Gasification of polyethylene using steam plasma generated by microwave discharge

Gasification of polyethylene (PE) pellet was studied using atmospheric argon-steam plasma generated by microwave discharge and the feasibility of the process was examined. The experimental results showed that additional steam to argon plasma promoted the weight decrease of PE and enhanced the production of H₂, CO, CO₂ and CH₄. The results confirmed that the treatment of plastics with the steam plasma was effective to obtain synthesis gas.     

Cyclin D1 overexpression in malignant lymphomas

Cyclin D1, the regulatory subunit of certain protein kinases thought to advance the G1 phase of the cell cycle, is now established as a proto-oncogene, with evidence indicating that its derangement may contribute to the uncontrolled cell growth characteristic of tumors. The chromosomal translocation t(11;14)(q13:q32), involving rearrangement of the BCL-1 locus, is closely associated with human lymphoid neoplasia affecting mantle cell lymphomas (MCL). Recently, the putative BCL-1 proto-oncogene turned out to be none other than the cyclin D1 gene. Although the observed break points in the BCL-1 locus are not tightly clustered, its rearrangement has been documented in 40-70% of cases of mantle cell lymphoma, whereas it only rarely occurs in other B cell lymphomas. Of note, all of the known break points leave the cyclin D1 coding region structurally intact and result in increased protein expression, implying that this may provide a highly sensitive and specific marker for MCL. Recent studies demonstrated that immunohistochemical detection in paraffin-embedded material, using a monoclonal antibody, is very useful for routine diagnosis. Current knowledge of cyclin D1 overexpression in malignant lymphomas, with emphasis on its clinicopathologic significance, is reviewed.     

Treatment approaches following foot and ankle injury

A complete and effective rehabilitation program begins with a thorough subjective and objective evaluation of the problem and injury presented. Biomechanical changes, whether they are anatomically induced or as a result of a form of compensation, must be identified and properly addressed. During the initial phase of rehabilitation, the issues of pain and swelling often must be resolved before full range of motion and return to normal strength can be achieved successfully during the more advanced stages. It is important to incorporate the entire lower quadrant in exercises that are designed to improve proprioception and function, using both in open and closed kinetic chain exercises. Finally, the demands to which the patient is returning to must be recognized to successfully complete the recovery phase.     

Small increase of CR1 and CR3 by C5a-receptors on polymorphonuclear leukocytes in systemic lupus erythematosus

One of the anaphylatoxins, C5a, is known to increase the expression of the complement receptors, CR1 and CR3, on PMNs which play important roles in the phagocytosis. We measured the expression of these receptors before and after the stimulation with C5a and C5a-receptors (C5aR) on PMNs in patients with systemic lupus erythematosus (SLE). PMNs from 16 patients and 11 normal controls were tested. All the patients with SLE were administered with prednisolone orally and were in the inactive stage. The CR1 expression in SLE was significantly weak (p < 0.01) before and after stimulation with 4.55 nM (50 micrograms/ml) of C5a. There was no significant difference of CR3 expression before stimulation. However, after the stimulation with C5a, the increase of CR3 on PMNs from SLE was significantly small (p < 0.01). C5aR on PMNs showed no difference between the two groups. However, the expression of C5aR was significantly suppressed in patients treated with a high dosage of prednisolone (> = 10 mg/day) compared to those with a low dosage of prednisolone (< 10 mg/day). There was no significant difference of CR1 and CR3 expression between these groups. It is concluded that the increase of CR1 and CR3 on PMNs by C5a in small in SLE, of which impaired increase is not due to C5aR on PMNs, and that the expression of C5aR is suppressed by prednisolone.     

Endoscopic treatment of vesicoureteral reflux in patients with myelodysplasia

PURPOSE: We assessed the usefulness of and indications for endoscopic treatment of vesicoureteral reflux in myelodysplasia patients. MATERIALS AND METHODS: A total of 26 patients treated with intermittent catheterization was divided into 11 (16 ureters) with and 15 without vesicoureteral reflux. In 9 patients (13 ureters) endoscopic correction was performed with 3% atelo-collagen and without anesthesia at the outpatient clinic. In each ureter we obtained the sum of scores for 4 risk factors for upper urinary tract deterioration: bladder compliance less than 10 ml./cm. water, grade 2 to 3 bladder deformity, detrusor-sphincter dyssynergia and urethral closure pressure 50 cm. water or greater. RESULTS: No reflux was demonstrated immediately after the initial collagen injection but cystography 3 to 6 months later showed recurrent reflux in 5 ureters (38%). Repeat injection cured the reflux, with results persisting for an average of 17 months. Mean risk factor score for patients without vesicoureteral reflux was significantly lower than that for patients with reflux. In patients treated with intermittent catheterization and anticholinergic agents the mean score for ureters with an increased or unchanged reflux grade was significantly greater than for those with a decreased grade. CONCLUSIONS: Endoscopic treatment of reflux appears to be safe and useful in patients with myelodysplasia. The treatment is preferable in those with high risk factor scores due to the possibility of increased reflux grade in such patients.     

