Examination of metal sorting and concentration technology in landfill mining -with focus on gravity and magnetic force sorting

The study focuses on the recovery of the minor metals contained in waste landfills. We have previously reported on the method of investigating the existing chemical morphology of each element in landfills, creating a high-concentration zone for a specific element, and non-destructively exploring the position of that within the block. In this study, a method for concentrating useful metals from landfills was examined, using samples taken from a concentrated zone. Specifically, the efficiency of physical sorting using gravity and a magnetic force was examined with samples collected from landfills mainly composed of incinerator ash. In the gravity sorting method, the resulting metal concentration is large when the heavy liquid specific gravity is 2.5 or 2.75 g/cm3 and above. Currently, sorting using a heavy liquid with a specific gravity of 2.75-3.0 g/cm3 is effective for increasing the metal concentration of the sample. Magnetic force sorting can efficiently separate metals and non-metals, and is effective as a pretreatment for a more advanced concentration stage. Various substances are mixed within the landfill waste, and several stages of sorting and concentration treatments are required to extract useful minor metals. A physical sorting method, such as the use of gravity or magnetic force is effective for the initial stage processing. Furthermore, when the metal to be extracted has been determined, a more effective concentration method based on the chemical form and characteristics of the target metal will be further examined for these pretreated samples.

Two-step extraction method for lead isotope fractionation to reveal anthropogenic lead pollution

This study developed the 2-step extraction method which eluted the Pb adsorbing on the surface of sediments in the first solution by aqua regia and extracted the Pb absorbed inside particles into the second solution by mixed acid of nitric acid, hydrofluoric acid and hydrogen peroxide solution. We applied the method to sediments in the enclosed water area and found out that the isotope ratios of Pb in the second solution represented those of natural origin. This advantage of the method makes it possible to distinguish the Pb between natural origin and anthropogenic source on the basis of the isotope ratios. The results showed that the method was useful to discuss the Pb sources and that anthropogenic Pb in the sediment samples analysed was mainly derived from China because of transboundary air pollution.

Estimation of the potential of landfill mining and exploration of metal-enriched zones

Since the Industrial Revolution, people have exploited natural resources to manufacture products. Many of the products have later been disposed of in landfills and the like. The aim of this study was to determine the contents and chemical forms of valuable rare metals in landfills and to identify the metal-enriched zones in landfills using non-destructive prospecting methods. Box experiments were performed using four mixtures of sand and iron sulfide particles, and excavated waste samples. Field prospecting studies were performed at an industrial landfill site. As a result, it is possible to establish a grading system for elements based on the maximum contents in the fill, and the condition in the fill is found to potentially affect the metal distribution. In addition, investigations for rare metals coexisting with iron sulfide were performed at each target site. This allowed zones with high rare metal contents in the fill to be identified in a non-destructive manner. Based on the above approach, a basic evaluation of a landfill site that could be used as an "urban mine" was accomplished.

Genetic identification of two distinct DNA polymerases, DnaE and PolC, that are essential for chromosomal DNA replication in Staphylococcus aureus

We isolated and characterized temperature-sensitive mutants for two genes, dnaE and polC, that are essential for DNA replication in Staphylococcus aureus. DNA replication in these mutants had a slow-stop phenotype when the temperature was shifted to a non-permissive level. The dnaE gene encodes a homolog of the alpha-subunit of the DNA polymerase III holoenzyme, the replicase essential for chromosomal DNA replication in Escherichia coli. The polC gene encodes PolC, another catalytic subunit of DNA polymerase, which is specifically found in gram-positive bacteria. The wild-type dnaE or polC gene complemented the temperature-sensitive phenotypes of cell growth and DNA replication in the corresponding mutant. Single mutations resulting in amino-acid exchanges were identified in the dnaE and polC genes of the temperature-sensitive mutants. The results indicate that these genes encode two distinct DNA polymerases which are both essential for chromosomal DNA replication in S. aureus. The number of viable mutant cells decreased at non-permissive temperature, suggesting that inactivation of DnaE and PolC has a bactericidal effect and that these enzymes are potential targets of antibiotics.

Long-term outcomes of immunosuppressed renal transplant recipients with malignancies

This study analyzes ten cases of malignancy in a cohort of 183 renal transplant recipients, examining surgical management, postoperative immunosuppressive therapy, and long-term outcome. One of these ten patients, who had malignant lymphoma of the jejunum, died of the neoplasm, but the other nine patients did not show any signs of tumor recurrence after removal. All of these nine patients, except for one who had transplant renal cell carcinoma (RCC), received the same dose of immunosuppressive agents after surgery for the malignant disease. Seven patients were still alive at the time of this report, six of whom had good transplant renal function. The findings of this study indicate that even if immunosuppressive agents predispose to the development of cancer, it is not necessary to reduce their dose after removal of the tumor.

