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.

Dual mode of extraction for Cs+ and Na+ ions with dicyclohexano-18-crown-6 and bis(2-propyloxy)calix[4]crown-6 in ionic liquids: density functional theoretical investigation

Experimentally observed distribution constant and theoretically predicted values of ΔG_ext for Cs⁺ and Na⁺ ions with DCH18C6 and BPC6 ligand in ionic liquid and octanol.

[Rapidly developing bone destruction in a patient with type 1 Gaucher disease]

The authors report on a 25 year-old male Gaucher patient who developed rapid bone deterioration. The patient was splenectomised at age 3 and had no signs and symptoms of bone involvement for more than 20 years. In addition to the infarction in the right tibia, severe bone necrosis was detected in components of the left hip. This report suggests that bone deterioration may develop insidiously at any time in Gaucher patients, and that long-term and regular follow up is warranted.

[Bone and joint tuberculosis in Hungary today]

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]

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.

[Gentamycin concentration in the milk of a mother after treatment by implantation of a Septopal chain]

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.

Antibiotic irrigation-perfusion treatment for chronic osteomyelitis

This paper reports 125 antibiotic irrigation-perfusion treatments of chronic osteomyelitic patients. The localisation of the osteomyelitic process, the duration of the disease, the duration of the treatment, the age distributions of the patients, and the results of the treatment are noted. The study revealed that only one third of the patients healed after the irrigation-perfusion treatment. This rate falls short of the results reported in the literature. The possible causes are discussed and emphasis is given to the technical problems. On the basis of this survey the author is of the opinion that this method is to be employed only in exceptional cases of bone infections. The indication and contraindications are precisely defined.

[Examination of antibiotic sensitivity/resistancy relations of strains of staphylococcus aureus haemolyticus originating from osteomyelitic patients (author's transl)]

On the basis of bacteriology results of osteomyelitic patients of the recent 10 year period the authors examined the changes of antibiotic sensitivity/resistancy relations of strains of coagulase positive Staphylococcus aureus haemolyticus. Examination of 385 strains of Staphylococci showed that Staphylococci originating from osteomyelitic patients are more sensitive, respectively in a lesser degree resistant to antibiotics than those of miscellaneous origin. Concerning 8, in everyday practice most commonly used antibiotics, by means of regression trend line analysis, it has been stated that in the period of 1966-1975 years Staphylococci originating from osteomyelitic patients show a decreasing resistancy to antibiotics examined. The authors are of the opinion that in osteomyelitic patients the no satisfactory results and the high number of recurrent inflammations are not attributable to resistant strains of Staphylococci, but are due to many other biologic factors.

[Hydraulic problems in so-called antibacterial suction-drainage of surgical infections and osteomyelitic cavities (author's transl)]

1. Suction-drainage should only be employed when there is a closed space enabling free flow of the irrigation fluid. 2. The drainage of the irrigation fluid must be ensured. 3. Positioning of the perforated drain is more important than the actual length of the perforated segment of the drain. Enlargment of the holes in the drain may prevent it from clogging and not so much an increase in the number of holes. 4. The irrigation system must be simple and not be complicated by Y-tubes. 5. Wound closure should be water-tight for the construction of a closed drainage system.