Question prompts to empower cancer patients: results of a randomized controlled trial.

OBJECTIVE: In addition to question prompts for information transfer, we also used prompts to facilitate the expression of emotions. Our aim was to investigate how a question prompt list (QPL) is accepted by patients and whether it enhances interactional empowerment of the patients in the consultation with the radio-oncological treatment team before the beginning of radiotherapy. METHODOLOGY: Adult cancer patients before the beginning of radiotherapy were randomly assigned to the intervention group (IG) or control group (CG). The patients in the IG received a QPL with predefined subsets and subject areas. After the physician's consultation, both groups completed a self-developed, content validated questionnaire on interactional empowerment. The IG evaluated the QPL using a self-developed instrument. RESULT: A total of 279 adult cancer patients participated in the study (IG n = 139/CG n = 140). The participants of the IG reported a significantly higher interactional empowerment compared with those of the CG (t(277) = - 2.71, p = .007, 95% CI [- 1.61, - 0.26], d = 0.29). 60.4% of the IG agreed "rather" or "very" that they used the QPL in consultation with the medical team. CONCLUSION: The QPL used in the consultation improved the self-assessed competence for interaction with the medical team and strengthened the interactional empowerment. The QPL was well accepted by the patients and is to be introduced into a routine as a practicable and simple instrument in the future. The support of patients in addressing concerns and fears is an important innovation.

X-ray reflectivity measurement of interdiffusion in metallic multilayers during rapid heating.

A technique for measuring interdiffusion in multilayer materials during rapid heating using X-ray reflectivity is described. In this technique the sample is bent to achieve a range of incident angles simultaneously, and the scattered intensity is recorded on a fast high-dynamic-range mixed-mode pixel array detector. Heating of the multilayer is achieved by electrical resistive heating of the silicon substrate, monitored by an infrared pyrometer. As an example, reflectivity data from Al/Ni heated at rates up to 200 K s-1 are presented. At short times the interdiffusion coefficient can be determined from the rate of decay of the reflectivity peaks, and it is shown that the activation energy for interdiffusion is consistent with a grain boundary diffusion mechanism. At longer times the simple analysis no longer applies because the evolution of the reflectivity pattern is complicated by other processes, such as nucleation and growth of intermetallic phases.

Multi-scale time-resolved electron diffraction: A case study in moiré materials.

Ultrafast-optical-pump - structural-probe measurements, including ultrafast electron and x-ray scattering, provide direct experimental access to the fundamental timescales of atomic motion, and are thus foundational techniques for studying matter out of equilibrium. High-performance detectors are needed in scattering experiments to obtain maximum scientific value from every probe particle. We deploy a hybrid pixel array direct electron detector to perform ultrafast electron diffraction experiments on a WSe2/MoSe2 2D heterobilayer, resolving the weak features of diffuse scattering and moiré superlattice structure without saturating the zero order peak. Enabled by the detector's high frame rate, we show that a chopping technique provides diffraction difference images with signal-to-noise at the shot noise limit. Finally, we demonstrate that a fast detector frame rate coupled with a high repetition rate probe can provide continuous time resolution from femtoseconds to seconds, enabling us to perform a scanning ultrafast electron diffraction experiment that maps thermal transport in WSe2/MoSe2 and resolves distinct diffusion mechanisms in space and time.

Proliferating dendritic cell progenitors in human blood.

