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  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 1018-1022 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A simple model is presented for the complex dielectric function, ε(E)=ε1(E)+iε2(E), of CdxZn1−xSe alloy. The effects of alloy composition are properly taken into consideration in the calculation. The model is applicable over the entire range of photon energies, below and above the lowest band gap, and is in relatively good agreement with the existing experimental data. Dielectric-function-related optical constants, such as the real refractive index (n), extinction coefficient (k), and high-frequency dielectric constant (ε∞), of this alloy system have also been presented. The present results can be used in the design and analysis of various optoelectronic devices using this alloy system. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 82 (1997), S. 1320-1326 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Thermoreflectance (TR) spectra of Te-based II–VI compounds ZnTe and CdTe are presented. Measurements are carried out on the bulk single crystals in the 2.0–5.6 eV photon-energy range at room temperature. The TR spectra obtained reveal distinct structures at energies of the E0, E0+Δ0, E1, E1+Δ1, E0′, and E2 critical points (CPs). Detailed analyses are made using a simplified model of the interband transitions. Results suggest that the E0 and E0+Δ0 structures can be characterized by a three-dimensional M0 CP, the E1 and E1+Δ1 structures by a two-dimensional (2D) M0 CP, and the E0′ and E2 structures by a damped harmonic oscillator (a broadened 2D M1 CP). It is also concluded that the broadening terms cannot be neglected in the analysis of TR spectra. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1442-2042
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background: Optimal therapy for stage I testicular tumors is still controversial. This study evaluated the efficacy of a surveillance policy for patients with testicular stage I seminomas and nonseminomatous germ cell tumors (NSGCT). Methods: From 1984 to 1996, 24 patients with stage I semi noma and 20 with stage I NSGCT were fol lowed after radical orchiectomy with tumor markers and imaging studies. All patients were followed for at least 2 years except for those who recurred within 2 years. Recurrent patients were treated with cisplatin-based chemotherapy. Results: The median follow-up periods for seminoma and NSGCT patients were 41 and 54 months, respectively. Recurrences were detected in 2 seminoma (8.3%) and 10 NSGCT (50%) patients. Eleven of the 1 2 recurrent patients (92%) were detected within 2 years after orchiectomy. The seminoma patients both recurred in the retroperitoneal lymph nodes, while 70% of the NSGCT patients recurred in the lung and/or retroperitoneal lymph nodes. The recurrent seminoma patients were treated with chemotherapy and are alive without disease for 1 7 and 24 months after orchiectomy. One NSGCT patient died of cancer, but the other 9 recurrent NSGCT patients are alive without disease at 25 to 11 3 months after orchiectomy. Conclusions: Surveillance alone is reliable for monitoring patients with stage I testicular seminoma and NSGCT. The majority of recurrences occurred within 2 years, necessitating intensive follow-up for 3 years. As the lung metastatic rates in NSGCT patients were high, a more accurate assessment for lung metastasis is desirable in these patients.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1442-2042
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background : Simultaneous determinations of human chorionic gonadotropin hormone (hCG) and hCG-β frequently produce discrepancies, that is when hCG or hCG-β is normal, the other is elevated. Accordingly, we examined the significance of simultaneous determination of serum hCG and hCG-β in testicular tumors. Methods : Simultaneous determination of hCG and hCG-β was performed in 54 patients with testicular seminoma and 74 with non-seminomatous testicular tumors. Results : For detection of seminoma patients, hCG-β was more effective than hCG because hCG-β was positive in 83% (45/54) of the patients and hCG was positive in 50% (27/54). In non-seminomatous testicular tumor cases, hCG-β was positive in 74% (55/74) and hCG was positive in 82% (61/74). The cases of hCG 〈1.0 mIU/mL and HCG-β 〉 0.1 ng/mL were significantly more frequently seen in patients with seminoma than in those with non-seminomatous testicular tumor (P 〈 0.001). Fourteen patients had recurrent tumor. At recurrence, only hCG was elevated in nine cases, only hCG-β was elevated in two cases and both in one case. For diagnosis of falsely positive hCG, testosterone administration was effective because after testosterone administration, serum hCG levels became undetectable (〈 1.0 mIU/mL) within one week in three examined cases. Conclusion : Human chorionic gonadotropin-β was a better marker of seminoma than hCG. For earlier detection of recurrence, both markers should be examined. For diagnosis of falsely positive hCG, testosterone administration was effective.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1442-2042
