Extreme ultraviolet-excited time-resolved luminescence spectroscopy using an ultrafast table-top high-harmonic generation source

We present a table-top extreme ultraviolet (XUV) beamline for measuring time- and frequency-resolved XUV-excited optical luminescence (XEOL) with additional femtosecond-resolution XUV transient absorption spectroscopy functionality. XUV pulses are generated via high-harmonic generation using a near-infrared pulse in a noble gas medium and focused to excite luminescence from a solid sample. The luminescence is collimated and guided into a streak camera where its spectral components are temporally resolved with picosecond temporal resolution. We time-resolve XUV-excited luminescence and compare the results to luminescence decays excited at longer wavelengths for three different materials: (i) sodium salicylate, an often used XUV scintillator; (ii) fluorescent labeling molecule 4-carbazole benzoic (CB) acid; and (iii) a zirconium metal oxo-cluster labeled with CB, which is a photoresist candidate for extreme-ultraviolet lithography. Our results establish time-resolved XEOL as a new technique to measure transient XUV-driven phenomena in solid-state samples and identify decay mechanisms of molecules following XUV and soft-x-ray excitation.

[A structured pain interview for geriatric patients]

BACKGROUND

In old age, assessment of pain often is hampered by sensory and cognitive deficits that do not allow the patients to fill in standardized questionnaires without help from significant others. Therefore, as an alternative, we developed a structured pain interview, and examined its properties and acceptance in a sample of geriatric patients with pain.

METHODS

The interview covers site of pain, intensity of pain, its duration and persistency, pain related disability and, finally, emotional and cognitive variables. In addition, the interviewer addresses significant others to get information about medication, previous treatment, and residence, and administers the Mini-Mental-State-Examination (MMSE). The analysis includes 128 patients of pain centers older than 74 years, of whom 80% are female.

RESULTS

Forty percent of the subjects score below the critical MMSE value < or =23 indicative of cognitive impairment. These patients are responsible for 36 out of a total of 39 missing values. A significant increase of missing values is observed in patients with a MMSE score below 10. Cognitive impairment goes along with greater functional and social disability. On the other hand, cognitive impairment is unrelated to localization, intensity, and duration of pain. The memory item of the MMSE can be used as a screening tool for cognitive impairment. Patients, who are unable to recall any of the three objects, comprise 80% of the total of missing values and demonstrate a low MMSE score.

CONCLUSION

As long as geriatric patients are able to communicate verbally, they are most likely to profit from the structured pain interview in spite of existing cognitive impairment. A MMSE score <10 indicates that the interpretation of the data obtained may be difficult, especially due to a high frequency of missing values.

[Negative priming designs: comparison and improvement of measurements for detection of cognitive inhibition]

Ignoring a distractor on a prime trial generally impairs responses to that stimulus on a subsequent probe trial. This so called negative-priming (NP) effect supports the view that the representations of distracting stimuli underly a cognitive inhibition during target selection (Tipper, 1985). Aiming at the optimization of NP designs for analyzing cognitive inhibition the present paper investigates two open questions within this context: Which classical designs using words, letters, or pictures as stimuli are most accepted by subjects and at the same time result in possibly strong NP effects? What is the time course of NP, and at which interstimulus interval (ISI) the maximum is reached? In experiment 1, three "classical" NP designs were compared within one sample of subjects and a picture design was selected as the most suitable one. In experiment 2 the ISI was varied within subjects; the maximal NP effect was found at an ISI of around 1000 ms.

Perioperative blood transfusion and cancer prognosis. Different effects of blood transfusion on prognosis of colon and breast cancer patients

A detailed retrospective analysis was undertaken of the effect of perioperative blood transfusion on long-term survival of 113 patients with Dukes' Stages A, B and C1 cancer of the colon and 383 patients with invasive cancer of the breast who were treated in our institution between 1973 and 1978 and followed for 5 to 10 years. In the patients with colon cancer, a significant adverse effect of transfusion on long-term survival was seen. In this group there was a cumulative 5-year overall survival of 48% for the transfused and 74% for the nontransfused patients (P = 0.007, log-rank test). Perioperative blood transfusion was associated with a relative risk of 3.42 for all deaths (P = 0.005) and 4.25 for death due to cancer (P = 0.03), after adjustment for other important variables such as age, sex, stage, location of tumor, surgical procedure, and preoperative hemoglobin level. In contrast, in our study group of patients with breast cancers, who all underwent a modified radical mastectomy, no effect of blood transfusion on long-term survival was seen. Multivariate analysis adjusting for size of tumor, number of positive regional lymph nodes, menopausal status, estrogen receptor status and the addition or absence of chemotherapy, did not show any increased risk in all deaths or death due to cancer associated with blood transfusion. Although no definite explanation is available, our data show that there seems to be a difference in the relationship between perioperative blood transfusion and survival for colon and breast cancer patients.

Cell kinetic behaviour of a synchronized population of erythroid precursor cells in vitro

Erythropoiesis in vitro was studied with practically pure erythroid progenitor cells: CFU-E (colony-forming-units-erythroid). The isolation of CFU-e from spleens of thiamphenicol pretreated anaemic mice with the combined methods of centrifugal elutriation and Percoll density gradient centrifugation was monitored by flow cytometry. The ultimate CFU-e preparation with a density of 1.070 g/ml contained a high percentage of cells in the S phase of the cell cycle (80%). CFU-e occasionally found at a lower density of 1.065 g/ml were predominantly in the G2 + M and G1 phases. When CFU-e were cultured, the number of cells in the distinctive phases of the cell cycle changed periodically, so the cells were partly synchronized. Four periods up to 27 hr were observed by flow cytometrical screening of the cultured cells at hourly intervals. Cell-cycle times between 6 and 7 hr were found for all erythroid cell divisions. This was in agreement with results obtained from colony growth curves. Without the addition of erythropoietin cells start to degenerate after the second cell division. This experimental approach can be used for the cell kinetic modelling of erythropoiesis.