Selection of metal oxide charge transport layers for colloidal quantum dot LEDs.

We investigate the effect of the electronic energy level positioning, conductivity, and morphology of metal oxide charge transport layers on the performance of light emitting devices (LEDs) that consist of a colloidally synthesized quantum dot (QD) luminescent film embedded between electron and hole injecting ceramic layers. We demonstrate that understanding of these material properties and their effect on charging processes in QDs enables the systematic design of higher efficiency QD-LEDs and excitation of QDs with different emission colors using the same device structure.

Vibrational spectroscopy reveals electrostatic and electrochemical doping in organic thin film transistors gated with a polymer electrolyte dielectric.

We apply attenuated total internal reflection Fourier transform infrared (ATR-FTIR) spectroscopy to directly probe active layers in organic thin film transistors (OTFTs). The OTFT studied uses the n-type organic semiconductor N-N'-dioctyl-3,4,9,10-perylene tetracarboxylic diimide (PTCDI-C8) and a polymer electrolyte gate dielectric made from poly(ethylene oxide) and LiClO4. FTIR spectroscopy of the device shows signatures of anionic PTCDI-C8 species and broad polaron bands when the organic semiconductor layer is doped under positive gate bias (VG). There are two distinctive doping regions: a reversible and electrostatic doping region for VG 2 V. On the basis of intensity loss of vibrational peaks attributed to neutral PTCDI-C8, we obtain a charge carrier density of 2.9 x 10(14)/cm2 at VG=2 V; this charge injection density corresponds to the conversion of slightly more than one monolayer of PTCDI-C8 molecules into anions. At higher gate bias voltage, electrochemical doping involving the intercalation of Li+ into the organic semiconductor film can convert all PTCDI-C8 molecules in a 30-nm film into anionic species. For comparison, when a conventional gate dielectric (polystyrene) is used, the maximum charge carrier density achievable at VG=200 V is approximately 4.5 x 10(13)/cm2, which corresponds to the conversion of 18% of a monolayer of PTCDI-C8 molecules into anions.

Anxiety, depression and quality of life of cancer patients undergoing radiation therapy: a cross-sectional study in a community hospital outpatient centre.

The purpose of the present study is to determine the impact of illness characteristics and psychopathological comorbidity on the quality of life (QoL) of radio-oncological patients in health-related and individual dimensions. Sixty-three of 93 eligible patients (40 women and 23 men) were included in the study during their radiation therapy visit to an outpatient centre annexed to a community hospital in Southern Bavaria, Germany. In a semi-structured interview, we elicited individually relevant life domains rated by the patients according to the 'Schedule for the Evaluation of Individual Quality of Life - Direct Weighting'. In addition, the participants completed the 'European Organization for Research and Treatment of Cancer (EORTC) QoL Questionnaire Core 30' and the 'Hospital Anxiety and Depression Scale'. We also assessed the demand for psychotherapy and utilization of psycho-oncological services. In total, 9.5% of the examined patients suffer from clinically relevant anxiety and/or depression [total Hospital Anxiety and Depression Scale (HADS) score >19]. There was a weak positive correlation between Karnofsky's Performance Status and QoL. Anxiety and depression were significantly correlated with impaired QoL, especially with impaired individual QoL. There was no association between psychopathological comorbidity and the requirement for psycho-oncological support. Conversely, patients who report difficulties in accepting help had a significantly lower QoL. Psychopathological comorbidity has a considerable influence on QoL of patients undergoing radiotherapy. Measuring the individual QoL appears as an adapted needs assessment and helps the psychotherapist in focusing on the patient's problems and desires. Furthermore, the patient's QoL is a main target in providing or planning mental health care in non-university oncological services.

Porphyrias associated with malignant tumors: results of treatment with ionizing irradiation.

BACKGROUND: Porphyrin metabolism disorders, known as porphyria, represent inherited or acquired diseases. The development of porphyria due to light sensibility occurs especially with exposure to wavelengths in the range of 300-700 nm. Skin reactions and neurovisceral dysfunctions are known side effects of ionizing irradiation. It can be postulated that during or after ionizing irradiation treatment of patients affected with tumor and porphyria, severe side effects might appear, in contrast to patients without porphyria. This paper describes the treatment of 2 patients affected with tumor and concomitant porphyria. PATIENTS: One female patient suffering from intermittent porphyria and breast cancer and one male patient suffering from porphyria cutanea tarda and bladder cancer were treated with ionizing irradiation (electrons and photons). No abnormalities nor any severe general or local side effects could be observed. CONCLUSION: Radiation therapy is not a 'stimulating' factor in activating porphyria symptoms.

