Search Results - (Author, Cooperation:M. Pfeifer)

2012-11-30

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Brachypodium/genetics ; *Bread ; Chromosomes, Plant/genetics ; Crops, Agricultural/genetics ; DNA, Complementary/genetics ; DNA, Plant/genetics ; Evolution, Molecular ; Genes, Plant/genetics ; Genome, Plant/*genetics ; Genomics ; Multigene Family/genetics ; Oryza/genetics ; Polymorphism, Single Nucleotide/genetics ; Polyploidy ; Pseudogenes/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Triticum/classification/*genetics ; Zea mays/genetics

2013-03-29

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Adaptation, Physiological/*genetics ; Brachypodium/genetics ; Chromosome Mapping ; Chromosomes, Plant/genetics ; DNA Transposable Elements/genetics ; Disease Resistance/genetics ; Genes, Plant/genetics ; Genome, Plant/*genetics ; Hordeum/genetics ; Molecular Sequence Data ; Plant Diseases ; Poaceae/*genetics ; Polyploidy ; Sequence Analysis, RNA ; Transcription Factors/genetics ; Triticum/*genetics/physiology

2014-07-19

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

*Bread ; *Evolution, Molecular ; Genes, Plant ; *Genome, Plant ; *Hybridization, Genetic ; Phylogeny ; Polyploidy ; Triticum/classification/*genetics

2014-07-19

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

*Bread ; Edible Grain/genetics ; Endosperm/genetics ; Gene Dosage ; Gene Expression Regulation, Plant ; *Genome, Plant ; Plant Proteins/genetics ; *Polyploidy ; Transcriptome ; Triticum/*genetics

2014-07-26

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; *Animals, Wild ; *Biodiversity ; *Conservation of Natural Resources ; *Ecosystem ; Humans

2018-08-17

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Botany, Ecology, Online Only

1089-7674

AIP Digital Archive

Physics

The Prague Asterix Laser System (PALS) is a new international laboratory where research teams are invited to compete for the beam time. The PALS Center runs an iodine photodissociation high-power laser system delivering up to 1.2 kJ of energy in ∼400 ps pulses at the wavelength of 1.315 μm. Optional doubling and tripling of the frequency is assured by large-diameter nonlinear crystals. The ASTERIX IV laser [H. Baumhacker et al., Appl. Phys. B 61, 325 (1995)], transferred from Garching into a new laser hall in Prague, was updated and put into operation on 8 June 2000. These upgrades include new beam delivery options and a twin interaction chamber, which is designed flexibly for a broad spectrum of applications. Results of the first series of experiments are presented and some planned upgrades are briefly described. These include implementation of adaptive optics, replacement of the iodine master oscillator by a more flexible solid state oscillator based on fiber optics, and a femtosecond extension of the laser output to reach the petawatt pulse power region. © 2001 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

The results of experimental investigations on ion production from tantalum targets, made with the application of the Thomson parabola ion spectrograph (TP) to an image converter equipped with a microchannel plate of the size of 70×90 mm2, are presented. In the experiments, the iodine photodissociation laser system PERUN (λ=1.315 μm, EL≤50 J, τ∼350–650 ps. I≤1015 W/cm2) was used for ion generation. The TP can give useful information about physical processes, ion species, their energies, and charge states from a single laser shot. The results obtained are compared with the results of measurements made with an electrostatic ion energy analyzer and charge collectors and they are used to estimate the Ta ion yield with an average charge state of 40+. The obtained values are N∼2.6×1011 sr−1. © 1996 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Results of experiments on ion production from Ta target using ∼350 ps pulses of the iodine photodissociation laser PERUN are presented and analysed. Ta ions with charge states higher than 45+ and with energies 8 MeV were registered in a far expansion zone (∼2 m). Theoretical interpretation of the results is possible by considering that the plasma temporal evolution follows the mechanism of two-temperature isothermal expansion. © 1996 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Properties of laser produced stream of ions of high- and medium-Z elements were analyzed in the far expansion zone using time-of-flight method and Thomson parabola spectrograph in experiments performed with the iodine laser system PERUN at IP ASCR, Prague (λ=1.315 μm, EL∼45 J,τL∼300–700 μs). Ta, Au, and Pb, as well as Co, Sn, and Ag were mainly used as targets onto which a laser power density up to 1×1015 W cm−2 was delivered. Attention is paid to the evolution and comparison of different produced ion groups, and to the number, charge state, energy, and angular distribution of emitted ions. © 2000 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Multiply charged ions of Ta, W, Pt, Au, Pb, and Bi, produced by the photodissociation iodine laser system PERUN (λ=1.315 μm, EL〈40 J, τL∼350 ps) are reported. The ions with maximum charge states around 50+ and with energies of several MeV were registered at a distance of about 2 m from a plasma plume. The existence of several groups of ions corresponds to the different processes that occur in the plasma. The influence of different factors on the ion production is discussed. Measured ion current densities higher than 10 mA/cm2 in the distance of 1 m from the target demonstrate the superiority of laser ion sources. © 1998 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Results of generation of intense currents of highly charged ions of heavy elements from laser-produced Au, Pb, and Ta plasmas are reported. High-power iodine laser PERUN operating with λ=1.315 μm was used for that purpose. Using a parabolic mirror with a hole in the center instead of a focusing lens increased the efficiency of the illumination system and made the ion measurements along the target normal possible. Multiply charged ions were recorded with an ion energy analyzer in a distance of 240 cm. © 1996 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Changes in the ion population during the expansion of Ag, Cu, Pb, and Ta laser-produced plasmas in vacuum were simultaneously measured with two coaxial ion collectors between 82 and 187 cm from a target. The plasma was produced with an iodine laser delivering a power density up to ∼1015 W/cm2 onto the target. It was experimentally proved that the charge Q of expanding ions and the corresponding ion current density j are really decreasing with the distance L as Q∝L−2 and j∝L−3, respectively. It implies that the "freezing" of charge states dominates in that interval of L. © 1999 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Angular distribution of ion currents emitted from laser-produced plasmas are reported for a Nd:YAG laser with intensities lower than 1×1010 W/cm2. This distributions are strongly peaked along the normal to the target surface for Cu, Sn, Ta, W, Au, and Pb ion streams, independent of the incidence angle of the irradiated target. For Al, Ni, and Nb the main axis tends to decline to about −10°. The comparison of fits of Gaussian function and cosP(α−α0)+y0 to the experimental data verified the formal equivalency of both the functions. Fitted values of the FWHM and of the exponent P are compared for all the elements used. The angular distribution of mean ion velocity 〈v〉 and ion kinetic energy 〈E〉 are presented. © 2002 American Institute of Physics.