CD34+ cells in human cord blood and marrow are known to give rise to dendritic cells (DC), as well as to other myeloid lineages. CD34+ cells are rare in adult blood, however, making it difficult to use CD34+ cells to ascertain if DC progenitors are present in the circulation and if blood can be a starting point to obtain large numbers of these immunostimulatory antigen-presenting cells for clinical studies. A systematic search for DC progenitors was therefore carried out in several contexts. In each case, we looked initially for the distinctive proliferating aggregates that were described previously in mice. In cord blood, it was only necessary to deplete erythroid progenitors, and add granulocyte/macrophage colony-stimulating factor (GM-CSF) together with tumor necrosis factor (TNF), to observe many aggregates and the production of typical DC progeny. In adult blood from patients receiving CSFs after chemotherapy for malignancy, GM-CSF and TNF likewise generated characteristic DCs from HLA-DR negative precursors. However, in adult blood from healthy donors, the above approaches only generated small DC aggregates which then seemed to become monocytes. When interleukin 4 was used to suppress monocyte development (Jansen, J. H., G.-J. H. M. Wientjens, W. E. Fibbe, R. Willemze, and H. C. Kluin-Nelemans. 1989. J. Exp. Med. 170:577.), the addition of GM-CSF led to the formation of large proliferating DC aggregates and within 5-7 d, many nonproliferating progeny, about 3-8 million cells per 40 ml of blood. The progeny had a characteristic morphology and surface composition (e.g., abundant HLA-DR and accessory molecules for cell-mediated immunity) and were potent stimulators of quiescent T cells. Therefore, large numbers of DCs can be mobilized by specific cytokines from progenitors in the blood stream. These relatively large numbers of DC progeny should facilitate future studies of their Fc epsilon RI and CD4 receptors, and their use in stimulating T cell-mediated resistance to viruses and tumors.

Time-resolved x-ray diffraction of biological materials.

Instrumental and specimen considerations pertinent to performing time-resolved x-ray diffraction on biological materials are discussed. Existing synchrotron x-ray sources, in conjunction with integrating x-ray detectors, have made millisecond diffraction experiments feasible; exposure times several orders of magnitude shorter than this will be possible with synchrotron sources now on the drawing boards. Experience gained from time-resolved studies together with order-of-magnitude estimates of specimen requirements can be used to determine the instrumental capabilities needed for various time-resolved experiments. Existing instrumental capabilities and methods of dealing with time-resolved specimens are reviewed.

Role of lipid polymorphism in pulmonary surfactant.

The development of artificial surfactants for the treatment of respiratory distress syndrome (RDS) requires lipid systems that can spread rapidly from solution to the air-water interface. Because hydration-repulsion forces stabilize liposomal bilayers and oppose spreading, liposome systems that undergo geometric rearrangement from the bilayer (lamellar) phase to the hexagonal II (HII) phase could hasten lipid transfer to the air-water interface through unstable transition intermediates. A liposome system containing dipalmitoylphosphatidylcholine was designed; the system is stable at 23 degrees C but undergoes transformation to the HII phase as the temperature increases to 37 degrees C. The spreading of lipid from this system to the air-water interface was rapid at 37 degrees C but slow at 23 degrees C. When tested in vivo in a neonatal rabbit model, such systems elicited an onset of action equal to that of native human surfactant. These findings suggest that lipid polymorphic phase behavior may have a crucial role in the effective functioning of pulmonary surfactant.

A high-speed area detector for novel imaging techniques in a scanning transmission electron microscope.

A scanning transmission electron microscope (STEM) produces a convergent beam electron diffraction pattern at each position of a raster scan with a focused electron beam, but recording this information poses major challenges for gathering and storing such large data sets in a timely manner and with sufficient dynamic range. To investigate the crystalline structure of materials, a 16x16 analog pixel array detector (PAD) is used to replace the traditional detectors and retain the diffraction information at every STEM raster position. The PAD, unlike a charge-coupled device (CCD) or photomultiplier tube (PMT), directly images 120-200keV electrons with relatively little radiation damage, exhibits no afterglow and limits crosstalk between adjacent pixels. Traditional STEM imaging modes can still be performed by the PAD with a 1.1kHz frame rate, which allows post-acquisition control over imaging conditions and enables novel imaging techniques based on the retained crystalline information. Techniques for rapid, semi-automatic crystal grain segmentation with sub-nanometer resolution are described using cross-correlation, sub-region integration, and other post-processing methods.

Segregation and temperature effect on the atomic structure of Bi(30)Ga(70) liquid alloy.

We investigate the structure of liquid monotectic alloy Bi(30)Ga(70) above and below the critical point. The three-dimensional structure at 265 °C is modelled by means of the reverse Monte Carlo simulation technique using neutron and x-ray diffraction experimental data. It is shown that atomic segregation on the short-range scale exists in the liquid Bi(30)Ga(70) slightly above the critical temperature (T(C) = 262 °C). We present also the structure factors of Bi(30)Ga(70) liquid alloy under the critical point at 240 and 230 °C obtained with neutron diffraction to highlight the temperature effect in the atomic structure.