Quantitative radioluminography of (125)Iodine whole-body autoradiograms.

Radioluminography (RLG) was applied for the quantitation of (125)iodine ((125)I) autoradiograms using the bioimaging analyzer BAS 2000. RLG was performed on 50-microm sections of sagittal whole-body sections of rats and (125)I-radiolabeled erythrocyte calibration scales. Linearity, sensitivity, accuracy, and reproducibility were investigated in comparison to direct (125)I radioactivity measurement. RLG is demonstrated to be a simple, reproducible, and precise analytical tool. However, the spatial resolution of quantitative (125)I RLG is limited by the relatively high average free path of gamma-radiation and X rays.

[The prognostic factors following the simultaneous radiochemotherapy of anal canal carcinoma in a multicenter series of 139 patients]. / Prognostische Faktoren nach simultaner Radiochemotherapie des Analkanalkarzinoms in einer multizentrischen Serie von 139 Patienten.

PURPOSE: Evaluation of prognostic variables, results and toxicity after chemo-radiation (CRT) of anal canal carcinoma (ACC). MATERIAL AND METHODS: Between 1982 and 1992, 139 patients with epidermoid carcinoma of the anal canal were treated by radiation and chemotherapy with 5-fluorouracil (5-Fu) and mitomycin C (MMC). 99 patients belonged to a prospectively designed trial (50 Gy, 2 courses of chemotherapy) and 40 to a historical control group (40 Gy, 1 course of chemotherapy). The female/male ratio was 116/23. Median age was 62 years. Staging (UICC 1987): T1: 16.5%; T2: 49%; T3: 23%; T4: 9.4%; unknown: 2.1%. Abnormal regional nodes were present in 15% of the patients. HISTOLOGY: Squamous cell carcinoma: 68%; cloacogenic carcinoma: 31%; unknown: 1%. External beam radiation (ERT) was given to the primary tumour including perirectal, inguinal and iliac nodes by a 3 to 4 field box technique (50 patients) or parallel opposed fields (89 patients). Median single fraction and total dose were 1.8 Gy and 50 Gy. An additional boost to the involved sites was delivered by ERT (32 cases; median dose 16 Gy) or interstitial brachytherapy (BT) in 28 cases with a median dose 14 Gy. 84 patients (60%) received 2 or more cycles, 50 patients (36%) 1 cycle, 5 patients (4%) no chemotherapy. RESULTS: The survival rate, NED-survival rate and local tumour control rate were 78%, 64% and 69% at 5 years. Anorectal function was retained in 94 of 139 patients (68%). Multivariate analysis indicated that T-stage (p = 0.037) and belonging to the historical control group (p = 0.003) were significant variables for local tumour control. T-stage was a marginally significant factor (p = 0.09) for NED-survival. Acute toxicity of grade 3 and 4 (WHO) was observed in 36%, severe late toxicity (grade 3 Eschwege) in 3% of the patients. CONCLUSIONS: CRT with 2 courses 5-FU, MMC and ERT to a total dose of 45 to 50 Gy is a safe and effective treatment for ACC. Intensification of treatment is recommended in advanced stages T3/4.

Digital storage phosphor radiography for treatment verification in radiotherapy.

The potential of digital storage phosphor radiography (SR) to improve image quality of portal radiographs is evaluated. Conventional film radiographs (FR) and corresponding SR verification images of an anthropomorphic phantom and various irradiation ports of patients were obtained with high-energy photon beams. For both techniques conventional films and storage phosphor screens were placed into a cassette with steel screens. Images were evaluated according to contrast and spatial resolution, delineation of anatomical structures, position of shielding blocks and accuracy of field alignments. Evaluation of 33 pairs of SR and FR portal images yielded a superior contrast resolution of SR in 47% (contrast air-soft tissue) and 37% (bone-soft tissue). Thus SR allows quick and easy detectability of anatomical structures as well as a better definition of block positions and field alignments. Shorter exposure times for computed images may result in a reduction of motion artefacts. SR images are indispensable in modern radiation therapy units, as they are instantly available in a computerized network for further image processing and analysis.

Preoperative systemic etoposide/ifosfamide/doxorubicin chemotherapy combined with regional hyperthermia in high-risk sarcoma: a pilot study.