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background: After chemotherapy for metastatic testicular tumors, masses may remain, often in the metastatic sites. This study analyses the role of resections for the residual masses. Methods: Seventy-seven patients with advanced (stage II, III) testicular tumors were treated. Of these, 38 patients, including eight with seminoma and 30 patients with non-seminomatous germ cell tumors, underwent resection of residual masses after chemotherapy and have been followed for a median of 41.5 months (range 2–138) after the resection. Results: Residual masses were necrosis/fibrosis in 19 patients, mature teratoma in 11 and cancer in eight. The ratio of cancer in stage III (41.2%) was significantly higher than that in stage II (4.8%). Ten of 38 (26.3%) patients experienced recurrences in sites other than the resected sites, and five of 10 patients have died of cancer. Most recurrences (80%) occurred within two years. Recurrences after resection were detected in 4.8% of stage II patients, 52.9% of stage III, 16.7% of necrosis/fibrosis and mature teratoma, and 62.5% of cancer. The survival rate of patients with cancer was significantly lower in spite of adjuvant chemotherapy after surgery. Conclusions: Resection for residual masses after chemotherapy in metastatic testicular tumors was useful in confirming the tissue and in controlling the metastatic sites. Recurrences were often found in patients with cancer in the residual mass and the prognosis of patients with cancer was poor, therefore the development of more effective therapy for patients with cancer is required to improve the prognosis.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Melbourne, Australia : Blackwell Science Pty
    International journal of urology 6 (1999), S. 0 
    ISSN: 1442-2042
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract Purpose : Reverse transcriptase–polymerase chain reaction (RT–PCR) offers a potentially more sensitive assay for detecting cells expressing prostate-specific antigen (PSA) mRNA in peripheral circulation. But the sensitivity and specificity are variable depending on the position of the PSA amplification. To increase sensitivity and specificity, the whole PSA cDNA (1466 bp) was separated into eight different parts. Methods : We examined RT–PCR on 12 urogenital cell lines, including three prostate cancer (LNCaP, PC3, DU145), five human renal cell carcinoma (SMKT-R3, TOS-1, TOS-2, R4, ACHN), two urinary bladder cancer (YTS-1, KK-47) and two testicular cancer (NEC8, NEC14) cell lines. The sizes of the eight fragmented PSA used in the experiment were PSA-1 (1–257 bp), PSA-2 (1–322 bp), PSA-3 ( 172–507 bp), PSA-4 (172–851 bp), PSA-5 (595–1347 bp), PSA-6 (682 967 bp), PSA-7 (682–1347 bp) and PSA-8 (863–1466 bp). Results : All cell lines had positive signals from PSA-6, PSA-7 and PSA-8. The positive signals from PSA-1, PSA-2 and PSA-3 were detected in some other cell lines in addition to the three prostate cancer cell lines. Only LNCaP which produces the PSA protein had a positive signal from PSA-5. PC3 and DU145 (which do not produce PSA) and LNCaP had a positive signal from PSA-4. Therefore, the inner primer PSA-4′ (578–782 bp) used to increase sensitivity and specificity. Nested RT–PCR on the 12 cell lines, using the PSA-4 and 4′ primers, detected more clear bands in the three prostate cancer cells. Conclusion : Nested RT–PCR using PSA-4 (outer primer) and PSA-4′ (inner primer) may be useful for detecting prostate cancer cells in the peripheral blood.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1442-2042
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background: Neobladder, using the intestine, was performed after neoadjuvant therapy and total cystectomy as a treatment for invasive bladder cancer.Methods: Between January 1977 and April 1997, an ileocecal neobladder was used for 23 patients and a sigmoid neobladder was chosen for use in 32 patients. For the diagnosis of invasive bladder cancer and the evaluation of neoadjuvant therapy, we used whole-layer core biopsy (WLCB) of the bladder tumor and fine needle aspiration biopsy (FNAB) of pelvic lymph nodes after bipedal lymphography. For neoadjuvant therapy, two to four courses of internal iliac arterial infusion chemotherapy (IIA) were undertaken in 32 patients. Five patients were treated with IIA combined with 40 Gy irradiation to the pelvic space.Results: Pretreatment WLCB revealed a tumor of stage T2b or greater in 10 patients. After neoadjuvant therapy, three patients were down-staged to pT0. In five patients, pretreatment FNAB revealed pelvic lymph node metastases