Pion electromagnetic form factor at spacelike momenta.

A novel method is employed to compute the pion electromagnetic form factor, F(π)(Q²), on the entire domain of spacelike momentum transfer using the Dyson-Schwinger equation (DSE) framework in QCD. The DSE architecture unifies this prediction with that of the pion's valence-quark parton distribution amplitude (PDA). Using this PDA, the leading-order, leading-twist perturbative QCD result for Q²F(π)(Q²) underestimates the full computation by just 15% on Q²â‰³8 GeV², in stark contrast to the result obtained using the asymptotic PDA. The analysis shows that hard contributions to the pion form factor dominate for Q²â‰³8 GeV², but, even so, the magnitude of Q²F(π)(Q²) reflects the scale of dynamical chiral symmetry breaking, a pivotal emergent phenomenon in the standard model.

Pion distribution amplitude from lattice QCD.

A method is explained through which a pointwise accurate approximation to the pion's valence-quark distribution amplitude (PDA) may be obtained from a limited number of moments. In connection with the single nontrivial moment accessible in contemporary simulations of lattice-regularized QCD, the method yields a PDA that is a broad concave function whose pointwise form agrees with that predicted by Dyson-Schwinger equation analyses of the pion. Under leading-order evolution, the PDA remains broad to energy scales in excess of 100 GeV, a feature which signals persistence of the influence of dynamical chiral symmetry breaking. Consequently, the asymptotic distribution φπ(asy)(x) is a poor approximation to the pion's PDA at all such scales that are either currently accessible or foreseeable in experiments on pion elastic and transition form factors. Thus, related expectations based on φ φπ(asy)(x) should be revised.

Imaging dynamical chiral-symmetry breaking: pion wave function on the light front.

We project onto the light front the pion's Poincaré-covariant Bethe-Salpeter wave function obtained using two different approximations to the kernels of quantum chromodynamics' Dyson-Schwinger equations. At an hadronic scale, both computed results are concave and significantly broader than the asymptotic distribution amplitude, φ(π)(asy)(x)=6x(1-x); e.g., the integral of φ(π)(x)/φ(π)(asy)(x) is 1.8 using the simplest kernel and 1.5 with the more sophisticated kernel. Independent of the kernels, the emergent phenomenon of dynamical chiral-symmetry breaking is responsible for hardening the amplitude.

Attitudes related to technology for active and healthy aging in a national multigenerational survey.

Research is needed to understand attitudes toward and adoption of the broad range of technologies available to support active and healthy aging in different generations. The present article gives an overview of the GenerationTech survey and sample, and describes attitudes and acceptance related to technology in general and as a means to support active and healthy aging. A national survey was conducted with a random sample (n = 2,121) including men and women from three generations (30-39, 50-59 and 70-79-year-olds) in Sweden. The generations shared some attitudes toward and acceptance of technologies for active and healthy aging. However, what kind of technologies are preferred to support active and healthy aging and the reasons for using certain technologies differed by generation. The findings could help guide the development and implementation of technologies for active and healthy aging throughout the aging process.

A scoping review of public building accessibility.

BACKGROUND: The built environment needs to be designed so that all people can participate in the activities they want and need to do. Yet, accessibility is difficult to put into practice, and accessibility issues tend to be overlooked in the building and planning processes. OBJECTIVES: The aim of this scoping review was to summarize the research front in the area of accessibility to public buildings. Specific aims were to identify knowledge gaps, to identify access activities in relation to environmental features and to link to predominant activities in terms of the International Classification of Functioning, Disability and Health (ICF). METHODS: A literature search was performed in PubMed, PsycINFO, Inspec, Embase and Cochrane databases. Articles in English based on original empirical studies investigating accessibility of public buildings for adults aged ≥18 years with functional limitations were considered. RESULTS: Of the 40 articles included, ten involved study participants, while 30 only examined buildings using instruments to assess accessibility. In addition, the psychometric properties were only tested for a few of them. All articles concerned mobility and several visual limitations, while few addressed cognitive or hearing limitations. Ten main access activities were identified, from using parking/drop-off area to exiting building. CONCLUSIONS: By using the ICF and theoretically relating the accessibility problems to activities, the results revealed that there are large knowledge gaps about accessibility to public buildings for older people and people with functional limitations and that there is a need for more methodological considerations in this area of research.