[Tumor reduction in advanced renal cell carcinoma with tumor thrombus by renal embolization, interferon-alpha and UFT. A case report]

A 73-year-old man with renal cell carcinoma involving the left renal vein was treated with the embolization of the left renal artery followed by interferon-alpha and UFT. Computerized tomography revealed 53% reduction of the primary lesion and 47% reduction of the tumor thrombus 40 days after treatment. The histopathological study revealed marked lymphocyte infiltration and necrosis of the tumor after nephrectomy.

[Magnetic resonance imaging (MRI) of bone marrow necrosis]

Magnetic resonance (MR) of bone marrow was studied in two cases of acute leukemia which showed bone marrow necrosis. Case 1:A 24-year-old female was admitted because of sternum pain and bleeding tendency. She was diagnosed AML based on the peripheral blood picture. Bone marrow biopsy revealed the presence of bone marrow necrosis. T1 weighted imaging of MR showed low signal intensity in all vertebral marrow. Fatty marrow was demonstrated after achieving complete remission and the MR imaging of bone marrow changed to show high intensity, suggesting fat deposition. Case 2: A 19-year-old female suffered from chest pain and lumbago, and was diagnosed as ALL. DIC and bone marrow necrosis were confirmed during chemotherapy for remission induction. T1 weighted imaging showed the mosaic pattern of low and high signal intensity. She achieved complete remission and bone marrow clot revealed the presence of fatty marrow. Most areas of low signal intensity of T1 weighted imaging changed to those of high signal intensity. These observations suggest that necrotized bone marrow seemed to change to fatty marrow along with achieving remission. MR imaging study of bone marrow is useful for evaluating hematopoiesis in hematologic disorders.

Somatic Embryogenesis and Clonal Multiplication of Panax ginseng

Embryogenesis of PANAX GINSENG was induced from young flower buds via callus during a 3 months culture period. Matured embryos could be germinated on the 1/2 Murashige and Skoog's medium supplemented with GA (3) (1.4 microM)-BAP (2.2 microM) and 1.5% sucrose. In the medium containing 1.4 microM GA (3) and 11.1 microM BAP, a multiple shoot complex having 8 shoots per segment was formed from a single shoot set. On the other hand, the addition of 11.1 microM BAP and 1.4 microM GA (3) to the medium stimulated the flower bud formation. For root formation of shoots, the MS medium supplemented with 5.4 microM NAA was the most favourable. Subsequently the plantlet was transferred to vermiculite.

Clonal Multiplication of Aconitum carmichaeli by Tip Tissue Culture and Alkaloid Contents of Clonally Propagated Plant

Shoot tips and axillary buds of ACONITUM CARMICHAELI Debx. cultured in Murashige and Skoog medium supplemented with 5 ppm BAP at 25 +/- 1 degrees C under continuous light for 6 weeks formed multiple shoots with an average of 7 shoots per culture. Multiple shoot forming ability does not decrease at least for 6 generations. Subsequent culture of these shoots on MS medium supplemented with 0.5 ppm IAA at 20 +/- 1 degrees C under continuous light for 6 weeks resulted in root formation. The plantlets were transplanted successfully in the soil. Alkaloid contents of clonally-propagated plants showed less variation than those of the normally grown plants.

[A comparative study of the effects of drug therapy and bladder training therapy]

Treatment of enuresis was studied in 168 patients. The patients were divided into two groups, the drug therapy group which consisted of 88 patients who were treated with drugs only, and the bladder training therapy group which consisted of 80 patients who were treated mainly with bladder training supplemented with drug therapy. In the drug therapy group imipramine was the first choice and was used at bed time. The dose of imipramine was initially 1 mg/kg and was gradually decreased if it worked well, and changed to other drugs if it did not work well. In the bladder training therapy group, bladder training was performed in all patients for 3 months, and 22 patients who cured further bladder training was continued, whereas the rest of the patients (58 patients) drug therapy was started in addition to bladder training. After 3 months, drug therapy was effective for 54 patients (61%) including 10 patients (11%) who were cured, and bladder training therapy plus drug therapy was effective for 55 patients (69%) including 22 patients (28%) who were cured. The number of cured patients in the bladder training therapy group was significantly larger than that of the drug therapy group (p less than 0.01). After 6 months, drug therapy was effective for 56 patients (64%) including 16 patients (18%) who were cured, and bladder training therapy plus drug therapy was effective for 66 patients (83%) including 30 patients (38%) who were cured. The number of effective and cured patients in the bladder training therapy group was significantly larger than that in the drug therapy group (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)