Experience with the antibiotic resistance analysis and DNA fingerprinting in tracking faecal pollution at two lake beaches.

Posting or closing of swimming beaches because of faecal contamination is a widespread problem reported in many locations. In a risk-based approach to this problem, the risk to swimmers' health is assessed by field monitoring of indicator bacteria and the associated risks are managed by source controls and other remedial measures. In risk assessment, great advances have been made in recent years with the introduction of microbial source tracking (MST) techniques. Two such techniques, antibiotic resistance analysis and DNA fingerprinting, were applied in a study of causes of faecal contamination at two lake beaches in Toronto, Ontario. Both methods identified bird faeces as the dominant sources of E. coli. Coping with this type of pollution presents a major environmental challenge.     

Electrochromic properties of alkylviologen-cyclodextrin systems

Electrochromic properties of methyl, ethyl, n-hexyl and n-heptyl viologens, and -, -, -cyclodextrin systems were studied using cyclic voltammetry and absorption spectroscopy. Colourations of red-violet ( _max = 530 or 560 nm), blue ( _max = 600nm) and light purple ( _max = 560 and 600 nm) could be obtained by changing the length of the alkyl chain of viologens or the radius of cyclodextrin. The intermolecular interaction between viologen radicals is weakened when the radicals form inclusion complexes so the blue colour inherent in the monomer of viologen radical appears. The red-violet colour is ascribed to the dimer of the reduced viologen. With the addition of -cyclodextrin, viologens were found to be included as dimer. The light purple colour is ascribed to the mixed colour of the monomer and the dimer. Furthermore, since the ratio of monomer and dimer depends upon the concentration of cyclodextrin, any colour between the red-violet of the dimer and the blue of the monomer can be obtained by adjusting the concentration of cyclodextrin. The redox reaction of an inclusion complex was found to depend upon the length of the alkyl viologen and the size of the cavity in cyclodextrin.     

Kinetic study on the first stage during thermal degradation of polystyrene

The kinetic parameters of the first stage of polystyrene degradation have been investigated to elucidate the reaction mechanisms using the flow reactor system. The decrease in molecular weight of polystyrene was recorded at minute intervals over the temperature range 310°–390°C. Generally, the first and second stages were observed by thermogravimetric analysis (t.g.a.), however in the early stage of the degradation volatile yields of at least 5% occurred. Therefore, using t.g.a. analysis it is difficult to detect this earlier stage. It became evident that the first stage in the earlier part of the reaction could be detected by g.p.c. analysis. We have observed the hidden kinetic parameters of the nature of the first stage of the polystyrene degradation. The results indicate that the main chains were degraded randomly with the small quantitative volatile groups in the first stage and the rates of decrease in molecular weight in the first stage against reaction temperatures were evaluated as log k_s = 12.0 ? 41300/RT.     

Local structure and concentration in Al-Mn alloy electrodeposits

The structures of f.c.c. crystalline and amorphous phases coexisting in Al-Mn alloy electrodeposits containing 11–30 wt% were examined by using the grazing-incidence X-ray diffraction (GIXD) method, high-resolution transmission electron microscopy combined with energy dispersive X-ray spectrometry (HRTEM/EDS), and the manganese K-edge extended X-ray absorption fine-structure (EXAFS) technique. The amorphous and f.c.c. phases were homogeneously distributed in the through-thickness direction of the electrodeposits, although the amorphous phase increased and the f.c.c. phase decreased with increasing manganese total concentration. The decrease of Mn-content in the f.c.c. crystalline phases with increasing manganese total concentration was revealed by the lattice constant measurement of the f.c.c. crystalline phase. This result was also supported by the microarea elemental analysis by HRTEM/EDS. The EXAFS result has indicated that the manganese local structures in the amorphous phases are almost identical in different manganese total concentration electrodeposits. This suggests that the Mn-content in the amorphous phases hardly changes with increasing manganese total concentration. These results have revealed that a peculiar elemental partition occurs in the amorphous and crystalline phases of Al-Mn alloy electrodeposits.     

Melt viscosity and flow birefringence of polycarbonate

Melt viscosity and flow birefringence of bisphenol A-type polycarbonate were measured and analyzed by the application of rubber-like photoelastic theory. The melt viscosity in the Newtonian flow region increased with the molecular weight to the power of 3.4. In polycarbonate, the shear stress of the Newtonian flow region was to 10⁶ dyn/cm², whereas in PMMA it was at most 3 = 10⁵ dyn/cm². The flow birefringence δn has a linear relation with shear stress S, that is δn = 5.7 × 10^?10 S. The principal polarization difference of flow unit α₁ – α₂ was 1.62 × 10^?23 cm³, which was obtained by the application of the rubber-like elastic theory. In PMMA, it was 3.9 = 10^?25 cm³; about 1/40 of that was polycarbonate. The anisotropy of polarizability of the flow unit of polycarbonate was also about 40 times larger than that of PMMA. So the anisotropy reflected the large flow birefringence of the polycarbonate.