Zoledronic acid inhibits the function of Toll-like receptor 4 ligand activated monocyte-derived dendritic cells.

Zoledronic acid (ZA) is a nitrogen-containing bisphosphonate with antitumor activity used to treat patients with malignant diseases. ZA treatment induces, as a side effect, inflammatory responses, which are accompanied by expansion of gammadelta T cells. In our study, we analyzed the function and differentiation of monocyte-derived immature and lipopolysaccharide (LPS)-stimulated dendritic cells (moDCs) treated with different ZA concentrations, which are achieved in patients. We found that moDC activation with TLR4 ligand LPS is modulated by ZA. The expression of maturation markers was diminished with increasing ZA levels upon LPS activation. The migratory capacity, interleukin-12 secretion and generation of cytotoxic- T-cell responses were reduced at higher ZA levels. Increasing ZA concentrations downregulated nuclear factor-kappaB family members and interferon-regulatory factor (IRF)-3. Surprisingly, in immature moDCs, low ZA concentrations caused upregulation of RelB, c-Rel, IRF-3 and IRF-8. We conclude that ZA concentrations used to treat patients have inhibitory effects on DC activation. This might lead to immunosuppression or result in infectious complications.

Comparison of CT during arterial portography and MR during arterial portography in the detection of liver metastases.

OBJECTIVE: This study compared MR during arterial portography (MRAP) with CT during arterial portography (CTAP) with regard to the detection and differentiation of liver metastases before surgery. MATERIALS AND METHODS: Fifteen patients with liver metastases were enrolled before surgery according to the guidelines of our institutional review board and good clinical practice. After mesentericography, unenhanced scans (Volume Zoom) were performed initially. For CTAP, the contrast medium was injected through the superior mesenteric artery. Images were acquired in portal and delayed enhancement. The MR protocol (1.5 T; Magnetom Symphony) started with T1-weighted fast low-angle shot (FLASH) T2-weighted turbo spin echo (TSE). MRAP followed with gadolinium-enhanced dynamic T1-weighted 3D FLASH. Delayed-phase T1-weighted 2D FLASH axial images were performed 2 min after IV injection of the contrast medium. Qualitative and quantitative evaluation of CTAP and MRAP was performed by three blinded radiologists regarding the number of lesions and their size, localization, and differential diagnosis. RESULTS: The overall sensitivity in detecting liver metastases was 97% with MRAP and 93% with CTAP (p > 0.05, not significant [n.s.]). The specificity was calculated to be 97% for MRAP and 82% for CTAP (p < 0.0001, statistically significant [s.s.]). The differences in sensitivity were more accentuated if only lesions 10 mm or smaller were considered (95% vs 88%, p > 0.05, n.s.), for which the respective specificities were 95% and 80% (p < 0.0014, s.s.). Improvements in sensitivity and specificity were associated with a higher lesion-to-liver contrast-to-noise ratio (59.4 +/- 51.0 for MRAP vs 10.4 +/- 7.3 for CTAP) and resulted in higher diagnostic confidence in the differential diagnosis of liver lesions (p < 0.001, s.s.) and better interobserver agreement (median kappa value, 0.88 vs 0.63). CONCLUSION: MRAP proved to be a reliable method in the preoperative detection of small liver metastases in particular, with a higher sensitivity and specificity than CTAP. If organizational difficulties of MRAP can be overcome, MRAP could be considered instead of CTAP in the preoperative invasive evaluation of metastatic liver disease.

Characterization of BAX inhibitor-1 as a novel leukemia-associated antigen.