Intermittent plasticity in individual grains: A study using high energy x-ray diffraction.

Long-standing evidence suggests that plasticity in metals may proceed in an intermittent fashion. While the documentation of intermittency in plastically deforming materials has been achieved in several experimental settings, efforts to draw connections from dislocation motion and structure development to stress relaxation have been limited, especially in the bulk of deforming polycrystals. This work uses high energy x-ray diffraction measurements to build these links by characterizing plastic deformation events inside individual deforming grains in both the titanium alloy, Ti-7Al, and the magnesium alloy, AZ31. This analysis is performed by combining macroscopic stress relaxation data, complete grain stress states found using far-field high energy diffraction microscopy, and rapid x-ray diffraction spot measurements made using a Mixed-Mode Pixel Array Detector. Changes in the dislocation content within the deforming grains are monitored using the evolution of the full 3-D shapes of the diffraction spot intensity distributions in reciprocal space. The results for the Ti-7Al alloy show the presence of large stress fluctuations in contrast to AZ31, which shows a lesser degree of intermittent plastic flow.

Experimental 3D coherent diffractive imaging from photon-sparse random projections.

The routine atomic resolution structure determination of single particles is expected to have profound implications for probing structure-function relationships in systems ranging from energy-storage materials to biological molecules. Extremely bright ultrashort-pulse X-ray sources - X-ray free-electron lasers (XFELs) - provide X-rays that can be used to probe ensembles of nearly identical nanoscale particles. When combined with coherent diffractive imaging, these objects can be imaged; however, as the resolution of the images approaches the atomic scale, the measured data are increasingly difficult to obtain and, during an X-ray pulse, the number of photons incident on the 2D detector is much smaller than the number of pixels. This latter concern, the signal 'sparsity', materially impedes the application of the method. An experimental analog using a conventional X-ray source is demonstrated and yields signal levels comparable with those expected from single biomolecules illuminated by focused XFEL pulses. The analog experiment provides an invaluable cross check on the fidelity of the reconstructed data that is not available during XFEL experiments. Using these experimental data, it is established that a sparsity of order 1.3 × 10-3 photons per pixel per frame can be overcome, lending vital insight to the solution of the atomic resolution XFEL single-particle imaging problem by experimentally demonstrating 3D coherent diffractive imaging from photon-sparse random projections.

Thermoregulation in larval aggregations of carrion-feeding blow flies (Diptera: Calliphoridae).

The growth and development of carrion-feeding calliphorid (Diptera: Calliphoridae) larvae, or maggots, is of great interest to forensic sciences, especially for estimation of a postmortem interval (PMI). The development rate of calliphorid larvae is influenced by the temperature of their immediate environment. Heat generation in larval feeding aggregations (=maggot masses) is a well-known phenomenon, but it has not been quantitatively described. Calculated development rates that do not include internally generated temperatures will result in overestimation of PMI. Over a period of 2.5 yr, 80 pig, Sus scrofa L., carcasses were placed out at study sites in north central Florida and northwestern Indiana. Once larval aggregations started to form, multiple internal and external temperatures, and weather observations were taken daily or every few days between 1400 and 1800 hours until pupation of the larvae. Volume of each aggregation was determined by measuring surface area and average depth. Live and preserved samples of larvae were taken for species identification. The four most common species collected were Lucilia coeruleiviridis (=Phaenicia) (Macquart) (77%), Cochliomyia macellaria (F.) (8.3%), Chrysomya rufifaces (Macquart) (7.7%), and Phormnia regina (Meigen) (5.5%). Statistical analyses showed that 1) volume of a larval mass had a strong influence on its temperature, 2) internal temperatures of masses on the ground were influenced by soil temperature and mass volume, 3) internal temperatures of masses smaller than 20 cm3 were influenced by ambient air temperature and mass volume, and 4) masses larger than 20 cm3 on the carcass had strongly regulated internal temperatures determined only by the volume of the mass, with larger volumes associated with higher temperatures. Nonsignificant factors included presence of rain or clouds, shape of the aggregation, weight of the carcass, species composition of the aggregation, time since death, or season.