From November 1990 to September 1991, 23 adults with high-risk, nonmetastatic sarcomas (20 soft-tissue sarcomas and 3 chondrosarcomas) were entered in a pilot protocol (RHT-91) involving regional hyperthermia combined with systemic chemotherapy followed by surgery. Of these patients, 12 had undergone previous surgery and/or radiation, 5 had received previous multidrug chemotherapy, and 6 were previously untreated. A tumor size of > 8 cm and/or an extracompartmental tumor location (11 patients) or local recurrence (12 patients) were defined as high-risk factors in addition to tumor grading (21 patients had grade 2 or 3 sarcomas). Regional hyperthermia was produced by an electromagnetic deep-regional-heating device. For systemic chemotherapy, all patients received etoposide/ifosfamide/doxorubicin (EIA) and mesna, with regional hyperthermia being given only on days 1 and 4 in repeated EIA/regional hyperthermia cycles every 3 weeks. Tumor temperatures (range, 40 degrees-44 degrees C) were measured by invasive thermometry in all patients during each regional hyperthermia treatment. A total of 181 regional hyperthermia treatments were applied within the pelvic region (11 patients) or extremities (12 patients) bearing relatively large tumors (mean volume, 848 cm3). By the cutoff date for this analysis (October 15, 1991), 13 patients had undergone surgery after receiving 2-6 (mean, 3.8) cycles of EIA chemotherapy combined with regional hyperthermia; all tumors except one were resected without disfiguration. In 22 evaluable patients (minimum, 2 EIA plus regional hyperthermia cycles), the clinical response rate was 27%, with 6 patients showing partial responses (PRs). In addition, a pathologic response to preoperative thermochemotherapy was evaluable in 13 patients, with 4 responders (31%) having > 50% histologic necrosis. In all, 3 of the responders (1 PR and 2 patients with > 50% histologic necrosis) relapsed within 3 months of surgical resection. The other 7 responding patients (5 PRs and 2 patients with > 50% histologic necrosis) showed stable disease with local tumor control. The study (RHT-91) is continuing as a multicenter phase II trial (opened on November 19, 1991) in patients with high-risk soft-tissue sarcomas to test the potential of preoperative thermochemotherapy in regard to local control and survival.

[Multiple admissions to the psychiatric hospital--a study of the status of so-called "revolving door patients"]. / Mehrfachaufnahmen im psychiatrischen Krankenhaus--eine Untersuchung zur Situation sogenannter "Drehtür-Patienten".

The graph of the frequency distribution of rehospitalization shows a constant exponential decline without demarking a particular population of so-called "revolving-door" patients. Patients with at least four admissions to a regional psychiatry hospital within a time span of two years are compared to a control group of the total clinic population. Multiple admission patients suffer significantly more often from diseases with an unfavourable prognosis, the illness has started earlier in their lives, and the course of illness is marked by unstable dynamic states with frequent crises of suicide. A demographic analysis shows the group under survey to be younger and less often married; participation in the world of labour has been lost more often, schizophrenics who have frequently stayed in hospitals even loose their former autonomy in housing. Guardianships are significantly more often installed, but they have not proved to be an efficient form of help. The therapeutic care of this problem patients is rather unsatisfactory. The offered ambulatory services are not claimed and in hospital the special treatment units fail to reach these patients. Lack of therapeutic continuity and compliance determines the course of treatment and complicates therapeutic strategies.

Antidepressant treatment of pathologic laughing or crying in elderly stroke patients.

Pathologic laughing or crying (PLC), a complication of many neurologic disorders, involves behavior that is either inappropriate to the context or to the patient's subjective feeling state. It is due to a dysregulation of the motoric components of emotional experience. PLC is distinct from, but often associated with, major depression. The relatively few reports on treatment of PLC are primarily with tricyclic antidepressants. We report the effective treatment of PLC due to stroke in three patients with nortriptyline or fluoxetine. The cases also illustrate the broad spectrum of depressive symptoms (from none to a major depression) seen in patients with PLC. We discuss treatment implications and directions for future research.

Persistent cortisol non-suppression after clinical recovery predicts symptomatic relapse in unipolar depression.

We assessed the length and the quality of remission of 13 unipolar endogenous depressed patients, DST non-suppressors before treatment, in a 2-year prospective study. During this period, we recorded stressful life events. Persistent dexamethasone non-suppression, after treatment and complete clinical recovery, correlated highly with early clinical relapse. All six non-normalizers but only one normalizer were rehospitalized within the following 2 years for a major depressive relapse. Persistent DST non-suppression was unrelated to any impact of drug discontinuation, the occurrence of stressful life events or the length of illness-free intervals in the patient's prior course of illness. Persistent DST non-suppression appears to have significant prognostic value.