Using dendritic cells (DCs) electroporated with whole RNA isolated from blasts of a patient with acute myeloid leukemia (AML), we were able to generate leukemia-specific cytotoxic T lymphocytes (CTLs) capable of recognizing the leucemic cells. To identify T-cell epitopes mediating lysis of malignant cells, peptides were eluted from the patient's blasts and analyzed by mass spectrometry (LC/MS)-based peptide sequencing. Using this approach, an HLA-A24-binding peptide derived from Bax inhibitor-1 (BI-1), a regulator of apoptosis pathways, was identified as an epitope recognized by the generated CTLs. To further characterize this novel antigenic peptide, CTLs were induced using DCs electroporated with RNA coding for BI-1 or pulsed with the cognate peptide. These CTLs generated from healthy donors in vitro efficiently lysed the patient's blasts as well as other HLA-matched leukemic cells. In conclusion, we identified a BI-1 peptide as a novel immunogenic tumor-associated antigen (TAA) in AML. In vitro induction of BI-1-specific CTLs by RNA transfection or pulsing of DCs with the synthetically generated peptide was a feasible and highly effective method to generate leukemia-specific CTLs. As BI-1 is (over-) expressed in a broad variety of malignancies, it may represent an interesting novel TAA in the context of cancer vaccines.

Post-transcriptional regulation of adapter molecules by IL-10 inhibits TLR-mediated activation of antigen-presenting cells.

Toll-like receptors (TLRs) act to sense the environment for microbial products and submit danger signals to antigen-presenting cells (APCs) resulting in activation of complex immune responses. In this study, we analyzed the function of human monocyte-derived APCs generated in vitro in the presence of interleukin (IL)-10 upon activation by TLR ligands. Exposure of these APCs to IL-10 resulted in a skewed phenotypic maturation in response to stimuli provided by the TLR ligands, a reduced cytokine production, such as IL-12, IL-6 or tumor necrosis factor-alpha, and impaired capacity to stimulate T-cell activation. Furthermore, CCR7 upregulation in APCs exposed to TLR stimulation as well as migration towards CCL19/MIP-3beta were strongly reduced. IL-10 was found to downregulate MyD88, IRAK1 (IL-1 receptor-associated kinase) and tumor necrosis factor receptor-associated factor 6, essential adaptor molecules for TLR signaling, and to decrease TLR-induced nuclear expression of the nuclear factor-kappaB transcription factors c-Rel and Rel-B as well as interferon regulatory factor (IRF)-3 and IRF-8. This was not due to the inhibition of the mitogen-activated protein kinase pathway, but was rather mediated by the blockage of the PI3K signaling cascade. Interestingly, the inhibition of proteins involved in TLR signaling, such as MyD88, IRAK1 and mammalian target of rapamycin, was due to a selective post-transcriptional regulation.

Pair production and optical lasers.

Electron-positron pair creation in a standing wave is explored using a parameter-free quantum kinetic equation. Field strengths and frequencies corresponding to modern optical lasers induce a material polarization of the QED vacuum, which may be characterized as a plasma of e+e- quasiparticle pairs with a density of approximately 10(20) cm-3. The plasma vanishes almost completely when the laser field is zero, leaving a very small residual pair density n(r) which is the true manifestation of vacuum decay. The average pair density per period is proportional to the laser intensity but independent of the frequency nu. The density of residual pairs also grows with laser intensity but n(r) proportional to nu(2). With optical lasers at the forefront of the current generation, these dynamical QED vacuum effects can plausibly generate 5-10 observable two-photon annihilation events per laser pulse.

Chlamydophila pneumoniae respiratory tract infection aggravates therapy refractory bronchitis or pneumonia in childhood.

BACKGROUND: Chlamydophila pneumoniae was frequently found in bronchial secretions of children with therapy-refractory bronchitis or pneumonia. It was studied, how the agent modifies the course of disease and what findings are associated with the infection. PATIENTS AND METHODS: Bronchial secretions obtained at bronchoscopy of 428 children were studied for C. pneumoniae infection using polymerase chain reaction with enzyme immunoassay detection. Children tested negative and positive were compared for their clinical findings. RESULTS: C. pneumoniae was found in 143 children (33 %). A C. pneumoniae infection has been found to be associated with a purulent bronchial inflammation (90/143 vs. 144/285, p = 0.02), a Streptococcus pneumoniae co-infection (13/143 vs. 6/285, p = 0.002) and a restrictive disturbance (11/51 vs. 8/93, p = 0.04). Purulent inflammation (Odds ratio 7.9; 95 % confidence interval [CI] 1.6-39.3), 2 co-infections (Odds ratio 14.3; 95 % CI 1.4-144.4) and co-infection with M. pneumoniae (4/4 versus 9/26, p = 0.03; Mantel Haentzel 3.0; 95 % CI 1.1-8.0) were identified as factors more often associated with a restrictive disturbance in children with bronchial C. pneumoniae infection. An adequate antibiotic therapy improved pulmonary function. No association was found for wheezing, eosinophil inflammation of the nasal mucosa, alpha-1 antitrypsin or immunoglobulin deficiency in serum, level of secretory IgA in bronchial mucus, pathological lung scintigram, gastro-esophageal reflux disease, sweat test and other co-infections. CONCLUSIONS: In children with therapy-refractory bronchitis or pneumonia bronchial C. pneumoniae infection was associated with a more severe disease in case of several, mostly bacterial co-infections. Adequate antibiotic therapy for C. pneumoniae infection has been demonstrated to improve pulmonary function.