Atomic structure of As(25)Si(40)Te(35) glass.

Glassy As(25)Si(40)Te(35) has been studied by x-ray and neutron diffraction as well as x-ray absorption spectroscopy (EXAFS) at As and Te K-edges. Simultaneous modelling of the four independent measurements by means of the reverse Monte Carlo (RMC) simulation technique allowed the separation of partial pair distribution functions and estimation of the corresponding coordination numbers. It is shown that the atomic structure of As(25)Si(40)Te(35) glass can be presented as a three-dimensional network of twofold coordinated Te, threefold coordinated As and fourfold coordinated Si atoms.

Development of the Oriental Latrine Fly, Chrysomya megacephala (Diptera: Calliphoridae), at Five Constant Temperatures.

Chrysomya megacephala (Fabricius) is a forensically important fly that is found throughout the tropics and subtropics. We calculated the accumulated development time and transition points for each life stage from eclosion to adult emergence at five constant temperatures: 15, 20, 25, 30, and 35 °C. For each transition, the 10th, 50th, and 90th percentiles were calculated with a logistic linear model. The mean transition times and % survivorship were determined directly from the raw laboratory data. Development times of C. megacephala were compared with that of two other closely related species, Chrysomya rufifacies (Macquart) and Phormia regina (Meigen). Ambient and larval mass temperatures were collected from field studies conducted from 2001-2004. Field study data indicated that adult fly activity was reduced at lower ambient temperatures, but once a larval mass was established, heat generation occurred. These development times and durations can be used for estimation of a postmortem interval (PMI).

Volume of Larvae Is the Most Important Single Predictor of Mass Temperatures in the Forensically Important Calliphorid, Chrysomya megacephala (Diptera: Calliphoridae).

Calliphorid species form larval aggregations that are capable of generating heat above ambient temperature. We wanted to determine the relationship between volume, number of larvae, and different combinations of instars on larval mass heat generation. We compared different numbers of Chrysomya megacephala (F.) larvae (40, 100, 250, 600, and 2,000), and different combinations of instars (∼50/50 first and second instars, 100% second instars, ∼50/50 second and third instars, and 100% third instars) at two different ambient temperatures (20 and 30 °C). We compared 13 candidate multiple regression models that were fitted to the data; the models were then scored and ranked with Akaike information criterion and Bayesian information criterion. The results indicate that although instar, age, treatment temperature, elapsed time, and number of larvae in a mass were significant, larval volume was the best predictor of larval mass temperatures. The volume of a larval mass may need to be taken into consideration for determination of a postmortem interval.

High-resolution macromolecular structure determination using CCD detectors and synchrotron radiation.

BACKGROUND: Synchrotron radiation sources have made impressive contributions to macromolecular crystallography. The delay in development of appropriate X-ray detectors has, however, been a significant limitation to their efficient use. New technologies, based on charge-coupled devices (CCDs), provide capabilities for faster, more accurate, automated data collection. RESULTS: A CCD-based X-ray detector has been developed for use in macromolecular crystallography and has been in operation for about one and a half years at the Cornell High Energy Synchrotron Source. It has been used for a variety of crystallographic projects, including a number of high-resolution structural studies. The statistical quality of the data, the detector's ease and efficiency of use, and the growing number of structural results illustrate the practical utility of this new detector system. CONCLUSIONS: The new detector has enhanced capabilities for measuring diffraction patterns from crystals of macromolecules, especially at high resolution, when the X-ray intensities are weak. The survey of results described here ranges from virus crystallography to weakly diffracting small-molecule structure determination and demonstrates the potential of CCD detectors when combined with synchrotron radiation sources.

X-ray diffraction demonstrates that phosphatidyldiacylglycerol and phosphatidylcholesterol are not lamellar above the main transition temperature.