Electronic Resource

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Lipopolysaccharide (LPS) as a major component of the outer membrane of gram-negative bacteria stimulates various cells to initiate a signalling cascade which ultimately leads to cell activation and expression of immunoregulatory or inflammatory cytokines. The human respiratory epithelium is an important environmental interface, but differences in LPS-induced cell activation between bronchial and alveolar epithelial cells have not yet been investigated in detail. First, the expression of Toll-like receptors (TLRs), as pattern-recognition receptors, was investigated for the bronchial epithelial cells and type II-like pneumocytes, demonstrating that they fulfil the prerequisites for LPS signalling. Thereafter, the effects of LPS, soluble CD14 (sCD14) and LPS-binding protein (LBP) on the release of interleukin-6 (IL-6) and IL-8 were studied. In the presence of LPS, sCD14 induced a significant and concentration-dependent cytokine release in type II-like pneumocytes, whereas the response of bronchial epithelial cells to sCD14 stimulation was low, implicating sCD14-independent activation mechanisms. Furthermore, LBP revealed inhibitory effects on the activation of alveolar epithelial cells, which may represent a novel local defence mechanism during gram-negative infection. We conclude that distinct pathways exist for LPS-induced activation of bronchial and alveolar epithelial cells.

Electronic Resource

0021-9673

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1433-2965

Key words:Pain – Postmenopausal osteoporosis – Quality of life – Rehabilitative care – Vertebral fractures – Well-being

Springer Online Journal Archives 1860-2000

Medicine

Abstract: The aim of the study was to identify factors affecting patients with postmenopausal osteoporosis who had experienced one or more vertebral fractures. The overall hypothesis was that time after fracture would influence patients’ perception of pain and well-being. The sample (50 patients) was split into two groups (group A, time after fracture ≤24 months; group B, time after fracture 〉24 months). A fracture was defined as a vertebral height reduction of more than 20% or at least 4 mm. The assessment was carried out using the Spine Deformity Index and was confirmed by an experienced radiologist. To assess quality of life (QoL) the following measures were used: ‘well-being scale’ including social extroversion as a subscale, pain scale, and limitations in everyday life. The Sense of Coherence questionnaire developed by Antonovsky measures the ability of a person to see life meaningful, manageable and explicable. This questionnaire may reflect patients’ coping abilities and was introduced to establish whether these influence the perception of pain and well-being after vertebral fracture. Variance and covariance analysis was carried out using SPSS (version 6.1). Differences between groups A and B were found for perception of average pain (p = 0.017), social extroversion (p = 0.003) and well-being (p = 0.024). No differences were found for limitations in everyday life (p = 0.607), Sense of Coherence (p = 0.638), the Spine Deformity Index (p = 0.171) and loss of height (p = 0.619). All analyses were corrected for age. Concurrent medication was not found to influence the results. Findings suggest that time after fracture is an important variable when considering QoL and well-being after vertebral fracture and should, therefore, be considered in future studies.