Effect of methotrexate on perfusion and nitrogen-13 glutamate uptake in the Walker-256 carcinosarcoma.

The tissue uptake of [13N]glutamate (glu) was related to that of [11C]butanol (but), a highly diffusible perfusion tracer. In 25 rats bearing Walker-256 carcinomas tumor-to-muscle glu uptake averaged 6.34 +/- 2.84 (s.d.) prior to interventions and the respective uptake of but was 6.79 +/- 3.08 (y = 0.03 + 0.94x). One hour after selective intraarterial administration of methotrexate (mtx), glu uptake fell by 47%, whereas blood flow remained within the pretreatment range (N = 9). Four hours after mtx, perfusion was reduced by approximately 40%, and 2 days later both perfusion and glu uptake reached extremely low levels. No significant difference in the effect of 10 and 50 mg/kg mtx was observed. Regional tissue mtx uptake estimations using 77Br-labeled bromomethotrexate did not reveal any significant uptake in muscle. The relationship between tumor-to-muscle uptake of glu and but (13N/11C-index) was 0.94 +/- 0.015 (s.e.m., N = 25) before intervention. After methotrexate (1 hr, 4 hr, and 2 days) this index was 0.58 +/- 0.06 (N = 9), and 0.85 +/- 0.04 (N = 11) and 1.03 +/- 0.05 (N = 5), respectively. These values demonstrate an early mtx-induced uncoupling of glu uptake with respect to perfusion.

Nitrogen-13 glutamate uptake and perfusion in Walker 256 carcinosarcoma before and after single-dose irradiation.

Nitrogen-13 (13N) glutamate uptake was recorded in 18 anesthetized rats, both before and at least once after intervention. Each investigation was immediately followed by imaging of blood flow distribution using [11C]butanol. All animals had Walker 256 carcinosarcoma implants in one hind leg. Tumors were locally irradiated with a dose of 800 rad in 14 rats; in four rats, the vasoactive substance 5-hydroxytryptamine (5-HT) was administered. Prior to interventions, the [13N]glutamate tumor-to-muscle uptake showed a linear correlation with blood flow close to identity (y = 0.117 + 0.915x, r = 0.97). After irradiation, a discordant pattern was observed: blood flow tended to increase, while [13N]glutamate tumor-to-muscle uptake dropped from 4.30 +/- 0.66 (s.e.m.) to 3.06 +/- 0.36 (p less than 0.005) during 30 min and attained 4.04 +/- 0.67 2 days later. If [13N]glutamate tumor-to-muscle uptake was related to that of [11C] butanol in each individual animal, this index dropped from 0.93 +/- 0.03 (s.e.m.) to 0.62 +/- 0.04 (p less than 0.001) 30 min after irradiation and attained 0.90 +/- 0.09 after 2 days. In animals treated with 5-HT, [13N]glutamate and [11C]butanol showed a parallel drop from 6.60 +/- 0.84 to 2.10 +/- 0.60 (p less than 0.05) and from 6.8 +/- 0.78 to 2.08 +/- 0.74 (p less than 0.05), respectively. Thus, single-dose irradiation causes [13N]glutamate uptake to be uncoupled with respect to flow, while [13N]glutamate uptake in untreated tumors is flow-limited and responds together with flow on vasomotion.

Whole-body autoradiographic studies in rats with gadolinium-diethylenetriaminepentaacetic acid, a new contrast agent for magnetic resonance imaging.

The time course of the distribution of radiolabel in organs and tissues was investigated after intravenous administration of 0.5 mmol/kg of 14C-labelled gadolinium-diethylenetriaminepentaacetic acid (Gd-14C-DTPA) and of 153Gd-DTPA to pregnant rats (18th day p.c.) and after intragastric administration of 30 mumol/kg of Gd-14C-DTPA to male rats by whole-body autoradiographic technique. After intravenous administration Gd-DTPA was rapidly distributed within the organism. The distribution pattern was similar to that of classical X-ray contrast agents like diatrizoate and iotalamic acid. Gd-DTPA was not able to pass blood-brain and placental barriers. There was no indication of a dissociation of Gd-DTPA complex. 24 h after i.v. injection most of the radiolabel left the body. Only very small amounts were found in the kidney, the placenta and in the contents of the intestine. No specific and long-lasting retention of radioactivity was observed in any organ and tissue. After intragastric administration Gd-DTPA was not absorbed.