. The surveyed morphological parametres were: mitochondrial rate, mitochondrial volume in % of cytoplasm, volume of myofibres in % of cytoplasm, volume of single mitochondria, extent of cristolysis. Progressive mitochondrial hydratation and even local oedema were observed during the experiment. It led to a progressive increase of mitochondrial volume and simultaneous decrease of volume of myofilaments as a sign of intracellular atrophy of myofibres. The results correlated well with a decreased mass of myofibres observed in experimental quails from space flight on the orbital station MIR.

Activity of ornithine decarboxylase in muscle of Japanese quail in hypergravity conditions.

Ornithine decarboxylase (ODC) is the rate limiting enzyme in the synthesis of polyamines which are generally required for animal cell proliferation. Because of many different stimuli changing the activity of ODC, the effect of hypergravity on muscle ODC activity in Japanese quail was investigated. Adult Japanese quail cockerels were exposed to 2G in the centrifuge permanently for 96 hours. The activity of ODC was determined by radioisotopic method in supernatant of homogenised breast and fibular muscles (m. pectoralis minor, m.superficialis fibularis). The activity of ODC was higher in breast muscle than in the fibular muscle in both, control and experimental groups. Exposition of quail to hypergravity evokes approximately 2 fold increase of ODC activity in both breast and fibular muscles. The results suggest that 96 hours of permanent hypergravitation (2G) caused activation of polyamine synthesis and their involvement in biochemical processes of adaptation to hypergravity.

Behaviour of newly hatched and adult Japanese quail and the feasibility of adaptation to weightlessness.

The aim of cosmic biology is to create conditions necessary for the long-term stay of man on cosmic orbital complexes and planetary stations. Such conditions should be provided by the autonomous closed ecosystem--a simplified model of the terrestrial biocenosis. As an experimental model of the higher heterotrophic link of this ecosystem the Japanese quail was chosen. This paper presents recent knowledge on the behaviour of newly hatched and adult quails under conditions of weightlessness. Videorecords made as part of the experiments aboard the MIR orbital station do not meet the criteria of systematic behavioural observation required for qualitative and quantitative behavioural analysis on earth. Nevertheless, the data is highly interesting and original, and was therefore analysed and summarized.

[First experience in Hungary with the use of a garamycin sponge in the treatment of suppurative bone and joint wounds]. / Elsö hazai tapasztalatok a garamycin-szivacs alkalmazásával csont ízületi gennyedések kezelésében.

Authors have implanted Garamycin sponge in 51 patients, suffering from suppuration of bones and joints. This is a sponge-like collagene material prepared from cattle tendon and containing Gentamycin. Their experiences have shown that this product is especially suitable for the treatment of infected cavities of minor tubular bones, whereas it is less suitable for the treatment of extensive cavities of long tubular bones. Attention is called to the fact, that the product had to be tried on "contraselected" material and they had only 5 exceptional cases in which it could be used as a "first therapeutic measure". Under such conditions the early, 50 per cent good results can be considered as promising. Authors close their paper with the description of 4 cases.

[Gentamycin concentration in the milk of a mother after treatment by implantation of a Septopal chain]. / Septopal-lánc beültetéssel kezelt anya tejének gentamicin tartalma.

The author implanted 90 beads of Septopal into the osteomyelitic femur of a wet mother. The excretion of gentamycin in the mother's milk was continuously examined. The investigations revealed that the excretion of gentamycin with the mother's milk was so minimal that it did not signify any risk for the newborn baby.

Modifications of the electrical activity in the ventromedial hypothalamic nucleus and the lateral hypothalamic area of 24-hour food-deprived rats.

The amplitude of the electrical activity of the ventromedial hypothalamic nucleus (VMH) and lateral hypothalamic area (LH) was evaluated in rats after 24-hr food deprivation to determine the effects of the diet they had received before fasting. Bioelectrical potentials were registered by means of monopolar electrodes. In rats after 24-hr food deprivation an increase in the absolute values of the amplitude of the electrical activity of the VMH and LH was found; this effect was more pronounced in the LH. Comparing the amplitude of the electrical activity of the VMH and LH, we found it to be always higher in the VMH in ad libitum fed rats, while in 24-hr food-deprived rats the electrical activity was always higher in the LH. The extent of changes depended on the diet the rats had received before fasting--they were most marked in rats fed on a high-protein diet and less marked in rats fed on either a standard or a high-fat diet before food deprivation.

[Conservative treatment of suppurative hematogenic arthritis of the hip joint]. / A gennyes haematogen csípöízületi gyulladás konzervatív kezeléséröl.

Authors collected from the 82 suppurations of the hip, during the 12 years activity of their Department, the cases treated from some reason conservatively. They had 21 such cases, 17 of them males. The average age of the patients was 38 years and the haematogenous way of the infection could be proven in 15 cases. The scheme of the treatment: very long.lasting giving of broad spectra antibiotics, temporary immobilization with extension, long-lasting relief of weight bearing, if necessary hip spica. The results are assessed critically. In this the tendency of recurrence of the disease, and that the longest follow-up was 10 years, in average however only 3.6 years, play a role. At closing of the material 12 patients stated to be free of complaints, the hip movements were completely retained in 4.9 cases are demonstrated in details and the "strategic" questions of the conservative treatment of the suppurations of the hip are discussed.