Wrongful life.

KIE: A lawyer in the Office of the General Counsel of the American Medical Association differentiates among various dissimilar legal theories described as wrongful life theories, and briefly considers the legislative and judicial responses of several states. Schmidt concludes that problems of wrongful life involve an evaluation not only of law, but also of medicine, morals, and public policy. As genetic counseling, prenatal diagnosis, and fetal therapy are refined, related ethical questions will have to be answered, and the generallly unfavorable legal response to wrongful life actions may be reversed.^ieng

Quality of well being in patients with fibromyalgia.

OBJECTIVE: The Quality of Well-being Scale (QWB) is a generic measure of health related quality of life that can be used for population monitoring, measurement of clinical outcomes, or cost effectiveness analysis. We report data on the validity of the QWB for patients with fibromyalgia (FM) and compare the effect of FM to that of other chronic diseases. METHODS: The participants were 594 people recruited from a private health maintenance organization with a confirmed diagnosis of FM. The QWB was administered, along with measures of self-rated health status, physical functioning, pain, stiffness, anxiety, sleep, and depression. The QWB places levels of wellness on a continuum ranging from 0.0 (for death or the equivalent of being dead) to 1.0 (for optimum functioning without symptoms). RESULTS: Patients with FM had mean QWB scores of 0.559 (SD 0.074), which is lower than scores reported for patients in most other chronic disease categories. QWB was significantly correlated with measures of physical functioning, stiffness, anxiety, depression, pain, and sleep quality. CONCLUSION: Evidence supports the validity of the QWB for patients with FM. Patients with FM obtain lower scores on the QWB than patients with diagnoses of chronic obstructive pulmonary disease, rheumatoid arthritis, atrial fibrillation, advanced cancer, and several other chronic diseases. Although FM is generally considered a syndrome rather than a disease, substantial disability is experienced by people with this diagnosis.

Quantum effects with an x-ray free-electron laser.

A quantum kinetic equation coupled with Maxwell's equation is used to estimate the laser power required at an x-ray free-electron laser (XFEL) facility to expose intrinsically quantum effects in the process of QED vacuum decay via spontaneous pair production. A 9 -TW-peak XFEL laser with photon energy of 8.3 keV could be sufficient to initiate particle accumulation and the consequent formation of a plasma of spontaneously produced pairs. The evolution of the particle number in the plasma will exhibit non-Markovian aspects of the strong-field pair production process, and the plasma's internal currents will generate an electric field whose interference with that of the laser leads to plasma oscillations.

Excluding linkage between panic disorder and the gamma-aminobutyric acid beta 1 receptor locus in five Icelandic pedigrees.

The GABAA receptor subunits are candidate genes for panic disorder because the receptor is the site of action for the anxiolytic effects of the benzodiazepines. We tested for linkage between a tetranucleotide repeat polymorphism at the GABAA beta 1 locus, located on chromosome 4p13-p12, and panic disorder defined by DSM-III-R criteria in 5 Icelandic pedigrees. Both a narrow affection status (definite panic disorder and agoraphobia) and a broad one (including probable cases of these disorders) were tested. With the narrow definition, at a recombination fraction of 0.00, the lod scores in the 5 pedigrees ranged from -3.240 to +0.063, the total score across all 5 pedigrees being -8.299. With the broad definition at the same recombination fraction, the individual lod scores ranged from -2.614 to -0.489, with the total being -8.089. Thus, linkage between panic disorder/agoraphobia and the GABAA beta 1 locus in these pedigrees is exceedingly unlikely.