that were not detected by computed tomography or magnetic resonance imaging. Fine needle aspiration biopsy post-neoadjuvant therapy revealed tumor stage N0 in all patients and lymph node dissection revealed pN0 in four patients. Of the five patients who received 40 Gy irradiation, none had any postoperative complications, such as intestinal fistula or urinary leakage. Four male patients (10%) had urethral recurrence, but all were successfully treated by transurethral resection. Two patients treated prior to 1985 experienced local recurrence. Neither was treated by neoadjuvant therapy. Eight patients who died after 1985 had metastatic cancer, but none had local recurrence. None of the patients who received a sigmoid neobladder required clean intermittent catheterization or had bilateral vesico-ureteral reflux.Conclusions: Neoadjuvant therapy seems to reduce local recurrence in invasive bladder cancer. The sigmoid colon may be suitable for neobladder.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Annals of operations research 45 (1993), S. 187-204 
    ISSN: 1572-9338
    Schlagwort(e): Asymptotic growth rate ; asymptotic variance ; portfolio optimization ; mean-variance model
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik , Wirtschaftswissenschaften
    Notizen: Abstract This paper is concerned with a portfolio optimization model for a long planning horizon. We first argue that in this case the asymptotic growth rate and the asymptotic variance are better measures of performance than the usual mean and variance of return. We next propose an efficient algorithm for calculating the asymptotic frontier, i.e., the efficient frontier relative to the new criteria. Finally, we illustrate our methods and compare the difference between our model and the classical mean-variance-model by using historical data based on the 1064 stocks of the Tokyo Stock Exchange.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 411 (1987), S. 45-52 
    ISSN: 1432-2307
    Schlagwort(e): Diabetes ; BB rat ; Myocardium ; Loss of myofilament ; Contraction band
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The cardiac muscle of BB Wistar rats suffering from diabetes for 8 and 16 weeks (8-Wk and 16-Wk of DM) were examined by light and electron microscopy. The diabetic rats were kept alive by injections of small doses of insulin and exhibited severe hyperglycaemia, glycosuria and weight loss. The heart/body weight ratio of all diabetic groups was greater than that of age matched controls. Over the experimental period, the left ventricular myocardium of the diabetic BB rats sustained damage that was progressively more serious with the duration of the diabetic state. In BB rats after 8-wk of diabetes the myocardium contained large numbers of lipid droplets and glycogen granules around mitochondria which showed patchy swelling, and slight loss of myofilaments. Disruption of mitochondrial membranes and extensive loss of myofilaments were seen in rats diabetic for 16 wk. In addition, dilatation of the sarcoplasmic reticulum-transverse tubular system, formation of a contraction band and myelin bodies and widening of the intercellular space at the fasciae adherens of the intercalated disc were characteristically observed in BB rats after 16-wk of diabetes. However, there were no evident alterations in the capillaries of any diabetic BB rats. Morphometric analyses showed the volume percentage of myofibrils in diabetic rats to be significantly decreased when compared with controls. The loss of myofibrillar elements may be a primary damage induced by insulin deficiency. The formation of contraction bands suggests Ca2+ overload caused by diabetic metabolic disturbances.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1432-2307
    Schlagwort(e): Pigmented adenoma ; Cushing's syndrome ; Lipofuscin ; Ultrastructure ; Steroid analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ultrastructural and morphometrical analysis of brown pigment in pigmented (black) and non-pigmented adrenocortical adenomas of Cushing's syndrome and non-functioning pigmented adrenocortical nodules was performed in reference to tissue concentrations and in vitro production of steroids by the adenoma tissue. Pigment in pigmented adenomas was of membrane-bound lysosomal nature, while that of pigmented nodules contained membrane-unbound droplets of lipoid character. The morphometrical study showed little difference among individual adenomas. There was no difference between pigmented and non-pigmented adenomas in the amount of production and tissue concentrations of steroids. The steroid concentrations in a pigmented nodule were lower than those in an adenoma of Cushing's syndrome, but not significantly. Discussion is focused on the difference of pigment of lysosomal nature and of lipoid peroxidation.
    Materialart: Digitale Medien
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