Electronic Resource

1436-3771

Key words Saliva ; Biomarkers ; Detection ; Cancer ; Oncogenes ; c-erbB-2 ; CA 15 ; 3

Springer Online Journal Archives 1860-2000

Medicine

Abstract  Two markers used to aid in the diagnosis and treatment of breast cancer were examined in the saliva of a cohort of 135 healthy women. The investigators detected the presence of cancer antigen 15–3 (CA 15–3) and c-erbB-2 in the saliva sampled from the 135 women. The marker concentrations for CA 15–3 and c-erbB-2 were also evaluated and compared in terms of tobacco usage, menopausal status, estrogen usage, systemic diseases, prescription medications, race, and age. The results of the study showed no association between the aforementioned variables and salivary marker concentrations. The results of this study establish a baseline for measuring the biomarkers in the saliva of women with no evidence of malignant disease and add further support to the notion that salivary concentrations of CA 15–3 and c-erbB-2 may be useful in the detection of breast cancer and/or the post operative follow-up of patients being treated for carcinoma of the breast.

Electronic Resource

1432-0428

Intravenous glucose tolerance test ; first phase insulin secretion ; second phase insulin secretion ; glucose potentiation ; tolbutamide

Springer Online Journal Archives 1860-2000

Medicine

Summary The relationship between the pre-stimulus glucose level and immunoreactive insulin responses to a glucose challenge (20-g IV) was studied in normal subjects. When the steady-state pre-stimulus glucose concentration was lowered by a 0.33 mU· kg-1· min-1 insulin infusion or raised by a 900mg/ min glucose infusion, no effect on first phase insulin secretion (mean Δ 3–5 min insulin level) was observed. In contrast, the second phase response (10–60 min insulin area after glucose pulse) to intravenous glucose fell during insulin infusion and increased during the glucose infusion. Overall, a linear relationship was found between the change of pre-stimulus glucose level from the control to that during the insulin or glucose infusion and the change in second phase response (r=0.65, n = 14, p〈0.02). The effect of tolbutamide infusion (7 mg·m-2· min-1) when compared with saline control was to increase both first phase (+54 ±13 mU/1, n=8, p 〈0.001, mean±SEM) and second phase (+972±256mU · mur-1 · 1-1, P〈0.01) insulinsecretion. It is concluded that the first phase response to a glucose pulse is independent of the steady-state pre-stimulus glucose concentration and is directly enhanced by tolbutamide; in contrast, second phase is related to both the steady-state pre-stimulus glucose level and tolbutamide. These findings suggest that changes in basal or pre-stimulus plasma glucose during therapy with sulphonylurea drugs may be expected to influence the second phase insulin responses to glucose challenge.

Electronic Resource

1432-1238

Key words Lateral posture ; Hemodynamic effects ; Kinetic therapy ; Respiratory failure ; Right ventricular function ; Atrial natriuretic peptide

Springer Online Journal Archives 1860-2000

Medicine

Abstract Objective: To quantify the hemodynamic effects of turning critically ill, mechanically ventilated patients to the extreme left and right lateral postures. Design: Prospective investigation. Setting: Eight-bed intensive care unit in a university hospital. Patients: Twelve consecutive patients presenting with severe respiratory failure and requiring continuous positive inotropic support. Interventions: All patients were mechanically ventilated and placed in a kinetic treatment system. They were positioned in the supine, left dependent, and right dependent postures, resting for 15 min in each position. Measurements and results: Hemodynamic measurements, assessments of right ventricular function, and determinations of intrathoracic blood volume were performed in three different positions. Concentrations of atrial natriuretic peptide in plasma were quantified. In three patients, the findings were controlled by transesophageal echocardiography. Cardiac index [median (range) 5.5 (3.2–8.1) vs 4.3 (3.2–7.5) l/min per m2, p〈0.01], intrathoracic blood volume [1125 (820–1394) vs 1037 (821–1267) ml/m2, p〈0.01], and right ventricular end-diastolic volume [130 (83–159) vs 114 (79–155) ml/m2, p〈0.05] increased significantly in the left dependent position compared to supine. Mean arterial pressure did not change. Atrial natriuretic peptide levels rose from 140 to 203 pg/ml. In the right dependent position, we found a marked decrease in the mean arterial pressure [85 mmHg (supine) to 72 mmHg (right dependent), p〈0.01]. Cardiac index and intrathoracic blood volume were unchanged, but right ventricular end-diastolic volume decreased from 114 to 102 ml/m2 (p〈0.05) Additionally, atrial natriuretic peptide levels decreased significantly (median Δ value: 37 pg/ml). In echocardiographic controls we found an increase in right ventricular end-diastolic diameters in the left dependent position and shortened diameters in the right dependent position. Conclusions: Extreme lateral posture affects the cardiovascular system in critically ill, mechanically ventilated patients: in the left dependent position a ”hyperdynamic state“ is reinforced, while the right decubitus position impairs right ventricular preload and predisposes to hypotension. Echocardiography and changes in plasma atrial natriuretic peptide values indicate that these findings are due to altered distensibility of the right ventricle caused by regional intrathoracic gravitational changes. We conclude that the duration and the angle of lateral posture should be restricted in hemodynamically unstable patients.

Electronic Resource