X-ray diffraction was used to investigate the lattice structure of aqueous dispersions of two phosphatidyldiacylglycerols and of a phosphatidylcholesterol above and below the chain melting transition temperature. Previously, Noggle et al. (Biochim. Biophys. Acta (1982) 691, 240-248) had investigated these lipids and had concluded on the basis of electron microscopy that the lipids were in a lamellar state above the transition temperature. However, they found the 31P-NMR signals were not characteristic of lamellar phases. It was, therefore, concluded that these lipids were yielding unexpected 31P-NMR spectra. The present X-ray results demonstrate that, in fact, the lipids are not in a lamellar state above the transition temperature and that the 31P-NMR and X-ray data are not necessarily in disagreement. Characteristics of the phases both above and below the chain melt temperature are discussed.

A 12 A resolution X-ray diffraction study of the profile structure of isolated bovine retinal rod outer segment disk membranes.

Electron density profiles of disk membranes isolated from bovine retinal rod outer segments have been determined to 12 A resolution by analysis of the X-ray diffraction from oriented multilayers, in the absence of lipid phase separation. Data were collected on both film and a two-dimensional TV-detector; both detectors yielded identical patterns consisting of relatively sharp lamellar reflections of small mosaic spread. The unit cell repeat was reversibly varied over the range of 143 to 183 A. The diffraction patterns changed dramatically at 150 A; consequently, the low (less than 150 A) and high (greater than 150 A) periodicity data were independently analyzed via a swelling algorithm. The high periodicity data yielded two statistically equivalent phase choices corresponding to two symmetric, but different membrane profiles. The low periodicity data yielded essentially one, characteristically asymmetric profile. These profiles have been modeled with regard to the separate profiles of rhodopsin, lipid and water, subject to the known composition of the isolated disk membranes.

Small concentrations of alamethicin induce a cubic phase in bulk phosphatidylethanolamine mixtures.

Under normal conditions, excess water dispersions of liquid crystalline 1,2-dielaidoyl-sn-glycero-3- phosphoethanolamine (DEPE) are known to convert from a liquid crystalline lamellar (L alpha) to inverse hexagonal (HII) phase at about 60 degrees Celsius. The nonlamellar phase behavior of lipid systems is also known to depend on the monolayer spontaneous curvature. The single-channel activity of alamethicin in black lipid bilayer membranes has been shown to be dependent upon the lipid composition of the membrane. Since the monolayer spontaneous curvature properties (e.g., the monolayer spontaneous curvature, curvature coefficients and bilayer thickness) vary with lipid composition, the single-channel activity of alamethicin presumably also correlates with the monolayer spontaneous curvature properties. Accordingly, we reasoned that if alamethicin couples to the curvature properties of a lipid film, then the curvature properties must, in turn, be perturbed by the presence of alamethicin and that this perturbation should be observable in the lipid phase behavior. Here X-ray diffraction and NMR are used to show that the presence of as little as 1% alamethicin introduces a large region of cubic phase into the thermal phase diagram. This suggests that perturbation of the nonlamellar phase behavior of a lipid system may be a method to survey different channel-forming molecules for possible behavior that indicates that the ion channel is sensitive to the monolayer spontaneous curvature properties.

Lipid extracts from membranes of Acholeplasma laidlawii A grown with different fatty acids have a nearly constant spontaneous curvature.

X-ray diffraction methods were used to explore the variation in the spontaneous curvature of lipid extracts from Acholeplasma laidlawii strain A-EF22 grown with different mixtures of palmitic acid and oleic acid. It was shown that the cells respond to the different growing conditions by altering the polar head group compositions in order to keep the phase transition between lamellar and nonlamellar structures within a narrow temperature range. This has been interpreted to mean that the membrane lipids are adjusted toward an optimal packing (Lindblom et al. (1986) Biochemistry 25, 7502). Here it is shown that for these extracts, the membrane curvature is kept within a narrow range (58-73 A), compared to the range in curvatures exhibited by pure lipids extracts from the membrane (17-123 A). These observations support the hypothesis (Gruner (1989) J. Phys. Chem. 93, 7562) that the spontaneous curvature is a functionally important membrane parameter which is regulated by the organism and is likely to be one of the constraints controlling the lipid composition of the bilayer.